KR100359009B1 - Image encoding apparatus and method - Google Patents

Abstract

An image coding apparatus and method for improving the compression efficiency and reducing image quality deterioration when hierarchically encoding image data, wherein the image data is displayed by using a recursive hierarchical representation to hierarchically encode the image data. By performing the division of one adaptive block and encoding, and transmitting the hierarchical coded data obtained as a result of the division, adaptively dividing the block of the lower layer is obtained, and as a result, the amount of information such as a flat portion of the image is obtained. I can cut it.

Description

Image coding apparatus and method

The present invention relates to a picture coding apparatus and method of the present invention, and can be applied to, for example, a picture coding apparatus for dividing predetermined picture data into a plurality of picture data having different resolutions.

Background Art Conventionally, such type of image coding apparatus has hierarchically encoded input image data using a hierarchical coding method such as pyramid coding (Japanese Patent Application Laid-Open No. 5-142836). In the picture coding apparatus, the second hierarchical data having a lower resolution than the first hierarchical data, and the third hierarchical data having a lower resolution than the second hierarchical data, using high-resolution input image data as the first hierarchical data. Data, ... are formed recursively in sequence, and the plurality of hierarchical data is transferred to a communication path or a transmission path serving as a recording / reproduction boundary.

The first, second, third, and fourth hierarchical data D11, D12, D13, and D14 having different resolutions from the encoders 11, 12, 13, and 14 as a result are compressed in a predetermined order. It is sent to the transmission line.

The first to fourth hierarchical data D11 to D14 thus transmitted are decoded by the image decoding device 20 shown in FIG. That is, the first to fourth hierarchical data D11 to D14 are decoded by the decoders 21, 22, 23, and 24, respectively, and as a result, the fourth hierarchical data D24 is first output from the decoder 24. do.

The output of the decoder 23 is added to the interpolation data of the fourth hierarchical data D24 obtained by the interpolation filter 26 in the addition circuit 29, and the third hierarchical data D23 is thereby restored. Similarly, the output of the decoder 22 is added to the interpolation data of the third hierarchical data D23 obtained by the interpolation filter 27 in the addition circuit 30, and thereby the second hierarchical data D22 is restored. In addition, the output of the decoder 21 is added to the interpolation data of the second hierarchical data D22 obtained from the interpolation filter 28 in the addition circuit 31, thereby reconstructing the first hierarchical data D21.

Here, in the picture coding apparatus for realizing the hierarchical coding method, in order to divide and encode input image data into a plurality of hierarchical data, the data amount increases by a hierarchical component, and as compared with the high-performance coding method that does not use hierarchical coding. There is a problem that the compression efficiency is lowered. In addition, when trying to improve the compression efficiency, there is a problem that image quality deterioration occurs by a quantizer applied between the hierarchical data.

Disclosure of the Invention

In view of the above points, the present invention proposes an image encoding method and an image encoding apparatus which can improve compression efficiency when hierarchically encoding image data and reduce degradation of the quality.

In order to solve this problem, in the present invention, an image encoding apparatus for encoding an input image signal in order to recursively generate a plurality of hierarchical data having different resolutions, wherein an adaptive block corresponding to the property of the image data is used. It is possible to adaptively divide image data into blocks by providing determination dividing means for determining a dividing method and dividing image data according to the determination result, and transmission means for transmitting hierarchical coded data obtained from the determination dividing means. .

Further, in the present invention, in the image encoding apparatus encoding an input image signal in order to generate a plurality of hierarchical data having a plurality of different resolutions sequentially recursively, the hierarchical data of each hierarchical data except for the lowest hierarchical data having the lowest resolution is used. Detecting a block activity of a given block, generating a division decision flag for determining a partitioning scheme of the block based on the block activity, and determining a result indicating that the block activity is smaller than a predetermined threshold is obtained. When generating a segmentation stop flag for stopping division of the plurality of lower blocks corresponding to the block, determining the block activity of the plurality of lower blocks and controlling the transmission of the hierarchical data of the plurality of lower blocks. The decision control means for generating the By providing a transmission means for transmitting together with the hierarchical data, the determination flag is transmitted together with the image data divided into blocks.

Further, in the present invention, in the image encoding apparatus for encoding an input image signal in order to generate a plurality of hierarchical data having a plurality of different resolutions sequentially recursively, the hierarchical data of each hierarchical data except for the highest hierarchical data having the lowest resolution is used. When a block activity of a predetermined block is detected, a division determination flag for generating a division of a block is generated based on the block activity, and a determination result indicating that the block activity is smaller than a predetermined threshold is obtained. A generation stop flag for temporarily stopping division of the plurality of lower blocks corresponding to the block is generated temporarily, and a determination result indicating that the block activity of at least one block of the plurality of lower blocks is equal to or greater than a predetermined threshold is obtained. Change split stop flag to split continue flag to continue splitting when It may determine the division determination flag to determine a division type of the block by what it to install a transmission means for transmitting with the determination control means, and each layer of data, the determination flag of each block encoded.

Further, in the present invention, in the image encoding apparatus for encoding an input image signal in order to generate a plurality of hierarchical data having a plurality of different resolutions sequentially recursively, all the hierarchical data except the highest hierarchical data having the lowest resolution are used. When a block activity of a block is detected, a division decision flag for generating a division of each block based on the block activity is generated, and a determination result indicating that the block activity is smaller than a predetermined threshold is obtained. Decision control means for generating a segmentation stop flag for stopping division of the block and generating a segmentation continuation flag for continuing the division of the block when a determination result indicating that the block activity is equal to or greater than a threshold is obtained; Transmitting means for transmitting the determination flag of the file together with the encoded layer data; It becomes possible to independently determine the division type of the block By installation.

In the present invention, in order to generate a plurality of hierarchical data having a plurality of different resolutions sequentially recursively, image coding for encoding an input image signal composed of a plurality of image forming signals having mutual relations to form an image. In the apparatus, a block activity corresponding to a first signal of a plurality of image forming signals is detected for a predetermined block of hierarchical data except for the highest hierarchical data having the lowest resolution, and based on the block activity, the block activity is detected. Generate a division decision flag for determining a division scheme of the sub-blocks corresponding to the block, and when the determination result indicating that the block activity is smaller than a predetermined threshold is obtained, the division of the sub-blocks corresponding to the block or blocks is performed. In addition to generating a partition stop flag for stopping, the block activity A determination for generating a segmentation continuation flag for continuing division of a block or a lower block corresponding to the block when a determination result indicating that the threshold value is abnormal is obtained, and determining a threshold value based on a second signal in the plurality of image forming signals; By providing the control means, the threshold value is set by the first signal such as the luminance signal, and the second signal such as the color signal can be divided.

Further, in the present invention, in the image encoding apparatus for encoding an input image signal in order to generate a plurality of hierarchical data having a plurality of different resolutions sequentially recursively, in order to control the amount of generated information to a target value, Threshold detection means for detecting a threshold which is a determination criterion of the block activity based on the block activities of all blocks, and block activity of a predetermined block of each layer data except for the highest layer data having the lowest resolution; On the basis of the result of the comparison of the block activity and the threshold value, a partitioning method for partitioning the partition or a lower block corresponding to the block is determined, and partitioning means for partitioning is provided, and transmission means for transmitting hierarchical coded data obtained from the decision partitioning means. So that when the block activity is below a predetermined threshold (i.e., When the change is small), the amount of information generated is controlled by the division process of the lower layer.

Further, in the present invention, an image coding apparatus for encoding an input image signal in order to recursively generate a plurality of hierarchical data having a plurality of different resolutions, the adaptive block division method corresponding to the property of the image data is employed. The determination and dividing means for dividing the image data according to the determination result, and the transmission means for transmitting the variable length data after the fixed length data is transmitted to the hierarchical coded data obtained from the determining means. To improve.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[1] principle of hierarchical coding

Fig. 3 shows, as a whole, the case of hierarchically encoding a still picture such as a high-definition television signal as a principle of hierarchical coding according to the present invention. In this hierarchical coding, upper hierarchical data is generated by a simple arithmetic mean of lower hierarchical data, and the lower hierarchical data to be transmitted is reduced to realize a hierarchical structure that does not increase the amount of information. In addition, in the decoding of the lower layer data from the upper layer data, the amount of information in the flat portion is reduced by adaptively controlling the division based on the activity for each block.

Here, the activity is represented by the maximum value, average value, absolute value, standard deviation, or n sum of interlayer difference data D41 to D44 in a predetermined block when the lower layer data area corresponding to the upper layer data is defined as "block". Is a correlation value. In other words, when the activity is low, the block is a flat block.

Further, in encoding inter-layer difference data performed for lower layer data, high efficiency is achieved by switching the quantization characteristic for each block without additional code based on the activity of the upper layer data.

That is, in the hierarchical structure of the hierarchical encoding, the high quality television signal inputted first is selected as the lowest hierarchical data, and the following equation is applied to four pixels X1 to X4 in the small blocks of two lines x two pixels of the lowest hierarchical data.

The arithmetic mean expressed by is taken and the value m is the value of the upper layer data. In the lower layer data,

As indicated by, the hierarchical structure is constructed with the same amount of information as the original four-pixel data by preparing only three pixels of the upper hierarchical data and the difference data between layers.

On the other hand, when decoding lower layer data, 3 pixels X _{1 to} X ₃ are represented by the following equation.

As shown in Fig. 2, the inter-layer difference data ΔXi is added to the average value m of the upper layer data to obtain the decoding value E [X _i ].

As indicated by, the decoding value E [X ₄ ] is determined by subtracting three decoding values of the lower layer data from the average value m of the upper layer data. E [] here means a decoding value.

In this hierarchical encoding, the resolution and the data amount are four times per layer from the upper layer to the lower layer, but the redundancy is reduced by prohibiting the division in the flat part. A flag indicating the presence or absence of this division is prepared in units of 1 bit and block. The determination of the necessity of partitioning at the lower layer is a local activity, for example, determined as the maximum value of the inter-layer difference data.

As an example of this hierarchical encoding, the result of the adaptive division in the case where the image is divided into five hierarchies using an HD standard image (Y signal) of ITE is shown in FIG. In the figure, although the ratio of the original pixel number example of the number of pixels of each layer at the time of changing the threshold value with respect to the maximum inter-layer difference data is shown, the redundancy is also reduced based on spatial correlation. In the reduction efficiency, if the threshold for the maximum inter-layer difference data changed by the image is changed from 1 to 6, the average reduction ratio is 28 to 69%.

In practice, lower layer data is generated by quadrupling the resolution of upper layer data, and at this time, the signal level width can be effectively reduced by encoding inter-layer difference data from the upper layer data. The case of the fifth layer by the hierarchical coding described above with respect to FIG. 4 is shown in FIG. 5, but the hierarchies are listed below to be the first to fifth hierarchies. Compared to 8-bit PCM data of the original picture, the signal level width can be reduced. In particular, since the first to fourth layers having a large number of pixels are difference data between layers, a significant reduction is achieved, and the efficiency is improved by subsequent quantization. As can be seen from FIG. 5, the cutting efficiency is less dependent on the pattern and is effective for the whole picture.

In addition, error propagation remains in the block by creating upper layer data using the average value of lower layer data, thereby converting the lower layer data into a difference from the average value of the upper layer data, and excellent efficiency can be obtained therefrom. . In fact, in hierarchical coding, there is a correlation in activities between layers at the same spatial location, and the quantization used by the receiving side (decode side) as the transmitting side (encoding side) is determined by determining the quantization characteristics of the lower layer data from the quantization result of the higher layer data. Run the adaptive quantizer without the need to send information (except for the initial value).

In practice, an image is hierarchically coded based on the above-described five-level hierarchical structure to represent a plurality of resolutions, adaptive segmentation and adaptive quantization using the hierarchical structure is performed, and thus an HD standard image (8-bit Y / P _B / P _R ) can be compressed to about 1/8. In addition, run-length coding is performed on each layer of additional code prepared for adaptive division in each layer to improve compression efficiency. As a result, an image of sufficient image quality is obtained in each layer, and a good image without visual deterioration can also be obtained in the final lowest layer.

[2] first embodiment

(1) The picture coding apparatus of the first embodiment

In FIG. 6, 140 denotes the image encoding apparatus according to the present invention as a whole. For example, input image data D131, which is a still image such as a high-definition television signal, is divided into five layers by the above-described hierarchical coding method. The resulting lowest hierarchical data and inter-layer difference data for four layers are encoded. In the picture encoding apparatus 140, the input image data D131 is input to the first difference circuit 141 and the first averaging circuit 142.

As shown in FIG. 7, the first averaging circuit 142 uses the pixel X1 of the second hierarchical data D132 from the four pixels X1 (1) to X4 (1) of the input image data D131, which is the first hierarchical data as the lowest hierarchical data. Create 2). The pixels X2 (2) to X4 (2) adjacent to the pixel X1 (2) of the second hierarchical data D132 are similarly generated by the four pixel average of the first hierarchical data D131. The second hierarchical data D132 is input to the second difference circuit 143 and the second averaging circuit 144. The second averaging circuit 144 generates the pixel X1 (3) of the third hierarchical data D133 by, for example, a four-pixel average of the pixels X1 (2) to X4 (2) of the second hierarchical data D132. The pixels X2 (3) to X4 (3) adjacent to the pixel X1 (3) of the third hierarchical data D133 are similarly generated by the four pixel average of the second hierarchical data D132.

The third hierarchical data D133 is input to the third difference circuit 145 and the third averaging circuit 146. As described above, the third averaging circuit 146 also uses the four-pixel average of the pixels X1 (3) to X4 (3) of the third hierarchical data 133 to select the pixels X1 (4) to X4 (4) of the fourth hierarchical data D134. Create The fourth hierarchical data D134 is input to the fourth differential circuit 147 and the fourth averaging path 148. Similarly, the fourth averaging circuit 148 generates the fifth hierarchical data D135, which is the highest hierarchical layer, by the four-pixel average of the pixels X1 (4) to X4 (4) of the fourth hierarchical data D134.

In fact, the block size of the first to fifth hierarchical data D131 to D135 is 1 × 1 when the block size of the first hierarchical data D131, which is the lowest hierarchical layer, is 1/2 × 1/2. The third layer data D133 is 1/4 x 1/4, the fourth layer data D134 is 1/8 x 1/8, and the fifth layer data D135, which is the highest layer data, is 1/16 x 1/16.

In this way, the first to fourth hierarchical data other than the fifth hierarchical data D135 of the highest hierarchical data among the five hierarchical data D131 to D135 are the first, second, third and fourth as described above with respect to expression (2). The difference circuits 141, 143, 145, and 147 are differentially calculated from each other, and the result of this calculation is generated as the inter-layer difference data D140, D141, D142, and D143.

In fact, firstly, the fifth layer data D135 and the fourth layer data 134 are differentially calculated in the fourth difference circuit 147, and the inter-layer difference data D143 of the fourth layer is generated, and then in the third difference circuit 145. The fourth layer data D134 and the third layer data D133 are differentially calculated to generate inter-layer difference data D142 of the third layer. Next, the third layer data D133 and the second layer data D132 are differentially calculated in the second difference circuit 143, and the interlayer difference data D141 of the second layer is generated, and finally, the second layer data in the first difference circuit 141. D132 and the first layer data D131 are differentially calculated to generate inter-layer difference data D140 of the first layer.

As described above, in the image encoding device 140 of the present embodiment, the fifth hierarchical data 135 and the interlayer difference data D143 to D140 of the fourth to the first hierarchical layers are sequentially generated in that order. At this time, in the image encoding apparatus 140, as described above with respect to Equation (2), lower layer data is generated in association with higher layer data, and among the lower layer 4 pixels corresponding to the upper layer 1 pixel by encoders 154 to 157, respectively. By subtracting one pixel, the number of pixels as an encoding target is increased, thereby degrading the compression efficiency even when image data is decomposed into multiple layers and encoded.

These interlayer difference data D140 to D143 are input to the division control circuits 150, 151, 152 and 153, respectively. The division control circuits 150 to 153 make a determination every time from the inter-layer difference data D143 to D140 with the threshold value Tha of the block activity indicating whether or not the predetermined block in the inter-layer difference data D140 to D143 is a flat portion. It is determined whether or not to transmit the inter-layer difference data D142 to D140. For example, when the activity in the block of the inter-layer difference data D143 of the fourth layer is A,

When is satisfied, it is determined that the image data is a flat portion and the block is hard to cause deterioration, and a determination flag F for not transmitting is set. Accordingly, the division control circuits 150 to 153 make a determination every time with respect to the threshold value Tha of the block activity for all blocks of the inter-layer difference data D140 to D143 of each layer, and the decision flag F indicating whether or not to transmit the corresponding block is controlled. It is sent to the code generating circuit 159.

At the same time, the division control circuit 153 sends a control signal C3 to the division control circuit 152 of the third layer. As a result, the division control circuit 152 of the third layer unconditionally stops the transmission of the difference data D142 between layers. When the division control circuit 152 of the 3rd and 2nd layer receives control signals C3 and C2 which indicate unconditional interruption of transmission, it transmits it as control signals C2 and C1 to the lower division control circuits 151 and 150 as it is, respectively. As a result, transmission of the inter-layer difference data D142 to D140 of all lower hierarchies is unconditionally stopped by the control of the division control circuits 153 to 150.

In this way, the inter-layer difference data D140 to D143 of each layer sent from the division control circuits 150 to 153 is sent to the encoders 154 to 157. The fifth layer data D135 of the uppermost layer is transmitted to the encoder 158 as it is. The encoders 154 to 157 compression-code the inter-layer difference data D140 to D143 by a nonlinear encoding method suitable for encoding the differential data, thereby generating the first to fourth hierarchical compressed coded data D145 to D148. The encoder 158 compresses and codes the fifth hierarchical data D135 by a linear encoding method suitable for encoding the image data of the average data, thereby generating the fifth hierarchical compressed coded data D149.

The determination flag F sent out from each of the division control circuits 150 to 153 is input to the control code generation circuit 159. Accordingly, the control code generation circuit 159 generates a control code D150 composed of decision flags F for each layer and each block. The control code D150 and the first to fifth hierarchical compressed coded data D145 to D149 are encoded by run-length coding or the like, and then framed by a predetermined transmission data forming unit (not shown) and sent to the transmission path.

As a result, the first to fifth hierarchical compressed coded data D145 to D149 and the control code D150 are decoded by the picture decoding apparatus 160 shown in FIG. In other words, the first to fifth hierarchical compressed coded data D145 to D149 are input to the decoders 161 to 165 having encoding and inverse decoding methods of the encoders 154 to 158, respectively. As a result, the inter-layer difference data D151 to D154 of the first to fourth layers respectively decoded by the decoders 161 to 164 are passed through the first to fourth adders 175 to 1 through the division control circuits 170 to 173 of the first to fourth layers, respectively. It is entered as 178.

The fifth hierarchical compressed coded data D149 is decoded by the decoder 165, and the fifth hierarchical data D155 obtained as a result is output as it is, and is input to the fourth adder circuit 178. The fourth adding circuit 178 adds the fifth layer data D155 and the interlayer difference data D154 of the fourth layer to restore the fourth layer data D159, outputs it, and sends it to the third adding circuit 177.

Similarly, the third adding circuit 177 adds the restored fourth layer data D159 and the third layer difference data D153 to restore the third layer data D158, and outputs the same to the second adding circuit 176. Send it out. Similarly, the second layer data D157 and the first layer data D156 are restored from the second and first addition circuits 176 and 175, whereby the first to fourth and fifth layer data D156 to D159, D155 are added. Is output.

The control code D150 is input to the control code analysis circuit 166. The control code analysis circuit 166 analyzes whether or not transmission stop of inter-layer difference data occurs on the basis of the input control code D150, and sends the analysis result to the division control circuits 170 to 173 as the transmission stop flag F. When the division control circuits 170 to 173 detect that the transmission stop of inter-layer difference data has occurred on the basis of the input transmission stop flag F, the division control circuits 170 to 173 substitute the inter-layer difference data of the value "0" as dummy data instead of the inter-layer difference data. Is generated and sent to the adders 175 to 178.

Accordingly, according to the block activity of the inter-layer difference data, the image encoding device 140 transmits only control data indicating the stop of transmission, without transmitting the inter-layer difference data of unnecessary blocks, thereby transmitting the control data to the control data. Based on this, hierarchical data can be reliably restored.

According to the above configuration, the block activity is determined for a predetermined block of inter-layer difference data of each layer except for the highest layer, and when the block activity is less than a predetermined threshold, the block activity corresponds to a block in the inter-layer difference data of an adjacent lower layer. A division stop flag is set as a decision flag of a plurality of lower blocks, the determination of the block activity of the plurality of lower blocks and the transmission of the plurality of lower blocks is stopped, and a decision flag for each block is transmitted together with the encoding code. In this way, an image encoding method and an image encoding apparatus are realized in which coded data of an unnecessary block is not transmitted in accordance with the block activity of inter-layer difference data, thereby reducing the code amount and improving the compression efficiency of the encoded data.

(2) Another embodiment of the first embodiment

(2-1) In the above embodiment, the control signal C1, C2, which instructs the lower layer to stop dividing when the block activity is determined by the block of inter-layer difference data, and the block activity is less than a predetermined threshold. Although the case where C3 is sent and a division stop flag is set as a determination flag of a plurality of lower blocks corresponding to a block in lower inter-layer difference data has been described, the present invention has been described. However, the present invention is not limited to this. As shown in FIG. 9, when the block activity is lower than a predetermined threshold, the control signals C1, C2, and C3 instructing to stop dividing are sent to the lower layers, and a plurality of blocks corresponding to the blocks in the differential data between the lower layers are transmitted. Once the division stop flag is set as the determination flag of the lower block of and the block activity of any block of the plurality of lower blocks is higher than or equal to a predetermined threshold, The control signals C4, C5, and C6 which have been divided into the division control circuits 151, 152 or 153 of the layer are sent out, the division stop flag is changed into a division continuation flag, and the decision flag for each block is used as an encoding code. It may be sent together.

Therefore, in order to realize this, even in the case where the block activity is determined for all interlayer difference data to the division control circuit in the image encoding apparatus described above with reference to FIG. When it is detected that the block activity is equal to or greater than the threshold, the lower division control circuit may send an instruction to change the transmission stop to the transmission continuation from the upper division control circuit.

(2-2) In the above embodiment, image data is sequentially recursively divided into a plurality of hierarchical data having a plurality of different resolutions, and each hierarchical data except the highest hierarchical data having the lowest resolution and the highest hierarchical data, and Although the case where the inter-layer difference data for a plurality of layers, which are the difference values of adjacent upper hierarchical data, has been described, the present invention is not limited to this, but the present invention is not limited to this. The same applies to the case of encoding by dividing into data. In this case, the determination of the block activity is also performed on the blocks of the hierarchical data instead of the inter-layer difference data, and the same effect as in the above embodiment can be realized.

(2-3) In the above-described embodiment, the case where the determination of the maximum value in the block and the threshold value is made as the block activity is described. However, the present invention is not limited to this, but the average value in the block as the block activity is described. , The absolute value, the standard deviation, the n sum, etc., may be used to determine the threshold value, and similar effects to those of the above embodiment can be realized by using a data frequency of data exceeding a predetermined threshold value within the block. have.

(2-4) Further, in the above embodiment, when dividing into plural layer data, the adjacent higher layer data is formed recursively by an arithmetic mean of each block of the image data or the adjacent lower layer data. Although the present invention is not limited thereto, the present invention may be recursively formed of adjacent upper layer data by a weighted average so as to take an average with a predetermined weight, and also by other techniques such as decaying. The same applies to the case where the higher layer data is formed recursively.

(2-5) In the above embodiment, the case where the block activity in the block is determined to stop the data transmission of the lower layer has been described. However, whether to stop the transmission is not limited to the block activity. Alternatively, other properties of the image data may be used, and the coding efficiency can be improved by performing adaptive block division in accordance with the properties of the image data.

(3) As described above, according to the present invention, when displaying and hierarchically encoding image data using a recursive hierarchical representation, the adaptive block corresponding to the property of the image data is divided and encoded, and the division is performed. The resulting image encoding method and image encoding apparatus capable of transmitting the resulting hierarchical encoded data and adaptively dividing the lower layer block can reduce the amount of information such as flat portions of the image.

The block activity is determined for a predetermined block of the layer data except the highest layer data having the lowest resolution, and when the block activity is less than a predetermined threshold, it is determined as a determination flag of a plurality of lower blocks corresponding to the block in the adjacent lower layer data. By setting the segmentation abort flag, stopping the determination of the block activity of the plurality of lower blocks and the transmission of the plurality of lower blocks, and transmitting the decision flag for each block together with encoding and coding the block activity of the hierarchical data. It is possible to realize an image encoding method and an image encoding apparatus which improve the compression efficiency of encoded data by reducing the amount of code by not transmitting the encoded data of unnecessary blocks in accordance with the vertices.

Also, a block activity is determined for a predetermined block of inter-layer difference data of each layer except for the highest layer, and when the block activity is less than a predetermined threshold, a plurality of lower layers corresponding to the block in the inter-layer difference data of an adjacent lower layer. By setting a segmentation stop flag as a decision flag of the block, stopping the determination of the block activity of the plurality of lower blocks and the transmission of the plurality of lower blocks, and transmitting the decision flag for each block together with the encoding code, According to the block activity of the inter-difference data, an image encoding method and an image encoding apparatus can be realized in which the code amount is reduced so as not to transmit the encoded data of an unnecessary block, thereby improving the compression efficiency of the encoded data.

Also, a block activity is determined for a predetermined block in the hierarchical data except the highest hierarchical data having the lowest resolution, and when the block activity is less than a predetermined threshold, a decision flag of a plurality of lower blocks corresponding to the block in adjacent lower hierarchical data. To set a segmentation stop flag once, to change the segmentation stop flag to a segmentation continuation flag when the block activity of a block of a plurality of sub-blocks is equal to or greater than a predetermined threshold, and to transmit a decision flag for each block with an encoding code. The image encoding method and the image, thereby improving the compression efficiency of the encoded data by reducing the amount of code by preventing the deterioration of the image quality according to the block activity of the hierarchical data, thereby determining the necessity of the block and not transmitting unnecessary encoded data. The encoding device can be realized.

Further, the block activity is determined for a predetermined block of inter-layer difference data of each layer except for the highest layers, and when the block activity is less than a predetermined threshold, a decision flag of a plurality of lower blocks corresponding to the block in the adjacent lower layer data. To set a segmentation abort flag once, to change the segmentation abort flag to a segmentation dividing flag when the block activity of a block of a plurality of sub-blocks is equal to or greater than a predetermined threshold, and transmit a decision flag for each block together with an encoding code. By preventing the deterioration of image quality according to the block activity of the inter-layer difference data, it is possible to determine the necessity of the block so as not to transmit unnecessary encoded data and to reduce the amount of code to improve the compression efficiency of the encoded data. The method and the picture coding apparatus can be realized.

[3] second embodiment

(1) The picture coding apparatus of the second embodiment

10 shows a second embodiment in which the same reference numerals are used to display corresponding parts of the sixth diagram. In this case, the division control circuits 150 to 153 of the image encoding apparatus 190 have a predetermined block in the interlayer difference data D140 to D143. Whether or not to determine a threshold value Tha of a block activity indicating whether or not a flat portion is matched for each block of the interlayer difference data D140 to D143 of each layer, and whether to transmit the corresponding block of the interlayer difference data D140 to D143. Determine the processing of

For example, when the activity in the block of the inter-layer difference data D143 of the fourth layer is A,

If is satisfied, it is determined that the image data is a block in which deterioration is hard to occur in a flat portion, and a determination flag F for not transmitting the block is set. Accordingly, the division control circuits 150 to 153 make a determination every time with respect to the threshold value Tha of the block activity for all the blocks of the inter-layer difference data D140 to D143 of each layer, and the determination flag F of whether to transmit the corresponding block is controlled. It is sent to the code generating circuit 159.

In this way, the inter-layer difference data D140 to D143 of each layer sent from the division control circuits 150 to 153 are sent to the encoders 154, 155, 156, and 157, and the fifth layer data D135 of the uppermost layer is sent to the encoder 158 as it is. The encoders 154, 155, 156, and 157 compression-code the inter-layer difference data D140 to D143 by a nonlinear encoding method suitable for encoding the differential data, and thereby generate the first to fourth hierarchical compressed coded data D145 to D148. The encoder 158 compresses and codes the fifth hierarchical data D135 by a linear encoding method suitable for encoding the image data as the average data, and the fifth hierarchical compressed coded data D149 is generated therefrom. The first to fifth hierarchical compressed coded data D145 to D149 and the control code are framed by a predetermined transmission data forming unit (not shown) and sent to the transmission path.

Accordingly, the image encoding apparatus 190 determines the block activity of the inter-layer difference data, and transmits only the control data indicating the transmission stop without transmitting unnecessary blocks, thereby controlling the control data in the image encoding apparatus 160 (FIG. 8). The hierarchical data can be reliably restored on the basis of.

According to the above configuration, the block activity is determined every time for all blocks of the inter-layer difference data of each layer except the top layer, and the processing of the inter-layer difference data in the block is selected according to the determination result. The amount of information can be controlled individually and reduced, thereby improving the compression efficiency when hierarchically encoding image data.

(2) Another embodiment of the second embodiment

(2-1) In the above embodiment, image data is sequentially recursively divided into a plurality of hierarchical data having a plurality of different resolutions, and each hierarchical data except the highest hierarchical data having the lowest resolution and the highest hierarchical data, and A case of encoding inter-layer difference data for a plurality of layers, which is a difference value of adjacent upper layer data, will be described. However, the present invention is not limited thereto, and the present invention is not limited thereto, and the image data is sequentially recursively divided into a plurality of layer data having a plurality of different resolutions. This can also be applied to the case of encoding by encoding. In this case, the determination of the block activity is also performed on the blocks of the hierarchical data instead of the inter-layer difference data, and the same effect as in the above embodiment can be realized.

(2-2) In the above embodiment, the case where determination is made between the maximum value and the threshold value in the block as the block activity is described. However, the present invention is not limited to this, but the average value and the absolute value in the block as the block activity are described. The sum, standard deviation, n multiplication, and the like may be determined for the threshold, and the same effect as in the above embodiment can be realized by using the frequency of the data exceeding the predetermined threshold in the block.

(2-3) In the above embodiment, when dividing into a plurality of hierarchical data, the case where the adjacent high hierarchical data is formed recursively from an arithmetic mean for each predetermined block of image data or adjacent low hierarchical data will be described. However, the present invention is not limited to this, and the upper layer data may be formed recursively by a weighted average taking an average with a predetermined weight, and the upper layer data may be recursively formed by other methods such as a human. It can also be applied.

(3) According to the present invention as described above, the block activity is determined every time for all blocks of the hierarchical data except the highest hierarchical data having the lowest resolution, and the processing of the hierarchical data in the block is selected according to the determination result. It is possible to realize an image encoding method and apparatus which can individually control the amount of generated information in the interior and reduce it, thereby improving the compression efficiency when hierarchically encoding image data.

In addition, the block activity is determined every time for all blocks of the inter-layer difference data of each layer except for the highest layer, and the processing of the generated information in the block is individually controlled by selecting processing of the inter-layer difference data in the block according to the determination result. It is possible to realize an image encoding method and apparatus that can be reduced in size, thereby improving the compression efficiency when hierarchically encoding image data.

[4] third embodiment

(1) The picture coding apparatus of the third embodiment

11 is a generation information amount control unit which displays the image encoding device 40 of the third embodiment and controls the generation information amount in the hierarchical encoding unit 40A and hierarchical encoding unit 40A for hierarchically encoding and outputting input image data D31 to achieve a target value. It consists of 40B.

The hierarchical encoding encoder section 40A is composed of a data delay memory (not shown) and an encoder. Among them, the memory is provided at the input terminal in order to delay the data so that the encoding process is not executed until the optimum control value is determined in the generation information amount control unit 40B.

On the other hand, the generation information amount control unit 40B inputs the input image data to determine a threshold TH suitable for the data to be processed, and transmits an optimum control value determined by the hierarchical encoding unit 40A to efficiently encode the input image data to the encoder. . This is a configuration of so-called feed forward type buffering. This configuration makes it possible to eliminate time delays caused by accurate generation information control and feed forward buffering.

(2) Hierarchical Coding Encoder 40A

(2-1) Block structure

The hierarchical encoding encoder 40A has the configuration shown in FIG. 12. In this example, the hierarchical encoding encoder 40A is divided into five hierarchies.

First, input image data D31 is input to the first difference circuit 41 and the first averaging circuit 42. The first averaging circuit 42 generates the second hierarchical data D32 by the four pixel average of the input image data D31 (that is, the first hierarchical data (lowest hierarchical data)). In the case of this embodiment, the first averaging circuit 42 uses the pixels X1 (2) of the second hierarchical data D2 from the pixels X1 (1) to X4 (1) of the input image data D31 as shown in Figs. 15 (D) and (E). )

The pixels X2 (2) to X4 (2) adjacent to the pixel X1 (2) of the second hierarchical data D32 are similarly generated by obtaining the four-pixel average of the first hierarchical data D31.

The second hierarchical data D32 is input to the second difference circuit 43 and the second averaging circuit 44, and the second averaging circuit 44 generates the third hierarchical data D33 by the four pixel average of the second hierarchical data D32. For example, the pixel X1 (3) of the third hierarchical data D33 is generated from the pixels X1 (2) to X4 (2) of the second hierarchical data D32 shown in FIGS. 15C and 15D, and the pixel X1 Similarly, pixels X2 (3) to X4 (3) adjacent to (3) are also generated by the four pixel average of the second hierarchical data D32.

The third hierarchical data D33 is input to the third difference circuit 45 and the third averaging circuit 46, and the third averaging circuit 46 uses the fourth pixel average of the third hierarchical data D33 to obtain the fifteenth (B ), And the fourth hierarchical data D34 composed of the pixels X1 (4) to X4 (4) is generated as shown in (C) and (C).

The fourth hierarchical data D34 is input to the fourth difference circuit 47 and the fourth averaging circuit 48, and the fourth averaging circuit 48 receives the fifth hierarchical data D35, which is the highest layer from the four pixel average of the fourth hierarchical data D34. Create That is, as in the fifteenth (A) and (B), the pixel X1 (5) of the fifth hierarchical data D35 is generated by averaging four pixels X1 (4) to X4 (4) of the fourth hierarchical data D34.

Here, the block size of the first to fifth hierarchical data D31 to D35 is that if the block size of the first hierarchical data D31 which is the lowest layer is 1 line x 1 pixel, the second hierarchical data D32 is 1/2 line x 1/2. Pixel, 3rd layer data D33 is 1/2 line x 1/4 pixel, 4th layer data D34 is 1/8 line x 1/8 pixel, 5th layer data D35 which is the highest layer data is 1/16 line x 1 / 16 pixels.

The hierarchical encoding encoder 40A repeats the recursive processing in order from the highest hierarchical data (that is, the fifth hierarchical data D35) of the first to fifth hierarchical data D31 to D35 to determine the difference between two adjacent hierarchical data. Obtained from the difference circuits 41, 43, 45, and 47, only the difference data is compressed and coded by the encoders 51 to 55. Accordingly, the hierarchical encoding encoder 40A compresses the amount of information transmitted to the transmission path. In addition, the hierarchical encoding encoder 40A reduces the amount of transmission data by subtracting one pixel among the lower hierarchical four pixels corresponding to the upper hierarchical one pixel by the encoders 51 to 54, as described above for the expression (2).

In order to maintain such a compression condition optimally, the hierarchical encoding encoder 40A decodes the transmission data D51 to D55 obtained for each layer by the decoders 56 to 59.

The decoder 59 corresponding to the highest layer among them decodes the decoded data D48 corresponding to the fifth hierarchical data D35 coded and encoded in the encoder 55 from the transmission data D55, and outputs it to the differential circuit 47 of the fourth layer.

In contrast, the other decoders 56 to 58 switch decoding operations based on flags indicating whether or not the division / non-division processing is performed, respectively. In other words, in the case of division processing, higher layer data (i.e., fourth, third and second layer data) is decoded by the decoding process from the difference data transmitted as the transmission data D52 to D54, and the difference of the third layer is decoded. Output to the circuit 45, the differential circuit 43 of the second layer, and the first layer data 41, respectively.

As a result, difference data D41, D42, D43, and D44 for adjacent layers are obtained from the difference circuits 41, 43, 45, and 47.

In practice, the decoders 58, 57, 56 are configured as in FIG. The decoder 58 is described here for the sake of simplicity. The decoder 58 receives the fourth layer compressed coded data D54 in the decoding circuit 58A and decodes it. As a result, the output values of X1 (4)-X1 (5), X2 (4)-X1 (5), and X3 (4)-X1 (5) shown in FIG. 15 are obtained from the decoding circuit 58A, for example. The output value is added to the reconstruction data D48 in the following addition circuit 58B, thereby obtaining output values of X1 (4), X2 (4), and X3 (4). The difference value generation circuit 58C generates the untransmitted pixel X4 (4) by performing calculation based on equation (4) using X1 (4), X2 (4), X3 (4) and X1 (5). Therefore, from the subsequent synthesis circuit 58D, the differential layered fourth layer data X1 (4), X2 (4), X3 (4), and X4 (4) are generated, which are provided to the differential circuit 45.

The encoders 51 to 54 corresponding to each layer input the difference data D41, D42, D43, D44 or the fifth layer data D35 obtained by the difference circuit 41, 43, 45, 47 or the averaging circuit 48, and for each block. Threshold determination and division selection processing are performed on the obtained activities.

At this time, the encoders 51 to 54 compressively encode the difference data obtained between the layers as they are when the processing target is a divided block, and at the same time, add a division determination flag for each block and transmit it.

On the other hand, when the processing targets are undivided blocks, the encoders 51 to 54 replace the blocks with higher layer data at the receiving side and exclude them from the coding targets. Thus, even in that case, the division decision flag for each block is added and transmitted.

The first to fifth hierarchical compressed coded data D51 to D55 output from these five sets of encoders 51 to 55 are framed by a predetermined transmission data forming unit (not shown) and sent to the transmission path.

Here, the encoders 51, 52, 53 and 54 are configured as in FIG. 14 shows the configuration of encoders 52 and 53 for simplicity.

In other words, the difference data D42 and D43 are input to the encoding circuits 52A and 53A of the encoders 52 and 53, respectively. The difference data D42 and D43 are input to the activity detection circuits 52C and 53C of the division controllers 52B and 53B, respectively. The activity detection circuits 52C and 53C detect the activity for each predetermined block of the difference data D42 and D43, and provide the detection result obtained to the subsequent threshold determination circuits 52D and 53D. The threshold determination circuits 52D and 53D compare the activity detection result for each block with the threshold data D57 from the generation information amount control unit 40B, and send the determination result obtained to the coding circuits 52A and 53A. The encoding circuits 52A and 53A perform compression encoding on a high activity block and transmit the same based on the threshold determination result, but do not transmit a low activity block.

(2-2) processing

Next, specific signal processing by the hierarchical encoding encoder 40A will be described.

First, consider a case in which processing for inter-layer differences is selected by the block activity based on the inter-layer differences. It is assumed that each block is composed of 2 lines x 2 pixels.

Here, the data value of each pixel is assumed to be X, and the hierarchical layer of the data value X is indicated by additional characters. In other words, when the upper layer data is Xi + 1 (0), the adjacent lower layer data is Xi (j) (j = 0 to 3). The difference code value between hierarchies is ΔXi (j) (j = 0-3), and the hierarchical encoding encoder 40A compresses and encodes the difference code value.

In each layer, the compression encoding processing by the encoders 51 to 55 compares the block activity P obtained for each block with the threshold data D57, and selects the processing based on the comparison result.

In other words, when the block activity P is equal to or greater than the threshold TH, the sublayer is sequentially processed. If the block activity P is less than the threshold TH, the partitioning process for the lower layer is stopped.

As a result, only the upper hierarchical data is transmitted to the area where the block activity P is low, so that the amount of transmission information can be reduced.

Further, the image data decoding apparatus for narrowing the transmission path and using the higher layer data among the sequentially transmitted transmission data restores the lower layer data to the higher layer data in a region having low block activity. On the other hand, in an area with high block activity, data is restored by adding the differential decoding values between the layers and the upper layer data.

A 1-bit decision flag is introduced into this division or non-division decision result. This flag makes it possible to instruct the determination result for each block.

This decision flag is necessary for one bit per block of each layer, but is effective when considering the image quality.

Therefore, in this embodiment, the hierarchical coding scheme does not reflect the judgment flag in subsequent judgments at lower layers. This decision flag is encoded by run-length encoding or the like and transmitted together with the encoding code.

(3) Generation information amount control part 40B

(3-1) Block structure

On the other hand, the generation information amount control unit 40B is configured as shown in FIG.

Since the generated information amount control unit 40B can encode and process image data efficiently without deteriorating the picture quality, the combination encoding unit 40A sets a combination of thresholds TH1 to TH4 for each layer serving as a selection criterion for division / undivision. Then, it is output as the threshold data D57 to the hierarchical encoding encoder 40A.

The generation information amount control unit 40B averages the input image data D31 1/4 through the average value circuits 42, 44, 46, and 48 in order to generate five layers of image data having different resolutions.

Subsequently, the difference between the hierarchical image data D32, D33, D34, and D35 on one layer and the image data D31, D32, D33, and D34 on each layer is calculated so as to obtain the amount of information for each layer of image data transmitted as difference data. Obtained from circuits 61, 62, 53 and 64.

The difference data output from each of these difference circuits 61, 62, 63, and 64 can be defined as difference data of each layer obtained by the layer processing in the layer encoding encoder 40A.

The activity detection circuits 65, 66, 67, and 68 correspond to image data of the first to fourth layers, respectively, and obtain block activities for each block of each layer and register them in the corresponding frequency distribution tables 69 to 72. .

Here, in the generation process of the frequency distribution table, in order to accurately grasp the amount of data transmitted from the encoder, three pixels that are actually transmitted by the encoder are used among the lower layer 4 pixels corresponding to the upper layer 1 pixel.

The image data of the fifth hierarchical layer is directly transmitted as the hierarchical hierarchical data instead of the difference data, so that the dynamic range for each block is registered in the frequency distribution table 73 as it is.

The control unit 74 is connected to these five frequency distributions 69 to 73 in a two-way signal channel to combine the threshold values TH1 to TH4 of the block activities that serve as a criterion for determining whether to divide or undivid the lower layer. Is stored in the ROM.

The control unit 74 provides these combinations to the frequency distribution tables 69 to 73, reads out the amount of occurrence information generated for each threshold, and calculates the total amount of occurrence information as a whole based on the total amount of occurrence information. The threshold value obtained by obtaining the optimum threshold value until the total generated information amount reaches the target value is provided to the hierarchical encoding encoder 40A as control data.

In addition, the control unit 74 can adjust the control data provided to the hierarchical encoder 40A in consideration of the nature of the image signal data and the visual characteristics of the human for each hierarchical layer and provide an optimum threshold value. As a result, the subjective picture quality is improved with respect to the picture quality reproduced on the receiving side.

(3-2) Frequency distribution table

Here, the frequency distribution tables 69 to 73 for controlling the amount of information will be described.

17A to 17E show a frequency distribution table of block activities obtained for the highest hierarchical data (the fifth hierarchical data) to the lowest hierarchical data (the first hierarchical data), respectively. As to the frequency distribution table for the fifth layer shown in FIG. 17A, the frequency distribution table based on the dynamic range is generated because the target data is not differential data. For example, when compression processing by PCM coding is performed on the fifth layer data D35, the dynamic range provided for each block is registered as data, and ADRC (Adaptive Dynamic Range Coding (USP-4703352)) is applied as the compression processing method. If so, the DR of the ADRC block is registered.

On the other hand, in another frequency distribution table 69-72, a block having a block activity having a threshold value of TH1, TH2, TH3, and TH4 or more given to each frequency distribution table becomes a division target block.

Therefore, the amount of generated information can be calculated by calculating the number of blocks having a block activity above a threshold in each layer.

Next, a calculation example of the generation information amount will be described.

Here, when the number of blocks to be N1 in the first layer and the number of blocks to be divided whose block activity is larger than the threshold TH1 are N1 ', and the number of quantization bits is Q1 at this time, the amount of information generated I1 in the first layer is Is the following formula

Can be provided by

In the equation (7), the number of bits in the first term is quadrupled because each block is divided into two lines by two pixels in this example. In the structure of claim 1, 3/4 times means that the upper hierarchical value is generated from an average value of lower hierarchical values. This is because it reflects the property that the pixel value is to be restored.

In the second term, the addition of N1 to the number of blocks in the first hierarchical layer indicates that transmission is performed by adding one bit for each block as a division determination flag.

Similarly, for the second, third, and fourth layers, the number of blocks in each layer is N2, N3, N4, and the number of blocks to be divided whose block activity is larger than the thresholds TH2, TH3, TH4 is N2 ', If N3 'and N4' are set and the number of quantization bits is Q2, Q3, and Q4, the amount of information Ik (k = 2, 3, 4) generated in each layer is represented by the following equation.

May be provided by

If the occurrence information amounts I1 to I4 for the first to fourth layers and the generation information amount I5 for the fifth layer are used, the total amount of generated information I generated by the encoding processing of the hierarchical encoding encoder 40A is given by the following equation.

As described above, it can be obtained as the sum of the amount of information generated for each layer.

(3-3) processing

The generation information amount control unit 40B inputs the input image data D31 in the same manner as the hierarchical encoding encoder 40A. The averaged circuit 42 obtains an average value for every 2 lines x 2 pixels, and reduces the number of pixels to 1/4 to reduce the resolution. . Subsequently, the hierarchical data D32 is similarly passed through the averaging circuits 43, 46, and 48, and the number of pixels is reduced to 1/4, respectively, to reduce the resolution.

The generation information amount control unit 40B thus provides hierarchical data D35 of the highest (that is, the lowest resolution) among the plurality of resolution image data to the frequency distribution table 73, and the frequency of the block activity P of each block in the fifth hierarchical data D35. Register. This is the frequency measurement of data corresponding to the compression process performed by the hierarchical encoding encoder 40A. For example, when compression processing is performed under PCM code for the fifth layer data 35, the dynamic range provided for each block is registered as data, and ADRC (Adaptive Dynamic Range Coding (USP-4703352)) is applied as the compression processing method. In this case, the DR of the ADRC block is registered.

Next, the difference data D64 is obtained from the difference between the fourth layer data D34 and the fifth layer data D35. The activity detection circuit 68 detects the activity with respect to the difference data D64, and registers it in the frequency distribution table 72 as the activity data D68.

Similarly, the block activity P of each block obtained for each of the lower hierarchical data D33, D32, and D31 is sequentially registered as the activity data D67, D66, and D65 as the activity data D67, D66, and D65.

The control unit 74 sequentially reads, from the ROM table shown in Fig. 18, the combinations for the thresholds TH1, TH2, and TH4 for the division / non-division setting set for each layer from the low-numbered pair QNO1. The block frequency with large block activity P for each threshold TH1, TH2, and TH4 is then read from the frequency distribution tables 69 to 73 for each layer and for each threshold for each layer. The amount of generated information is detected.

The control unit 74 integrates the amount of occurrence information obtained for the frequency distribution tables 69 to 73 of each layer, and calculates the total amount of occurrence information to be generated as a result of encoding in the hierarchical encoder 40A. The control unit 74 compares this generated information amount with the target value, and when the difference with the target value is large, moves to a set of thresholds TH1, TH2, and --- TH4 of the next number QNO2 in order to obtain a combination of threshold values that satisfy the target value.

Thereafter, the above process is repeated until the total amount of generated information reaches the target value, and a set of thresholds TH1, TH2, and --TH4 at which the total amount of divergence closest to the target value is obtained is obtained, and this is transferred to the hierarchical encoder 40A as the threshold data D57. Output

According to the above configuration, hierarchical coding having a plurality of resolutions can be easily realized. In addition, it is possible to realize encoding in which the total amount of generated information of the transmission image data encoded and output from the hierarchical encoding encoder 40A almost matches the target value and the compression efficiency is not lowered. In addition, hierarchical coding with low image quality deterioration can be realized. Further, management of the amount of information generated in hierarchical encoding can be made easier than in the past.

(4) Another embodiment of the third embodiment

(4-1) In the above embodiment, the case where the block activity P is determined as the maximum value of the decoded data and the lower layer data and the difference value obtained for the upper layer with respect to each block has been described. Instead, the determination may be made based on the mean error, the absolute value, the standard deviation, the n sum, and the data frequency above the threshold.

(4-2) In the above embodiment, the case where the frequency distribution table obtained for each layer is used as it is is described. However, the present invention is not limited to this, but the frequency distribution table of the integrated type is prepared from the frequency distribution table and used to calculate the generation information amount. You may also do it.

That is, when the block activity is registered and the frequency distribution table is obtained as shown in FIG. 19, the integration operation is performed with a lower value than the frequency corresponding to the maximum value of the block activity, and each result is integrated as shown in FIG. 20. Register at

When this process is expressed by a formula, k is the block activity value (k = 0 to the maximum value), and N (·) is the block frequency at each block activity value.

It becomes

The transplantation means reading the block count of the block activity value address, and writing the result of the addition to the integrated value up to the higher block activity value in the block activity value address.

In the integrated frequency distribution table (Fig. 20) obtained from the result, the block frequency sum of the oblique portions in Fig. 19 corresponds to the threshold TH coordinate data I. The integrated frequency distribution table eliminates the need to calculate the block frequency sum of the oblique portion (FIG. 19) each time the threshold TH is deflected.

That is, after generating a frequency distribution table for each layer, the cumulative addition value is calculated for the block counts from the upper level of the block activity to the value of each block activity, and each cumulative addition value is written to an address corresponding to each block activity value. By creating an integrated frequency distribution, the frequency corresponding to each block activity becomes an integrated value of block frequencies having a value equal to or greater than the block activity.

In this way, when the integrated frequency distribution table is generated in advance, it is not necessary to calculate the block frequency integrated value corresponding to each threshold value, and the calculation of the block frequency integrated value is possible only by reading the threshold address of the memory, and the time required for calculation is calculated. We can cut drastically.

Here, in the actual threshold processing, it is difficult to use a large decision threshold in order to avoid deterioration in image quality. Therefore, the frequency distribution table which clipped the block activity value may be created.

That is, as shown in FIG. 21, when the block activity value is clipped to the LMT, the block counts of the LMT or more are registered in the entire LMT in the frequency distribution table. As a result, as in the 21st degree, the block frequency in the LMT becomes large. The block count to be calculated here is in the oblique line.

The integrated frequency distribution table for this frequency distribution table is shown in FIG. In this case, the integration operation of the above expression (10) is performed in the section from the block activity value LMT to 0, not the maximum value of the block activity value. The block frequency sum to be calculated is the integrated block frequency I of the coordinates of the threshold TH. Thus, the same results as in the case shown in FIG. 20 are obtained.

As a result, the time required to generate the integrated frequency distribution table can be shortened, and the frequency distribution table memory can be further miniaturized.

Therefore, when the clipped value LMT is set, a method of changing the clipped value LMT for each layer as a first method and a method of fixing the clipped value LMT in the entire layer as a second method are considered. The first method is used in the case where the difference distribution between the layers of each layer is clearly different, and the second method is used when the difference distribution between the layers of each layer is not large.

In the above embodiment, the case where PCM encoding of image data in the encoder is explained. However, the present invention is not limited to this, and other coding schemes such as orthogonal coding schemes may be applied.

In the above embodiment, a case is described in which a plurality of combinations are stored in the POM for the threshold values of the frequency distribution table obtained for each layer, and a combination of the threshold values close to the target value is generated, but the present invention is not limited thereto. Each layer may be set independently.

In the above embodiment, a case is described in which the lowest hierarchical data is averaged by 2 lines x 2 pixels to obtain image data of an upper hierarchical layer. However, the present invention is not limited thereto, and the average may be obtained by other combinations.

(5) As described above, according to the present invention, when image data is sequentially recursively divided into a plurality of hierarchical data having a plurality of different resolutions, a predetermined block of hierarchical data except for the highest hierarchical data having the lowest resolution is blocked. By determining the activity and setting it from the frequency distribution of the blocks with respect to the lower hierarchical data, the hierarchical coding method of the image data without deterioration of the compression efficiency can be easily realized.

[5] fourth embodiment

(1) The picture coding apparatus of the fourth embodiment

The picture coding apparatus 80 of the fourth embodiment has a schematic structure similar to that of the third embodiment (figure 11), as shown in FIG. 23, and hierarchically coded encoder section 80A for hierarchically coding the input image data D31. And the generation information amount control unit 80B which controls the generation information amount to achieve the target value in the hierarchical encoding encoder unit 80A.

The hierarchical encoding encoder 80A is composed of a data delay memory (not shown) and an encoder. Among them, a memory is provided at the input terminal in the generation information amount control unit 80B so as to delay the data so that encoder processing is not executed until the optimum control value is determined.

On the other hand, the generation information amount control unit 80B is configured to input the input image data D31 to determine a threshold TH suitable for the data to be processed, and the optimum control value determined by the hierarchical encoding encoder unit 80A to efficiently encode the input image data D31 as an encoder. To send. This is a configuration of so-called feed forward type buffering. This configuration makes it possible to eliminate the time delay caused by the precise generation information control and the feed forward buffering.

Here, the division process in the lower layer is selected by the block activity defined based on the inter-layer difference value. That is, higher layer data is constructed from 4 pixels of 2x2 of a lower layer, and a block is defined.

In this case, the activity is expressed by the maximum value, average value, absolute value, standard deviation, or n sum of the interlayer difference data D41 to D44 in a predetermined block when the lower layer data area corresponding to the upper layer data is defined as a "block". Correlation. In other words, when the activity is low, the block becomes a flat block.

In other words, if the upper layer data is XO (i + 1) and the lower layer data is Xj (i), the inter-layer difference code value? Xj (i) = XO (i + 1)-Xj (i). However, j = 0-3. If the block activity determination function is G (·), then the block activity ACT = G (ΔXj (i)).

If the FLG (0: stop division, I: continue division), the division of the lower layer is stopped if FLG = 0, and the division of the lower layer is executed if ACT≥ threshold TH and FLG = 1. If ACT <threshold TH and FLG = 1, the partitioning of the lower layer is stopped.

After completion of the division decision in that layer, the division decision result is defined as the decision flag FLG, and then transferred to the next lower layer. Thus, in the case of FLG = 0, division in lower layer is not performed.

(2) hierarchical encoding encoder

The hierarchical encoding encoder 80A has the configuration shown in FIG. 24 and has the same configuration as described in FIGS. 12 and 13 except that the encoders 51 to 54 are configured as in FIG.

In this case, the encoders 54, 53, and 52 transmit the threshold determination result information J1, J2, J3 used for dividing or non-dividing the blocks, respectively, to the encoders 53, 52, 51 of the adjacent lower layer. As a result, the hierarchical encoding encoder 80A stops dividing all the blocks in the subsequent lower hierarchies with respect to a block in which discontinuous division has been stopped.

In practice, the encoders 51 to 54 are configured as in FIG. 25 shows the configuration of encoders 52 and 53 for simplicity.

The encoder 53 inputs the difference data D43 to the activity detection circuit 53C of the encoding circuit 53A and the division controller 53B. The activity detection circuit 53C detects the activity for each predetermined block of the difference data D43 and provides the detection result obtained by the subsequent threshold determination circuit 53D. The threshold determination circuit 53D compares the activity detection result for each block with the threshold data D57, and transmits the determination result obtained as the threshold determination result information J2 to the encoding circuit 53A and the encoder 52 of the adjacent lower layer. The encoding circuit 53A compresses and encodes the high block of the activity based on the threshold determination result information J2, and does not transmit the block with the low activity.

In this case, the activity detection circuit 53C and the threshold determination circuit 53D receive the threshold determination result information J1 outputted from the encoder 54 of the adjacent upper layer and indicate that the threshold determination result information J1 divides the block. Executes the vertex detection and threshold determination results. On the other hand, when the threshold determination result information J1 indicates the non-division of the block, activity detection and threshold determination are not performed on the block corresponding thereto, and the threshold determination circuit 53D displays the non-division of the block. Output the result information J2.

Similarly, in the encoder 52, when the activity detection circuit 52C and the threshold determination circuit 52D receive the threshold determination result information J2 indicating the division of the block from the encoder 53 of the adjacent upper layer, the activity detection and threshold determination for the corresponding block are executed. On the other hand, when the threshold determination result information J2 indicating the non-division of the block is received, the activity detection and threshold determination are not performed, and the threshold determination result information J3 indicating the non-division of the block is output from the threshold determination circuit 52D. .

In this way, in the hierarchical encoding encoder 80A, once a block non-division determination result is obtained, the block corresponding to the block is not divided (i.e., not encoded) in the subsequent lower layers.

(3) occurrence information amount control unit

The generation information amount control unit 80B is configured as shown in FIG.

The generation information amount control unit 80B sequentially averages the input image data D31 through the average circuits 42, 44, 46, and 48 in order to generate five layers of image data having different resolutions.

Subsequently, the difference between the hierarchical image data D32, D33, D34, and D35 on one layer and the image data D31, D32, D33, and D34 on each layer is determined in order to obtain the amount of occurrence information for each layer of the image data transmitted as difference data. Obtained from the differential circuits 61, 62, 53 and 64.

The difference data output from each of the difference circuits 61, 62, 63, and 64 can be defined as the difference data of each layer obtained by the layer processing in the layer encoding encoder 80A.

The activity detection circuits 65, 66, 67, and 68 correspond to the image data of the first to fourth layers, respectively, and obtain the activity for each block of each layer and register them in the corresponding frequency distribution tables 69 to 72. have.

Here, in the process of generating the frequency distribution table, in order to accurately grasp the transmission data amount of the encoder, three pixels that are actually the transmission targets by the encoder are used among the lower layer 4 pixels corresponding to the upper layer 1 pixel.

The image data of the fifth hierarchical layer is directly transmitted as the hierarchical hierarchical data instead of the difference data, so that the dynamic range for each block is registered in the frequency distribution table 73 as it is.

This measures the frequency of data corresponding to the compression process performed in the encoder part 80A. For example, when compression processing by PCM encoding is performed on the fifth layer data D35, the dynamic range provided for each block is registered as data, and ADRC (Adaptive Dynamic Range Coding (USP-4703352)) is applied as the compression processing method. If so, the DR of the ADRC block is registered.

Next, difference data D64 from the fourth layer data D34 and the fifth layer data D35 is generated. The block activity is detected by the activity detection circuit 68 with respect to this difference data D64. The block activity D68 detected here is registered in the frequency distribution table 72.

The difference data D63 is generated from the third layer data D33 and the fourth layer data D34. The block activity is detected in the activity detection circuit 67 with respect to the difference data D63. The block activity D67 detected here is registered in the frequency distribution table 71. At this time, the third layer performs block division determination on only the blocks that have received the block division continued determination in the threshold determination result in the fourth layer.

Therefore, the frequency distribution table 71 becomes a frequency distribution table indicating the number of blocks whose coordinates are determined by two variables, the block activity D68 in the fourth layer and the block activity D67 in the third layer.

The difference data D62 is generated from the second layer data D32 and the third layer data D33, and the block activity D66 is output from the activity detection circuit 66. The detected block activity D66 is registered in the frequency distribution table 70. In the second layer, block division determination is performed on only blocks that have been subjected to block division continuing determination in the fourth and third layers.

Therefore, the frequency distribution table 70 becomes a block frequency distribution table in which coordinates are determined from three variables of block activity D68 in the fourth layer, block activity D67 in the third layer, and block activity D66 in the second layer.

Finally, the difference data D61 is generated from the first layer data D31 and the second layer data D32 and the block activity D65 is output from the activity detection circuit 65. The detected block activity D65 is registered in the frequency distribution table 69. In the first layer, block division determination is performed on only blocks that have been subjected to block division continuation determination in the fourth layer, the third layer, and the second layer.

Thus, the frequency distribution table 69 consists of four variables: block activity D68 in the fourth layer, block activity D67 in the third layer, block activity D66 in the second layer, and block activity D65 in the first layer. .

The amount of occurrence information is controlled by using the frequency distribution tables 69 to 73 generated accordingly. Each frequency distribution table and the control section 74 at the rear end are connected by bidirectional signal channels D69-D73.

In the controller 74, a threshold for the angle distribution table is first transmitted to each frequency distribution table. In each frequency distribution table, the generation information amount corresponding to a threshold value is detected. In the angular number distribution table, the amount of information generated is transmitted as a signal to the controller 74 via D69-D73.

The control unit 74 integrates the amount of occurrence information in each received frequency distribution table, and calculates the total amount of occurrence information to be controlled. The total value of occurrence information is compared with the target value, and the threshold value is changed to satisfy the target value from the comparison result.

The updated threshold value is transmitted from the controller 74 to the angle distribution table via signals D69-D73. Incidentally, the occurrence information amount corresponding to this is transmitted to the control unit 74 again.

The above process is repeated, and the control result D57 which finally achieved the target value is determined. The determined generation information amount control value D57 is transmitted to the hierarchical encoding encoder 80A.

During this information amount control process, data to be controlled is held by the memory M1 included in the encoder unit 80A. By using such a configuration of feed forward buffering, a threshold suitable for the target data can be determined, and efficient encoding can be realized.

Here, the frequency distribution tables 69 to 73 for controlling the amount of information will be described.

27A to 27E show a frequency distribution table of block activities obtained for the highest hierarchical data (the fifth hierarchical data) to the lowest hierarchical data (the first hierarchical data), respectively. Here, with respect to the frequency distribution table for the fifth hierarchy shown in FIG. 27A, the frequency distribution table based on the dynamic range is generated because the target data is not the difference data. For example, when the PCM encoding is applied, the dynamic range for the coded block is registered.

On the other hand, in the other frequency distribution tables 69 to 72, the target data is differential data, and blocks having block activities of thresholds TH1, TH2, TH3, and TH4 or more given to each frequency distribution table are the target blocks to be divided.

Therefore, the amount of generated information can be calculated by calculating the number of blocks having a block activity above a threshold in each layer.

Next, an example of calculating the generation information amount will be described. In order to calculate the amount of occurrence information, it is necessary to calculate the number of blocks equal to or greater than the division determination threshold in each layer. However, in the hierarchical encoding by the decision flag propagating method, which is the target in this embodiment, the generation information amount control is performed in the upper layer. It is necessary to remove the block that has received the division stop determination from the determination target in the lower layer.

In each layer, a threshold for the block activity is introduced to perform the division decision.

Here, if the sum of the number of pixels in the division block in the first layer is M1, the number of quantization bits in the first layer data is Q1, and the number of determination flag bits in the first layer is N1, the amount of information I1 generated in the first layer is N1. food

Can be obtained by

In the equation (11), the number of bits in the first term is four times because in this example, each block is divided into two lines x two pixels. In the structure of claim 1, 3/4 times the fourth non-transmitted pixel of the lower layer by an arithmetic expression using the upper layer value and the lower layer value transmitted 3 pixels in the structure in which the upper layer value is generated from the average value of the lower layer values. This is due to the nature of the restoration.

4. The addition of N1 to the number of blocks in the first layer according to claim 2 indicates that transmission is performed by adding one bit for each block as a division determination flag.

Similarly, for the second, third, and fourth layers, the sum of the number of pixels in the divided blocks in each layer is M2, M3, M4, and the number of quantization bits in each layer is Q2, Q3, Q4, in each layer. When the number of determination flag bits of N2, N3 and N4 is N, the amount of information _Ik (k = 2, 3, 4) generated in each layer is

Is given by

When the occurrence information amounts I1 to I4 for the first to fourth layers and the generation information amount I5 for the fifth layer are used, the total generated information amount I generated by the encoding processing of the layer encoding encoder 80A is expressed by the following equation.

As described above, the sum is generated as the sum of the amount of information generated for each layer.

Here, the number of bits of the determination flag is added to the amount of information generated in each layer, but the information amount of this flag is the same as the number of blocks for which division processing is performed in the upper layer. In other words, a block in which division processing is stopped in an upper layer is excluded from a division determination target in a lower layer. The spatial position of each block can be specified in each layer by the history of decision flags from higher layers.

Here, each frequency distribution table is demonstrated.

As described above, since the frequency distribution table of the highest hierarchical data depends on the compression method, it is not always determined. However, the amount of information generated can be controlled by means such as a frequency distribution table.

Next, with respect to the fourth layer data, the block frequency for the block activity ACT4 is registered. By using the fourth hierarchical frequency distribution table of FIG. 28B for the fifth hierarchical frequency distribution table shown in FIG. 28A, the amount of occurrence information for the threshold TH4 can be easily calculated.

Since blocks equal to or larger than the threshold TH4 are to be divided, the amount of information generated in the fourth layer is calculated by calculating the sum of the number of blocks equal to or greater than the threshold.

Next, for example, FIG. 29 of the frequency distribution table of the third hierarchy is shown. In the determination flag delivery method, a block that has received the division stop determination in the upper layer is excluded from the determination object.

Here, a frequency distribution table defined by two variables, the third layer block activity ACT3 and the fourth layer block activity ACT4, is introduced.

In other words, the number of blocks equal to or greater than the threshold TH4 of the fourth layer is determined.

This operation calculates the amount of information generated in the third layer that satisfies the above conditions by calculating the block counts of the threshold TH4 or more on the ACT4 axis and the threshold TH3 or more on the ACT3 axis in the frequency distribution table of FIG.

Next, FIG. 30 shows an example of the frequency distribution table of the second hierarchy and the first hierarchy.

A frequency distribution table defined by a multivariate is generated in the same manner as the third hierarchical frequency distribution table.

In the second layer, blocks defined by the block activities ACT2, ACT3, and ACT4 of the second, third, and fourth layers are registered in the frequency distribution table. This state is shown in FIG. 30A.

In the case of the second layer, the amount of information generated in the second layer is calculated by calculating the block count of the threshold TH4 or more on the ACT4 axis, the threshold TH3 or more on the ACT3 axis, and the threshold TH2 or more on the ACT2 axis.

In the first layer, blocks defined by the block activities ACT1, ACT2, ACT3, and ACT4 of the first layer, the second layer, the third layer, and the fourth layer are registered in the frequency distribution table. It shows in such FIG. 30 (B).

In the case of the first layer, the amount of information generated in the first layer is calculated by calculating the block count of the threshold TH4 or more on the ACT4 axis, the threshold TH3 or more on the ACT3 axis and the threshold TH2 or more on the ACT2 axis.

By using the above five types of frequency distribution tables, it is possible to calculate the amount of occurrence information for the threshold value and to perform control to match the target information amount.

Here, there is a method of changing the threshold value of each layer used to control the amount of occurrence information independently for each layer.

For example, there is a method of setting a preliminary target information amount for each layer and controlling the threshold value independently for each layer to conform to the target information amount.

As another method, a method for simplifying control is also considered by preparing a combination of thresholds of each layer in advance and applying the threshold combinations according to the control order.

Here, in the generation information amount control method using the frequency distribution table in each layer, an optimum control value is detected by calculating the block count of a threshold value above each threshold while taking into account the division decision result of a higher layer in each layer. .

In order to speed up the calculation time of the block frequency above this threshold, the frequency distribution table in which the block frequency is registered can be reconstructed into a truncated frequency distribution table.

An example of this integrated frequency distribution table is shown in FIG. That is, as a result of registering the block activity, the frequency distribution table example shown in FIG. 31 is obtained. In this case, for simplicity, the block activity shows an example of one variable. In the frequency distribution table, it becomes the same as that of the fourth layer.

The integrated frequency distribution table starts from the block frequency corresponding to the maximum value of the block activities in the frequency distribution table of FIG. 31, performs the integration operation with the block frequency corresponding to the smaller block activity value, and stores each integration result in the frequency distribution table. Re-register.

If this process is expressed as a formula,

Can be displayed as SUM (·) denotes the integrated block frequency, N (·) denotes the block frequency in the frequency distribution table, act denotes the block activity variable in the integrated frequency distribution table, and ACT denotes the block in the frequency distribution table. Indicate activity variables, where n represents the variable maximum in the frequency distribution table.

The expression (14) means processing of reading the block frequency of the block activity value address and adding the result of the addition to the integrated value up to the higher block activity value to the block activity value address.

As a result, an integrated frequency distribution table shown in FIG. 32 is obtained. In this integrated frequency distribution table, the block frequency sum of the oblique portions in FIG. 31 corresponds to the threshold TH coordinate data I. FIG. Since the threshold value TH is changed by this integrated frequency distribution table, it is not necessary to calculate the block frequency sum of the oblique portions of FIG. 31 each time. That is, the calculation of the block frequency sum is realized by outputting the integrated block frequency corresponding to the threshold of the integrated frequency distribution table.

In addition, the 3rd hierarchical frequency distribution table of FIG. 29 shows the case of 2 variables, and expands the formula (14), and the integrated frequency distribution table is produced | generated

Get Where SUM (·) represents the integrated block frequency, N (·) represents the block frequency in the frequency distribution table, act3 represents the third hierarchical corresponding variable in the integrated frequency distribution table, and act4 represents the zero in the integrated frequency distribution table. ACT3 represents the third hierarchical variable in the frequency distribution table, ACT4 represents the fourth hierarchical variable in the frequency distribution table, and n represents the variable maximum in the frequency distribution table.

In the integrated frequency distribution table generated according to the equation (15), the sum of the block counts corresponding to the addresses of the determination threshold TH3 of the third layer and the determination threshold TH4 of the fourth layer is equal to or greater than the threshold TH3 or the determination threshold TH4. Display. As a result, the amount of information generated in the third layer can be calculated.

Regarding the frequency distribution tables of the second and first hierarchies of FIG. 30, the integrated frequency distribution table can be used to shorten the block frequency calculation time.

In this case, the number of integrations increases as the number of block activity variables increases.

First, the expression in the case of the second layer is given by

Indicated by. Where SUM (·) denotes the integrated block frequency, N (·) denotes the block frequency in the frequency distribution table, act2 denotes the second hierarchical corresponding variable in the integrated frequency distribution table, and act3 denotes the integrated frequency distribution table. Represents the third hierarchical correspondence variable in, act4 represents the fourth hierarchical correspondence variable in the integrated frequency distribution table, ACT2 represents the second hierarchical variable in the frequency distribution table, and ACT3 represents the third hierarchical variable in the frequency distribution table. ACT4 indicates the fourth hierarchical variable in the frequency distribution table.

In the integrated frequency distribution table generated according to (16), the integrated block frequency corresponding to the address of the determination threshold TH2 of the second layer, the determination threshold TH3 of the third layer, and the determination threshold TH4 of the fourth layer is equal to or greater than the threshold TH2. And the sum of the counts of the threshold TH3 or more and the judgment threshold TH4 or more.

Accordingly, the amount of information generated in the second layer can be calculated.

Finally, the process regarding the frequency distribution table of the 1st layer shown to FIG. 30B (B) is demonstrated.

In this case, there are 4 types of block activity variables, so that the number of times of accumulation is the highest. Here, the formula in the case of the first layer is

Indicated by. Where SUM (·) represents the integrated block frequency, N (·) represents the block frequency in the frequency distribution table, act1 represents the first hierarchical corresponding variable in the integrated frequency distribution table, and act2 represents the integrated frequency distribution table. The second hierarchical correspondence variable, act3 represents the third hierarchical correspondence variable in the integrated frequency distribution table, act4 represents the fourth hierarchical correspondence variable in the integrated frequency distribution table, and ACT1 represents the first hierarchical variable in the frequency distribution table. Represents a variable, ACT2 represents a second hierarchical variable in the frequency distribution table, ACT3 represents a third hierarchical variable in the frequency distribution table, and ACT4 represents a fourth hierarchical variable in the frequency distribution table.

In the integrated frequency distribution table generated by equation (17), an integration block corresponding to the address of the determination threshold TH1 of the first layer, the determination threshold TH2 of the second layer, the determination threshold TH3 of the third layer, and the determination threshold TH4 of the fourth layer. The frequency represents the sum of the blocks of the threshold TH1 or more, the threshold TH2 or more, the threshold TH3 or more and the threshold TH4 or more. Accordingly, the amount of information generated in the first layer is also calculated.

As a result of the processing, calculation of the amount of generated information based on the number of blocks to be divided in each layer by the expression (12) is realized.

By introducing the above-described integrated frequency distribution table, it is possible to significantly shorten the generation information amount control time. A method of further reducing the amount of information information control time generated for this integrated frequency distribution table is shown.

The integrated frequency distribution table used in this proposal is used to calculate the amount of occurrence information for the division decision threshold. In actual threshold processing, a large determination threshold cannot be used practically from the viewpoint of image quality deterioration. Therefore, it is proposed to prepare a frequency distribution table in which the block activity values are gripping. The aspect is shown in FIG. 33 and FIG.

As shown in FIG. 33, when the block activity value is clipped to LMT, all block counts of LMT or more are registered in the LMT in the frequency distribution table. As a result, the block frequency in the LMT increases as shown in the figure. The calculated block count is in the diagonal line.

33 shows an integrated frequency distribution table for this frequency distribution table. The integration operation shown in equations (14) to (17) is performed not in the maximum value n of the block activity value but in a section from the block activity value LMT to zero.

The block frequency sum to calculate is the integrated block frequency I of the coordinate of threshold TH. As in this example, the same result as in the thirty-second degree is obtained. By introducing clipping into the block activity value of the frequency distribution table, it is possible to shorten the integrated frequency distribution table creation time and reduce the frequency distribution table memory space.

As the configuration to apply this method, two kinds of cases are considered: a case where the clipped value LMT is changed for each layer and a case where the clipped value LMT is fixed to the entire layer.

The former is used when there is a distinct difference in the distribution of differences between the hierarchies of each layer, and the latter is used when there is no significant difference between the hierarchical differences in each layer.

35 shows a flowchart of the hierarchical encoding process. In step SP2, "4" is registered in the hierarchical counter 1 which stores the hierarchical number, and the hierarchical frame is determined.

Further, in step SP3, hierarchical data is generated by the generation information amount calculation, and each block activity is detected in step SP4. By generating and registering the multidimensional frequency distribution table described above with reference to FIG. 29 in step SP5 for this activity, the amount of generated information is controlled and the optimum control value is determined.

In step SP6, hierarchical encoding is executed on the encoder side based on the control value. That is, encoding and complexing are initially performed on 5-layered data, which is the highest layer. The result is the initial value of the process in the lower layer, and the difference value between layers with the lower layer is generated in step SP7. In step SP8, segmentation selection and encoding in the lower layer are executed based on the occurrence information amount control value determined in the upper stage.

After each layer process, the layer counter I is decremented in step SP9. In step SP10, the termination judgment is performed on the contents of the hierarchy counter I. FIG. If not, the lower layer process is executed again. When the processing of all the layers is finished, the processing exits from the loop and the processing ends in step SP11.

According to the amount of abnormality occurrence information, hierarchical coding with high pressure efficiency with small image quality deterioration can be performed.

(4) Another embodiment of the fourth embodiment

(4-1) In the above embodiment, the case where the block activity P is determined as the maximum value of the difference between the decoded data obtained for the upper layer data and the lower layer data for each block will be described. Instead, the average error, the absolute value, the standard deviation, the n sum, and the data frequency of the threshold value or more may be determined within the block.

(4-2) In the above embodiment, the case where the image data is PCM coded in the encoder has been described. However, the present invention is not limited thereto, and other coding methods such as orthogonal coding methods may be applied.

(4-3) In the above embodiment, a case is described in which a plurality of combinations are stored in a ROM for the threshold values of the frequency distribution table obtained for each layer, and a combination of threshold values for which the amount of generated information is closest to the target value is described. The invention is not limited to this and may be set independently for each layer.

(4-4) In the above embodiment, a description will be given of obtaining the upper layer image data by averaging the lowest layer data by 2 lines x 2 pixels, but the present invention is not limited thereto, and the average value may be obtained by other combinations. .

(5) As described above, according to the present invention, when image data is sequentially recursively divided into a plurality of hierarchical data having a plurality of different resolutions, the block activity is determined for a predetermined block of the hierarchical data, and the lower hierarchical data is determined. By setting the threshold value, which is a criterion for the division processing for the above, in the frequency distribution of the block corresponding to the block activity, the hierarchical coding method of the best data with which the compression efficiency does not decrease can be easily realized.

[6] fifth embodiment

(1) The picture coding apparatus of the fifth embodiment

The image encoding device 90 of the fifth embodiment has a schematic structure similar to that of the third embodiment (Figure 11), as shown in FIG. 36, and hierarchically encoded encoder portion hierarchically encoding and outputting input image data D31. It consists of the generation information amount control part 90B which controls 90 A and the hierarchical encoding encoder part 90A so that the generation information amount may achieve a target value.

The hierarchical encoding encoder section 90A includes a memory for data delay (not shown) and an encoder. Among them, a memory is provided at the input terminal to delay the data so that encoder processing is not executed until the optimum control value is determined by the generation information amount control unit 90B.

On the other hand, the generation information amount control unit 90B inputs the input image data to determine a threshold TH suitable for the processing target data, and transmits the optimum control value determined in the hierarchical encoding encoder unit 90A to encode the input image data D31 efficiently, to the encoder. This is a configuration of so-called feed forward type buffering. This configuration makes it possible to eliminate the time delay caused by accurate amount of information control and feed forward buttering.

Here, the division process in the lower layer is selected by the block activity defined based on the inter-layer difference value. That is, higher layer data is constructed and blocks are defined than 4 pixels of 2 x 2 of the lower layer.

In other words, if the upper layer data is referred to as XO (i + 1) and the lower layer data is referred to as Xj (i), the inter-layer difference coded value? Xj (i) = XO (i + 1) -Xj (i). However, j = 0-3. If the block activity determination function is G (·), then the block activity ACT = G (ΔXj (i)).

The method of confirming the division determination flag will be described with the division stop as the case where the hierarchical determination flag FLG is 0 and the division continued as the case where the hierarchical determination flag FLG is 1. First, in the generation information amount control process, an activity ACT of all layers is initially generated for each block, and then a determination flag FLG is generated according to a threshold corresponding to the activity ACT of all layers. In each block, the first layer is searched for from the lower layer to the first flag FLG.

The hierarchical decision flag FLG of the entire upper hierarchical block higher than the hierarchical layer where the decision flag FLG becomes 1 is set to 1. In accordance with this rule, the determination flag FLG is updated. In addition, the determination threshold is changed based on the control of the amount of information generated, and an optimum threshold that satisfies the target value is selected. In this regard, in the case of the embodiment, the decision flag used herein is separate from the decision flag used in the encoding process.

Next, the block division selection process (that is, the actual encoding process) will be described. If the determination flag FLG = 0, the division of the lower layer is stopped, and if the determination FLG = 1, the division of the lower layer is executed. The above process consists of two steps of determining the layer determination flag FLG for each block of each layer by preliminary generation information amount control and executing the actual block dividing process based thereon.

(2) hierarchical encoding encoder

The hierarchical encoding encoder section 90A is the configuration shown in FIG. 37 and has the same configuration as in FIGS. 12 and 13 except that the encoders 51 to 55 are configured as in FIG.

In this case, the encoders 54, 53, and 52 transmit the threshold determination result information 1, J2, and J3, which are used to indicate division or non-division of the blocks, to the encoders 53, 52, and 51 of the adjacent lower layer, respectively. 51, 52, and 53 transmit the threshold determination result information J4, J3, J2 to the encoders 52, 53, 54 of the adjacent upper layer, respectively.

In other words, the hierarchical encoding encoder 90A returns to the hierarchical layer where the dividing process is interrupted when the attention activity is detected in the subsequent lower hierarchies even for a block in which the dividing process is interrupted due to the threshold determination of the hierarchical data. The threshold flag is reset, and the threshold value determination is made again toward the lower layer.

This is because, in the hierarchical data structure, the number of lower hierarchical data corresponding to the higher hierarchical block is increasing, so that the justice of the judgment is recognized.

In practice, the encoders 52 and 53 are configured as shown in FIG.

The encoder 53 inputs the difference data D43 to the activity detection circuit 53C of the encoding circuit 53A and the division controller 53B. The activity detection circuit 53C detects the activity for each predetermined block of the difference data D43 and continuously provides the detection result obtained to the threshold determination circuit 53D. The threshold determination circuit 53D compares the activity detection result for each block with the threshold data D57, and sends the determination result obtained therefrom to the encoding circuit 53A and the encoder 52 of the adjacent lower layer as the threshold determination result information J2. On the basis of the threshold determination result information J2, the encoding circuit 53A compresses and transmits the block with the high activity and does not transmit the block with the low activity.

In this case, the activity detection circuit 53C and the threshold determination circuit 53D receive the threshold determination result information J1 outputted from the encoder 54 of the adjacent higher layer and indicate that the threshold determination result information J1 performs block division. The detection and threshold determination results are executed. On the other hand, when the threshold determination result information J1 indicates the non-division of the block, the activity corresponding to the block corresponding thereto is not detected, and the threshold determination result indicating the non-division of the block from the threshold determination circuit 53D is performed. Output the information J2.

Similarly, the encoder 52 performs the activity detection and threshold determination on the corresponding block when the activity detection circuit 52C and the threshold determination circuit 52D receive the threshold determination result information J2 indicating the division of the block from the encoder 53 of the adjacent upper layer. On the other hand, when receiving the threshold determination result information J2 indicating the non-division of the block, the activity detection and threshold determination are not executed, and the threshold determination result information J3 indicating the non-division of the block is output from the threshold determination circuit 52D. do.

In this way, in the hierarchical encoding encoder unit 90A, once the non-division determination result of the block is obtained, the block corresponding thereto is not divided (i.e., not encoded) into the lower layer after that.

In addition, in the hierarchical encoding encoder 90A, for example, even when the threshold determination result information J2 indicating the non-division of the block is obtained by the division controller 53B of the encoder 53, for example, the threshold determination result information J4 indicating the division of the block by the encoder 51 is obtained. If is obtained, the encoder 52 receives the threshold determination result information J4 from the division control unit 52B, performs a threshold determination of the block activity, and determines whether to divide the block.

(3) occurrence information amount control unit

Next, FIG. 39 shows an example of the configuration block diagram of the generation information amount control unit.

First, a quarter averaging process is performed in the averaging circuit 42 on the input image data D31 as in the encoder section of FIG. 39 to generate the second hierarchical data D32.

Further, a quarter averaging processing is performed in the averaging circuit 44 with respect to the second hierarchical data D32 to generate the third hierarchical data D33.

Similarly, the fourth hierarchical data D34 is generated by the quarter averaging processing of the averaging circuit 46 with respect to the third hierarchical data D33.

Finally, the fifth hierarchical data D35 by quarter averaging in the averaging circuit 48 is generated.

In the fifth hierarchical data D35, the frequency of data is registered in the frequency distribution table 73. This measures the data count corresponding to the compression process performed in the encoder section. For example, when the compression processing under the PCM code is performed on the fifth layer data D35, the dynamic range given for each block is registered as data, and ADRC (Adaptive Dynamic Range Coding (USP-4703352)) is applied as the compression processing method. In this case, the DR of the ADRC block is registered.

Next, difference data D64 is generated from the fourth layer data D34 and the fifth layer data D35. The block activity detection described above with respect to the difference data D64 is performed in the block activity detection circuit 68. The block activity D68 detected here is registered in the frequency distribution table 72.

The block division decision at the upper layer is determined by referring to the determination result of the entire lower layer block activity.

The frequency distribution table 72 is defined by four variables of the first layer block activity D65, the second layer block activity D66, the third layer block activity D67, and the fourth layer block activity D68.

The difference data D63 is generated from the third layer data D33 and the fourth layer data D34. The block activity is detected in the activity detection circuit 67 with respect to the difference data D63. The detected activity D67 is registered in the frequency distribution table 71.

Also in this case, the block division is determined by referring to the determination result of the block activities of the entire lower layer below the third layer.

Therefore, the frequency distribution table 71 of the third layer is defined by three variables of the first layer block activity D65 and the second layer block activity D66 and the third layer block activity D67.

The difference data D62 is generated from the second layer data D32 and the third layer data D33, and the block activity D66 is outputted to the activity detection circuit 66. The detected block activity D66 is registered in the frequency distribution table 70.

In this case, it is determined by referring to the determination result of the block activity of the first layer.

The frequency distribution table 70 of the second layer is defined by two variables of the first layer block activity D65 and the second layer block activity D66.

Finally, the difference data D61 is generated from the first layer data D31 and the second layer data D32, and the block activity D65 is output by the activity detection circuit 65. The detected block activity D65 is registered in the frequency distribution table 69.

As for the first layer, the result is executed without performing the threshold value determination of the block activity independently, and there is no need to monitor the block activity of the upper layer. That is, the frequency distribution table 1 of a 1st hierarchy becomes a 1-dimensional frequency distribution table comprised from the 1st hierarchy block activity D65.

In order to accurately determine the amount of data transmitted by the encoder, three pixels that are actually transmitted by the encoder are used among the lower layer 4 pixels corresponding to the upper layer 1 pixel.

The amount of occurrence information is controlled by using the frequency distribution tables 69 to 73 thus generated. Each frequency distribution table and the control part of the rear end are connected to D69-D73 by bidirectional signals.

The control unit first transmits a threshold for each frequency distribution table to each frequency distribution table.

In each frequency distribution table, the generation information amount corresponding to a threshold value is detected.

The amount of information generated in each frequency distribution table is transmitted to the control unit 74 via the signals D69 to D73.

The control unit 74 calculates the total amount of occurrence information to be controlled by integrating the amount of occurrence information in each received frequency distribution table.

The total value of the generated information is compared with the target value, and the threshold value is changed to satisfy the target value by the comparison result.

The updated threshold value is transmitted from the controller 74 to each frequency distribution table via signals D69 to D73.

The amount of generated information corresponding to this is transmitted back to the controller.

By repeating the above process, the control result D57 which finally achieves the target value is determined.

The determined generation information amount control value D57 is transmitted to the hierarchical encoding encoder as in the block diagram of FIG.

During this information amount control unit processing period, data to be controlled is waited by the memory M1 included in the encoder unit.

In the above information amount control, a threshold value suitable for the target data is determined, so that efficient encoding can be realized.

40 (A) to 40 (E) show frequency distribution tables of block activities obtained for the highest hierarchical data and the lowest hierarchical data, respectively. As to the frequency distribution table for the fifth layer shown in FIG. 40A, the frequency distribution table based on the dynamic range is generated because the target data is not the difference data. For example, when the compression process by PCM encoding is performed on the fifth layer data D35, the dynamic range given to each block is registered as data, and when ADRC (Adaptive Dynamic Range Coding (USP-4703352)) is applied as the compression processing method. The DR of the ADRC block is registered.

Next, an example of the frequency distribution table for controlling the generation information amount is shown in FIGS. 41 to 47 for the case of five hierarchies.

First, a definition formula for calculating the total amount of information generated is derived.

In order to calculate the amount of occurrence information, it is necessary to measure the number of effective blocks equal to or greater than the division determination threshold in each layer. However, in the generation information amount control of hierarchical coding by the decision flag check method, the result of division determination of all lower layers in the upper layer is taken into account in each block. To determine the division of the target block.

At this time, the block activity determination threshold used in the segmentation determination in each layer is the first layer segmentation determination threshold value TH1, the second layer segmentation determination threshold value TH2, the third layer segmentation determination threshold value TH3, and the fourth layer segmentation determination threshold value Let TH4 be used.

Lower layer division of blocks above the threshold in the entire layer is performed. In the upper layer, when there is no block activity above the threshold in the entire lower layer, block division is stopped when the block activity of the layer is less than the threshold.

41 (A) shows the frequency distribution table of the fifth layer which is the highest layer.

In the frequency distribution table of the fifth layer, since the target data is not the difference data, the information amount control corresponding to the encoding process is performed.

When fixed length coding such as linear quantization is applied, it is not necessary to create a frequency distribution table. The following generation information amount calculation formula can be used for generation information amount control.

That is, if the pixel number in the segment to be divided in the first layer is M1, the number of quantization bits of the first layer data is Q1, and the number of decision flags bits of the first layer is N1, the amount of information I1 generated in the first layer is

Can be given by

In Equation (18), the number of bits in the first term is quadrupled because each block is divided into two lines by two pixels in this example. Also, in the structure of claim 1, 3/4 times means that the higher hierarchical value is generated from the average value of the lower hierarchical values. This is because it limits the nature of the tooth to be restored.

The addition of N1 to the number of blocks in the first layer indicates the transmission of an additional 1 bit for each block as the division determination flag.

Similarly, in the second, third, and fourth layers, the sum of the pixels in the divided blocks in each layer is M2, M3, and M4, and the number of quantization bits in each layer is Q2, Q3, Q4, and the number of decision flag bits in each layer. Let N2, N3, N4, the amount of information Ik (k = 2, 3, 4) generated in each layer is

Provided by

When the generation information amount I1 to I4 for the first to fourth layers and the generation information amount I5 for the fifth layer are used, the total amount of generation information I generated by the encoding processing of the hierarchical encoding encoder 40A is expressed by the following equation.

As described above, it can be obtained as the sum of the amount of generated information for each layer.

Here, the number of bits of the determination flag is added to the amount of information generated in each layer, but the information amount of this flag is the same as the number of blocks for which division processing is performed in the upper layer. The spatial position of each block is specified in each layer by the history of the decision flag from the upper layer.

Here, each frequency distribution table is demonstrated.

As described above, the frequency distribution table of the highest layer data depends on the compression method and cannot be determined uniformly. However, the amount of information generated can be controlled by means such as a frequency distribution table.

Next, as to the first hierarchical data, the block frequency for the block activity ACT1 is registered. By using the first hierarchical frequency distribution table in FIG. 41, the amount of occurrence information for the threshold TH1 can be easily calculated.

Since blocks equal to or larger than the threshold TH1 are to be divided, the amount of generated information is calculated in the first layer by obtaining the sum of the blocks equal to or greater than the threshold.

Next, FIG. 42 shows an example of the frequency distribution table of the second hierarchy.

In the determination flag confirmation method, the number of blocks of the threshold TH2 or more in the second layer is measured for the block that has received the block division execution stop determination in the first layer.

Here, a frequency distribution table defined by two variables of the first layer block activity ACT1 and the second layer block activity ACT2 is introduced.

That is, the block count of the threshold TH2 of the 2nd layer or more is calculated | required more than the threshold TH1 of a 1st layer.

This operation calculates the amount of information generated in the second layer that satisfies the above conditions by calculating the block count of the ACT1 axis equal to or greater than the threshold TH1 and the ACT2 axis equal to the threshold TH2 in the frequency distribution table of FIG.

42 shows a case where ACT1 is measured discretely, and the block activity ACT2 of the second layer is distributed for each value of ACT1.

43 shows an example of the frequency distribution table of the third and fourth hierarchies.

Similar to the frequency distribution table of the second hierarchy, a frequency distribution table defined by multivariables is generated.

In the third layer, blocks defined by the block activities ACT1, ACT2, and ACT3 of the first layer, the second layer, and the third layer are registered in the frequency distribution table. The state is shown in FIG. 43 (A).

In the third layer, the amount of information generated in the third layer is calculated by calculating block counts of TH1 or more on the TCT1 axis, threshold 2 or more on the TCT2 axis, and threshold TH3 or more on the ACT3 axis.

In the fourth layer, blocks defined in the respective block activities ACT1, ACT2, ACT3, and ACT4 of the first, second, third, and fourth layers are registered in the frequency distribution table. The state is shown in FIG. 43 (B).

In the case of the fourth layer, the amount of information generated in the fourth layer is calculated by calculating a block count of TH1 or more on the ACT1 axis or more than TH2 or more on the ACT3 axis or TH3 or more on the ACT3 axis or TH4 or more on the ACT4 axis.

The above five types of frequency distribution tables can be used to calculate the amount of information generated about the threshold and to perform control that matches the target information amount.

Here, there is a method of changing the threshold of each layer independently used for each layer independently for each layer.

For example, a method of controlling a target information amount in advance for each layer and changing an independent threshold value for each layer to match the target information amount.

Another method is to simplify the control by preparing a combination of thresholds of each layer in advance and applying the threshold combinations according to the control order.

Next, the frequency distribution table will be described.

In the above-described method for controlling the amount of information generated using the frequency distribution table in each of the above layers, each layer detects the optimal control value by calculating block counts above the threshold while considering the result of division decision of the entire lower layer.

In order to speed up the calculation time of the block frequency above the threshold, it is proposed to reconstruct the frequency distribution table in which the block frequency is registered in the integrated frequency distribution table.

An example of the integrated frequency distribution table is shown in FIG. 45.

As a result of registering the block activity, the frequency distribution table example in FIG. 44 is obtained. To simplify the explanation, the block activity takes an example of one variable.

The integrated frequency distribution table (fig. 45) starts from the block frequency corresponding to the maximum value of the block activities in the frequency distribution table of FIG. 44, performs an integration operation on the block frequency corresponding to the smaller block activity value, and integrates each of them. The results are registered in the frequency distribution table and restructured.

The following expression expresses this process as a formula

Indicated by. Where SUM (·) denotes the integrated block frequency, N (·) denotes the block frequency in the frequency distribution table, act denotes the block activity variable in the integrated frequency distribution table, and ACT denotes the block in the frequency distribution table. Indicate activity variables, where n represents the variable maximum in the frequency distribution table.

Equation (21) means a process of reading the block count of a block activity value address and adding the result to the integrated value up to the higher block activity value to the block activity value address.

The result is shown in FIG. In the integrated frequency distribution table, the block frequency sum of the oblique portions in FIG. 44 corresponds to the threshold TH coordinate data I. FIG.

Since the threshold value TH is changed by this integrated frequency distribution table, it is not necessary to calculate the block frequency sum of the oblique portions of FIG. 44 each time.

That is, the calculation of the block frequency sum is realized by outputting the integrated block frequency corresponding to the threshold of the integrated frequency distribution table.

FIG. 45 is also present in the example of one variable and is applied to the first hierarchical frequency distribution table of FIG.

The second hierarchical frequency distribution table in FIG. 42 shows the case of the second variable, and the integrated frequency distribution table is generated by expanding the expression (21).

Is displayed. Where SUM (·) denotes the integrated block frequency, N (·) denotes the block frequency in the frequency distribution table, act1 denotes the first hierarchical corresponding variable in the integrated frequency distribution table, and act2 in the integrated frequency distribution table. Denotes the second hierarchical corresponding variable in, ACT1 denotes the first hierarchical variable in the frequency distribution table, ACT2 denotes the second hierarchical variable in the frequency distribution table, and n denotes the variable maximum in the frequency distribution table.

In the integrated frequency distribution table generated according to the equation (22), the integrated block frequency corresponding to the address of the determination threshold TH1 of the first layer and the determination threshold TH2 of the second layer is equal to or greater than the first layer threshold TH1 and the second layer determination threshold TH2. The above-described block frequency sum is shown.

Accordingly, the amount of information generated in the second layer can be calculated.

Also in the frequency distribution tables of the third and fourth hierarchies of FIG. 43, the integrated frequency distribution table can be used to shorten the calculation of the block frequency sum.

In this case, the number of block activity variables increases, which increases the number of integrations.

First, the expression in the case of the third layer is given by

Indicated by. Where SUM (·) denotes the integrated block frequency, N (·) denotes the block frequency in the frequency distribution table, act1 denotes the first hierarchical variable in the computational frequency distribution table, and act2 denotes the integrated frequency distribution table. Represents the second hierarchical correspondence variable in, act3 represents the third hierarchical correspondence variable in the integrated frequency distribution table, ACT1 represents the first hierarchical variable in the frequency distribution table, and ACT2 represents the second hierarchical variable in the frequency distribution table Where ACT3 represents the third hierarchical variable in the frequency distribution table, and n represents the variable maximum in the frequency distribution table.

In the integrated frequency distribution table generated according to (23), the integrated block frequency corresponding to the address of the determination threshold TH1 of the first layer, the determination threshold TH2 of the second layer, and the determination threshold TH3 of the third layer is the first layer threshold. The sum of blocks above TH1 and above the second layer threshold TH2 and above the third layer TH3.

Accordingly, the amount of generated information can be calculated in the third layer.

Processing relating to the frequency distribution table of the fourth hierarchy in FIG. 43 will be described in detail.

In this case, the number of block activity variables is four, which increases the number of integration operations.

The formula in the case of the fourth layer is

Indicated by. However, SUM (·) denotes the integrated block frequency, N (·) denotes the block frequency in the frequency distribution table, act1 denotes the first hierarchical corresponding variable in the integrated frequency distribution table, and act2 denotes the integrated frequency distribution table. Represents the second hierarchical correspondence variable in, act3 represents the third hierarchical correspondence variable in the integrated frequency distribution table, act4 represents the fourth hierarchical correspondence variable in the integrated frequency distribution table, and ACT1 represents the fourth hierarchical correspondence variable in the frequency distribution table. Denotes a hierarchical variable, ACT2 denotes a second hierarchical variable in the frequency distribution table, ACT3 denotes a third hierarchical variable in the frequency distribution table, ACT4 denotes a fourth hierarchical variable in the frequency distribution table, n Denotes the variable maximum in the frequency distribution table.

In the integrated frequency distribution table generated by Equation (24), an integration block corresponding to the address of the determination threshold TH1 of the first layer, the determination threshold TH2 of the second layer, the determination threshold TH3 of the third layer, and the determination threshold TH4 of the fourth layer. The frequency count represents the sum of the frequency counts of the first layer threshold TH1 or more, the second layer threshold TH2 or more, the third layer threshold TH3 or more, and the fourth layer threshold TH4 or more.

Accordingly, the amount of information generated in the fourth layer is also calculated.

As a result of the processing, calculation of the amount of generated information is realized on the basis of the number of target blocks to be divided in each layer according to equation (19).

By introducing the above-described integrated frequency distribution table, it is possible to drastically shorten the amount of information control.

A proposal is made to further reduce the amount of information information control time generated for this integrated frequency distribution table.

The integrated frequency distribution table used in this proposal is used to calculate the amount of occurrence information for the division decision threshold.

In actual threshold processing, a large determination threshold cannot be used practically in view of deterioration of image quality. Therefore, it is proposed to create a frequency distribution table that clips the block activity values. The aspect is shown in FIG. 46 and FIG.

As shown in Fig. 46, when the block activity value is clipped to LMT, block counts of LMT or more are registered as all LMTs in the frequency distribution table.

As a result, the block frequency in the LMT becomes large. The sum of blocks to be calculated is an oblique portion.

47 shows an integrated frequency distribution table with respect to the frequency distribution table. The integration operation represented by the formulas (21) to (24) is performed not in the maximum value n of the block activity value but in a section from the block activity value LMT to zero.

The block frequency sum to be calculated is the integrated block frequency I of the coordinates of the threshold TH. As shown in this example, the same result as in the 45th degree is obtained. By introducing clipping into the block activity value of the frequency distribution table, it is possible to shorten the integration frequency distribution table creation time and reduce the frequency distribution table memory space.

As the configuration to which this technique is applied, two types are considered: a case where the clipped value LMT is changed for each layer and a case where the clipped value LMT is fixed for each layer.

The former is used when there is an apparent difference in the distribution of the differences between the layers of each layer, and the latter is used when there is no significant difference between the layers of each layer.

48 shows a flowchart of the hierarchical coding process, and in step SP2, "4" is registered in the hierarchical counter I which stores the hierarchical number, and the form of this hierarchization is determined.

In step SP3, hierarchical data is generated by the generation information amount calculation, and in step SP4, each block activity is detected. By generating and registering the multi-dimensional frequency distribution table described above with reference to FIG. 42 in step SP5 for this activity, the amount of generated information is controlled and the optimum control value is determined.

In step SP6, hierarchical encoding is executed on the encoder side based on the control value. That is, encoding and complexing are initially performed on 5-layered data, which is the highest layer. The result is the initial value of the process in the lower layer, and the difference value between layers with the lower layer is generated in step SP7. Next, in step SP8, division selection and encoding in the lower layer are executed based on the occurrence information amount control value determined at the upper end.

After each layer process, the layer counter I is subtracted in step SP9. In step SP10, the termination judgment is performed on the contents of the hierarchy counter I. FIG. In the case of no termination, the lower layer processing is continued again. When the processing of all the layers is finished, the processing exits from the loop and the processing ends in step SP11.

The above-described control of the amount of generated information makes it possible to perform hierarchical coding with low image quality deterioration and high compression efficiency.

(4) another embodiment

(4-1) In the above embodiment, the case in which the block activity P is determined as the maximum value of the difference between the decoded data obtained for the upper hierarchical layer and the lower hierarchical data for each block has been described. It is not limited to this, but may be judged by the mean error, the absolute value, the standard deviation, the n sum, and the radar frequency of the threshold value or more.

(4-2) In the above embodiment, the case where the image data is PCM coded by the encoder has been described. However, the present invention is not limited to this, and other coding methods such as orthogonal coding methods may be applied.

(4-3) In the above embodiment, a case has been described in which a plurality of combinations are stored in the ROM for the threshold values of the frequency distribution table obtained for each layer, and a combination of the threshold values where the amount of generated information is closest to the target value has been described. It is not limited to this, but may be set independently for each layer.

(4-4) In the above embodiment, a case has been described in which the lowest hierarchical data is obtained by averaging 2 lines x 2 pixels to obtain the highest hierarchical data of the upper hierarchical data. You may calculate an average value.

(5) As described above, according to the present invention, when image data is sequentially recursively divided into a plurality of hierarchical data having different resolutions, the block activity is determined for a predetermined block of the hierarchical data, and the lower hierarchical data is determined. The hierarchical coding method of image data without deterioration in compression efficiency can be easily realized by setting a threshold value as a criterion for the division processing for the data from a frequency distribution table of blocks corresponding to the block activity.

[7] sixth embodiment

(1) The picture coding apparatus of the sixth embodiment

The picture coding apparatus 100 of the sixth embodiment has a schematic structure similar to that of the third embodiment (figure 11) as shown in FIG. 49, and the hierarchical encoding encoder section 100A for hierarchically encoding the input image data D31 and outputting the same. It is comprised by the generation information amount control part 100B which controls so that the generation information amount in the hierarchical encoding encoder part 100A may become a target value.

The hierarchical encoding encoder section 100A is composed of a memory M1 (figure 50) for data delay and an encoder. The memory M1 is provided at the input such that the data is delayed so that encoder processing is not executed until the optimum control value is determined in the generation information amount control unit 100B.

On the other hand, the generation information amount control unit 100B inputs the input image data D31 to set the optimum control value S1 suitable for the processing target data, and sends this to the hierarchical encoding encoder 40A so that the hierarchical encoding encoder 40A can perform efficient encoding. This is a so-called feed forward type buffering configuration.

(2) hierarchical encoding encoder

The hierarchical encoding encoder section 100A generates compressed image data having different resolutions in five hierarchies as shown in FIG. 50, and the points and encoders 51 to 55 where the input image data D31 is to be inputted through the memory M1 are different from those in FIG. Except for the configuration described above, FIGS. 12 and 13 have the same configuration as above.

In such a case, the encoders 51 to 55 execute block division determination using the relationship between signals existing in the same space. That is, in FIG. 51, the encoder 54 inputs the difference data D44 to the encoding circuit 54A, and to the color signal detection circuit 54B and the luminance signal detection circuit 54E. The frequency signal detection circuit 54E extracts the luminance component included in the difference data D44, and then detects the activity for each block of the extracted luminance component by the activity detection circuit 54F. Threshold determination circuit 54G compares the detected luminance signal activity with a predetermined threshold, and continuously provides the threshold determination result obtained to threshold setting circuit 54H. In the threshold setting circuit 54H, when the determination result in the threshold determination circuit 54G indicates that the luminance signal activity is larger than the predetermined threshold, a relatively small threshold is set, and the threshold value of the luminance signal activity is higher than the predetermined threshold. If the page indicates a small one, a relatively large threshold is set. At this time, the threshold setting circuit 54H determines the magnitude of the threshold to be set according to the optimum control value S1. The threshold thus set is provided to the threshold determination circuit 54D.

In the encoder 54, the activity for each block of the color signal components extracted by the color signal detection circuit 54B is detected by the activity detection circuit 54C, and the color signal activity obtained thereby is provided to the threshold determination circuit 54D.

The threshold determination circuit 54D thresholds the color signal activity by the threshold set in the threshold setting circuit 54H, and controls the block division in the coding circuit 54A in accordance with the determination result. In other words, block division is not performed when the color signal activity is higher than or equal to the set threshold, whereas block division is not performed when the color signal activity is lower than the threshold.

As described above, in the encoder 54 (the same is true for the encoders 51 to 53), the threshold is set once based on the activity of the luminance signal, the activity of the color signal is determined using the set threshold, and the block is divided according to the determination result. To control.

Here, activity refers to the maximum value, average value, absolute value, standard deviation, or n sum of interlayer difference data D41 to D44 in a predetermined block when the lower layer data area corresponding to the upper layer is defined as a "block". Correlation value displayed. In other words, when the activity is low, the block is a flat block.

If the block activities are higher than a predetermined threshold, the encoders 51 to 54 encode the data as the block as the partitioned block and transmit the data of the block, and attach and send a partition decision flag indicating that the block is the partitioned block. do.

On the other hand, the encoders 51 to 54 determine that the block is a non-divided block when the block activity is less than a predetermined threshold, and that the data of the block is not transmitted and that the block is a non-divided block. Add a block and send it. This undivided block is replaced with higher layer data on the decoding device side.

(3) division processing

In the hierarchical codes and methods in this embodiment, a method is used in which the determination flag is not reflected in subsequent determinations in the lower hierarchies (hereinafter referred to as an independent judging method). The division selection process is performed based on the determination. For example, even in a block once determined to be non-divided, the activity is again determined in the subsequent lower hierarchies, and it is selected whether to re-divid or not to divide. As a result, in the hierarchical coding method using the independent judging method, hierarchical coding with less image quality deterioration is realized by not being influenced by the decision flag of the lower layer in the upper layer.

In addition to the above configuration, the hierarchical encoding encoder 100A does not perform division determination of the color signal independently, but performs division determination of the color signal while considering luminance signals in the same space mutually correlated with the color signals.

In the hierarchical encoding encoder 100A, the threshold value used for the block division determination of the color signal is changed in accordance with the block activity of the luminance signal.

That is, in the hierarchical encoding encoder 100A, the data value of the color signal upper layer data X _{i + 1} (0), the data value of the color signal lower layer data X _i (j) = [j = 0 to 3], and the difference code value between the color signal layers. ΔXi (j) = X _{i + 1} (0)-X _i (j) [j = 0-3], the color signal block activity determination function is G (·), the color signal block activity ACTc = G (ΔXi ( j)) [j = 0 to 3], when the luminance signal block activity in the same space is ACR _Y , when the luminance signal block activity ACT _Y is equal to or greater than the predetermined threshold TH0, the division determination threshold TH of the color signal is set to TH0c. When the luminance signal block activity ACT _Y is less than the threshold TH0, the division determination threshold TH of the color signal is set to THIc (> TH0c).

In the hierarchical encoding encoder 100A, when the color signal block activity ACTc is greater than or equal to the threshold TH, the division in the lower layer is stopped when the color signal block activity ACTc is less than the threshold TH. .

Here, for example, when the luminance signal block activity ACT _Y is equal to or larger than the threshold TH0, this indicates a case where the change in the luminance signal is large, such as an object outline, and in this case, the hierarchical encoding encoder 100A is a division decision threshold TH of the color signal, which is relatively small. The division determination threshold TH0c is adopted to control the division in the same direction as the luminance signal.

In contrast, when the luminance signal block activity ACT _Y is less than the threshold TH0, this indicates that the change in the luminance signal is not large. In this case, the hierarchical encoding encoder 100A is the division determination threshold TH of the color signal, which is higher than the division determination threshold TH0c. The compression efficiency is improved by employing a large division determination threshold THIc.

Here, as in the embodiment, when the threshold TH is changed according to the luminance signal block activity ACT _Y to control the division of the color signal, and when the block activity is determined below the predetermined threshold to control the division of the color signal. A comparison of the waveforms is shown in FIG.

FIG. 53 shows a waveform of a one-dimensional signal for explanation, and assumes a color image as an encoding target. As an example, as shown in Figs. 53A and 53B, a signal in which the luminance signal changes abruptly and the color signal change is relatively small with respect to the change in the luminance signal like the edge of the object are encoded.

In this way, for the color image signal, the division result of the color signal in the case of controlling the division by determining the block activity under a certain threshold is as shown in Fig. 53C. FIG. 53C shows that the non-division processing is selected for all blocks in which the color signal is displayed.

Obviously from Fig. 53 (C), when the block activity is determined under the predetermined threshold and the division of the color signal is controlled, the color signal is changed at the edge of the object due to the difference between the luminance signal and the division result of the division of the color signal. If the change is relatively small, the non-dividing process is selected. As a result, the signal waveform becomes stepped by using higher layer data as the restored value of the undivided block data. In general, the stepped waveform is inconspicuous, but the stepped waveform is recognized as a deterioration in image quality of the color signal in the flat portion near the place where the luminance signal changes sharply.

In particular, the difference in image quality is prominent due to the difference in processing between the luminance signal and the color signal that exist in the same space, such as when the luminance signal and the color signal have different block sizes. In this way, image quality deterioration based on color signals occurs.

On the other hand, in the case where the division to change the threshold value TH in accordance with the luminance signal block activity ACT _Y is controlled, as in the object contour in the center of the figure as shown in FIG. Color signal division is performed.

Therefore, the result of the division determination of the luminance signal and the color signal coincides with each other, and deterioration in image quality due to the stepped waveform of the color signal in the object contour portion can be avoided.

That is, when hierarchical coding is applied to an image composed of a plurality of signals such as a color image, the division determination for each block is not performed independently of each signal, but the division is made in consideration of the relationship between signals existing in the same space. By making the determination, the image quality can be improved.

Therefore, in the hierarchical encoding device 100, the compression efficiency is improved and the image quality deterioration is reduced.

54 shows a flowchart of the hierarchical encoding processing by the hierarchical encoding apparatus 100. In step SP2, "4" is registered in the hierarchical counter I which stores the hierarchical number, and the form of the hierarchical encoding is determined.

In the next step SP3, the generation information amount control unit 100B calculates the generation information amount to generate hierarchical data, and then each block activity is detected in step SP4. The generation information amount control unit 100B determines the optimum control value S1 in step SP5 based on the activity.

In the next step SP6, the hierarchical encoding based on the optimum control value S1 is executed by the hierarchical encoding encoder 100A. That is, encoding and complexing are initially performed on 5-layered data, which is the highest layer. The result is a process initial value in the lower layer, and the difference between layers with the lower layer is generated in step SP7. In step SP8, segmentation selection and encoding in the lower layer are executed based on the optimum control value S1 determined in step SP5.

After each layer process, the layer counter I is subtracted in step SP9. In step SP10, an end determination is made on the contents of the hierarchy counter I. FIG. If not, continue with lower layer processing again. When the process of the entire layer is finished, the process exits the loop and the layer encoding process ends in step SP11.

(4) Effect of Example

According to the above arrangement, when the block division is performed from the upper layer to the lower layer, the partition determination is made in consideration of the relationship between the signals existing in the same space, thereby realizing an image encoding method which has good compression efficiency and can reduce image quality deterioration. do.

(5) another embodiment

(5-1) In the above embodiment, the case where the division threshold of the color signal is changed based on the block activity of the luminance signal by using the luminance signal and the color signal as mutually correlated signals forming the image, The present invention is not limited to this, and may use, for example, three primary color signals of RGB as signals for forming mutually correlated color images, and may change the division threshold of a separate signal based on one signal characteristic thereof. The division threshold may be selected based on the relationship between the signals having mutual relations with each other.

(5-2) In the above embodiment, the case where the image coding method according to the present invention is applied to the independent determination method for performing the division process by determining the threshold value each time independently of each layer is described. When a decision is made to indicate that the block activity is smaller than a predetermined threshold, when the division decision is applied to the determination method of stopping the division of the subsequent lower layers once the division of the lower layers is stopped. A determination result indicating that a partition abort flag for stopping the division of the plurality of lower blocks corresponding to the block is temporarily generated and that the block activity of at least one block of the plurality of lower blocks is equal to or greater than a predetermined threshold; Applied to the decision method to change the split stop flag to a split continue flag when is obtained. Where no suitable achieve the same effect as the above embodiment.

The present invention is not limited to this, but can be widely applied to a case where a plurality of blocks having different resolutions exist in hierarchical data in the hierarchical coding scheme.

(6) As described above, according to the present invention, image data is sequentially recursively divided into a plurality of hierarchical data having a plurality of different resolutions, and except for hierarchical data except for the highest hierarchical data having the lowest resolution. The block activity is determined for a predetermined flag of the hierarchical data, and when the block activity is less than a predetermined threshold, the block division of the lower layer data corresponding to the activity-determined block is stopped, and the division stop flag is transmitted as a determination flag. In the picture coding method described above, the threshold value is selected based on a first signal among a plurality of signals forming images having mutual relations with each other, and the block activity of the second signal among the signals having a correlation with the threshold value is selected. Is compared to determine the activity of the second signal, and the block is divided based on the determination result. By controlling the image quality, compression efficiency is improved and image quality deterioration is reduced when hierarchically encoding image data.

[8] Seventh Embodiment

(1) The picture coding apparatus of the seventh embodiment

The picture coding apparatus 110A of the seventh embodiment transmits the hierarchical coded data D51 to D55 obtained from the hierarchical encoding encoder 110A in addition to the configuration of the fourth embodiment described above with respect to FIGS. 11 to 18. The block forming unit 111 reconstructs the transmission block and sends it as transmission data Dout.

(2) Data structure of transport block

Here, the data generated by the hierarchical encoding encoder 110A by the generation information amount control method as described above is output from fixed length data such as the highest hierarchical coded data D55 and the like output from the encoder 55 (FIG. 55) and from the encoders 51 to 54. It is classified into variable length data of the first to fourth hierarchical differential value encoded data D51 to D54.

For this reason, in the hierarchical encoding encoder 110A, as shown in FIG. 56, each fixed length data is collectively formed for each frame constituting the image, and the fixed length data block 120 is formed. The variable length data block 121 is collectively formed, and the variable length data block 121 is arranged after the fixed length data block 120 to form a unit block 122 (hereinafter referred to as a transfer block 122) for transmission to sequentially transfer paths. send.

In fact, in the transmission block 122, the head of the fixed-length data block 120 (that is, the head of the transmission block 122) is a SYNC code for recognizing the head position of the block 122, or an information code indicating the content of the image data (hereinafter referred to as identification information). Transport block identification code C1) is arranged. In the transport block 122, the highest layer coded data D55 is arranged immediately after the transport block identification code C1. Thus, when the desired image is searched using the identification code, the highest level coded data D55 having a small amount of information is used. The image can be sequentially restored at high speed. As a result, a high speed data search (list) function at the time of reproduction can be realized.

Further, in the hierarchical coding scheme as described above, a discrimination code for forming an image on the decoding side of the division determination flag output from the encoders 51 to 55 of the hierarchical encoder section 110A, respectively (hereinafter, collectively referred to as interlayer data). The data length of each of the division decision codes is fixed length data, which is equal to the total number of blocks in each layer.

For this reason, in the transmission block 122, as also apparent from the fifty-sixth, the inter-layer data division determination code C2 serving as the discrimination code for forming the image for each layer at these decoding sides is arranged immediately after the highest layer coded data D55. Therefore, even after the above-described generation information control is performed, the data existing in the sum of the highest hierarchical coding data D55 and the inter-layer data division determination code C2 can be fixed length as a whole.

In the variable length data block 121, the fourth to the first hierarchical differential encoded data D54, D53, D52, and D51 are formed in sequence, and immediately after the variable length data 121, a transport block for recognizing the end of the transmission block 122. Exit code C3 is added.

In the above configuration, the image encoding apparatus forms the transmission block 122 by arranging the data generated by the hierarchical encoding encoder 110A after each fixed length data after each fixed length data for each frame, and sends it to the transmission path. .

Therefore, even if an error occurs in any variable length data, the decoding side can decode the definition of the data in the fixed length data block 120 without error. As a result, in this picture coding apparatus, the transmission data has a robust characteristic against errors.

In the picture coding apparatus 110, when transmitting the data generated by the generation information amount control method, the high-speed data search function is added to the decoding side by arranging and outputting the highest hierarchical coded data D55 immediately after the transport block identification code C1. In one case, after detecting the transport block identification code C1, up to the highest layer coded data D55 can be accessed in a short time.

According to the above configuration, hierarchical coding having a plurality of resolutions can be easily realized. In addition, the total amount of generated information of the transmission image data encoded and output by the hierarchical encoding encoder 110A can almost match the target value, and encoding can be realized without a decrease in compression efficiency. In addition, hierarchical coding with less image quality degradation can be realized. In addition, management of the amount of information generated in hierarchical coding can be made easier than in the past.

In addition, by setting the optimum threshold value in consideration of the nature of the image signal data of each layer and human visual characteristics, the subjective picture quality on the receiving side can be further improved as compared with the case where the threshold value is uniformly set.

(3) Another embodiment of the seventh embodiment

(3-1) In the above embodiment, the case where the block activity is determined as the maximum value of the difference between the decoded data obtained for the upper layer data and the lower layer data for each block is explained. It is not limited to this, but may be judged based on the mean error, the absolute value, the standard deviation, the n sum, and the data frequency above the threshold.

(3-2) In the above embodiment, the case where the frequency distribution table obtained for each layer is used as it is is explained. However, the present invention is not limited to this, and the frequency distribution table of the integrated type is prepared from the frequency distribution table and used to calculate the generated information amount. You may use it.

That is, after generating the frequency distribution table for each layer, the block activity calculates the cumulative addition value for the block counts from the upper value to each block activity, and writes each cumulative addition value into an address corresponding to each block activity value. A frequency distribution of may be prepared. In this way, the frequency corresponding to each block activity is the integrated value of the block frequency having a value equal to or greater than the block activity.

Accordingly, when the preliminary integrated frequency distribution table is generated, it is unnecessary to calculate the block frequency integrated value corresponding to each threshold value, and it is possible to calculate the block frequency integrated value simply by reading the threshold address of the memory, and the time required for the calculation. We can cut drastically.

(3-3) In the above embodiment, a case has been described in which a threshold value for setting a different value for each layer is compared with a block activity, and the division / undivision of the block is determined. However, the present invention is not limited to this, but is different for each layer. The difference value between the threshold value set as the value and the data between the layers may be compared, and the division / non-division of the block may be determined based on the comparison result.

(3-4) In the above embodiment, the case where the image data is PCM coded by the encoder has been described. However, the present invention is not limited thereto, and other coding methods such as orthogonal coding methods may be applied.

(3-5) In the above embodiment, a case is described in which a plurality of combinations are stored in the ROM for the threshold values of the frequency distribution table obtained for each layer, and a combination of the threshold values closest to the target value is generated. The present invention is not limited to this, but may be set independently for each layer.

(3-6) In the above embodiment, the average value of the lowest hierarchical data is determined by 2 lines x 2 pixels, and the upper image data is obtained. However, the present invention is not limited thereto, and the average value may be obtained by other combinations.

(4) As described above, according to the present invention, in the image encoding apparatus which sequentially divides and encodes image data into a plurality of hierarchical data having different resolutions, the transmission data including each encoded hierarchical data is transferred to a predetermined transmission path. When transmitting the data to the transmission path, the transmission data is divided into fixed length data and variable length data for each predetermined unit forming an image, and the fixed length data is sent to the transmission path and then the variable length data is sent to the transmission path. In this case, even when an error occurs in the variable length data, the content of the fixed wavelength data can be accurately detected, thereby realizing an image encoding apparatus and a data transmission method having robustness against errors in the transmission data.

1 is a block diagram showing a picture coding apparatus using a conventional pyramid coding method.

2 is a block diagram showing a picture decoding apparatus to which the picture coding apparatus of FIG. 1 is applied.

3 is a schematic diagram illustrating the principle of hierarchical coding according to the present invention.

4 is a diagram of adaptive segmentation results in HD standardization using the hierarchical coding principle of FIG.

5 is a diagram showing the standard deviation of the signal level of each layer in HD standardization using the layer coding principle of FIG.

6 is a block diagram of a first embodiment of a picture coding apparatus according to the present invention;

7 is a schematic diagram showing the structure of hierarchical data in hierarchical coding.

8 is a block diagram showing the picture coding apparatus of the first embodiment.

9 is a block diagram showing another embodiment of the first embodiment;

10 is a block diagram showing a second embodiment of a picture coding apparatus according to the present invention.

11 is a block diagram showing a third embodiment of a picture coding apparatus according to the present invention;

12 is a block diagram showing the hierarchical encoding encoder of FIG.

13 is a block diagram showing the decoder of FIG.

14 is a block diagram showing the encoder of FIG.

15 is a schematic diagram illustrating a hierarchical structure.

16 is a block diagram showing a generation information amount control unit.

17 is a characteristic curve diagram showing a frequency distribution table of each layer.

18 is a table showing the combination of thresholds obtained for each layer.

19 is a characteristic curve diagram showing a frequency distribution table.

20 is a characteristic curve diagram showing an integrated frequency distribution table.

21 is a characteristic curve diagram showing a frequency distribution table.

22 is a characteristic curve diagram showing an integrated frequency distribution table.

23 is a block diagram showing a fourth embodiment of a picture coding apparatus according to the present invention.

FIG. 24 is a block diagram showing the hierarchical encoding encoder of FIG.

25 is a block diagram showing the encoder of FIG.

26 is a block diagram showing a generation information amount control section.

Fig. 27 is a characteristic curve diagram showing the frequency distribution table of each layer.

28 is a characteristic curve diagram showing an example of the frequency distribution table.

29 is a characteristic curve diagram showing an example of the frequency distribution table.

30 is a characteristic curve diagram showing an example of the frequency distribution table.

31 is a characteristic curve diagram showing a frequency distribution table.

32 is a characteristic curve diagram showing an integrated frequency distribution table.

33 is a characteristic curve diagram showing a frequency distribution table using clipped values.

34 is a characteristic curve diagram showing an integrated frequency distribution table using clipped values.

35 is a flowchart showing a processing sequence of hierarchical encoding.

36 is a block diagram showing a fifth embodiment of the picture coding apparatus according to the present invention.

37 is a block diagram showing the hierarchical encoding encoder of FIG. 36;

FIG. 38 is a block diagram showing an encoder of FIG. 37. FIG.

39 is a block diagram showing a generation information amount control section.

40 is a characteristic curve diagram showing a frequency distribution table of each layer.

41 is a characteristic block diagram showing an example of a frequency distribution table.

42 is a characteristic block diagram showing an example of a frequency distribution table.

43 is a characteristic block diagram showing an example of a frequency distribution table.

44 is a characteristic block diagram showing a frequency distribution table.

45 is a characteristic block diagram showing an integrated frequency distribution table.

46 is a characteristic block diagram showing a frequency distribution table using clipped values.

Fig. 47 is a characteristic block diagram showing an integrated frequency distribution table using clipped values.

48 is a flowchart showing a hierarchical encoding process.

49 is a block diagram showing a sixth embodiment of a picture coding apparatus according to the present invention.

FIG. 50 is a block diagram showing the hierarchical encoding encoder of FIG. 49; FIG.

51 is a block diagram showing an encoder of FIG. 50;

52 is a schematic diagram providing a description of a hierarchical structure.

Fig. 53 is a signal waveform diagram showing a result of division of a color signal.

54 is a flowchart showing a hierarchical encoding process.

55 is a block diagram showing a seventh embodiment of an image encoding device according to the present invention.

56 is a conceptual plan view showing the data structure of a transport block.

* Explanation of symbols for main parts of the drawings

40, 80, 90, 100, 110A: Hierarchical Encoding Device

40A, 80A, 90A, 100A: Hierarchical Encoding Encoder

40B, 80B, 90B, 100B: Generation information amount control part

51-55, 154-158: encoder

56-59, 161-165: A decoder

52C, 53C, 54C, 54F, 65 to 68: activity detection circuit

69 to 73: Frequency distribution table

74: control unit

111: transport block forming unit

120: fixed-length data block

121: Variable length data block

122: transport block

140: image coding device

150 to 153, 170 to 173: split control circuit

159: control code generation circuit

166: control code analysis circuit

D31, D131: input image data

D31 to D35 and D131 to D135: hierarchical data

D41 to D44, D140 to D143: Difference data

D51, D145: First layer encoded data

D52, D146: second layer encoded data

D53, D147: Third layer coded data

D54, D148: Fourth layer encoded data

D55, D149: Fifth layer encoded data

D57, S1: Optimal Control Value

J1 to J4D: Threshold determination result information

C1 to C6: control signal

TH1-TH4: Threshold

C1: transport block identification code

C2: data division determination code between layers

Detailed description of the invention

The picture coding apparatus and method of the present invention can be used as a transmitter of a system having a monitor having a different resolution on the receiving side, such as a television conference system or a video on demand system.

Claims (52)

A picture coding apparatus for encoding an input picture signal recursively to generate a plurality of hierarchical data having different resolutions, An adaptive block division method corresponding to the nature of image data, the method comprising detecting block activity of a predetermined block of each layer data and determining whether the block or a lower block corresponding thereto is divided according to the detected value. Determination division means for dividing the image data in accordance with the determination result; And transmitting means for transmitting the hierarchical coded data obtained by the decision dividing means. An image encoding apparatus for encoding an input image signal to sequentially generate a plurality of hierarchical data having a plurality of different resolutions, Detecting a block activity of a predetermined block of each layer data except for the highest layer data having the lowest resolution, and generating a segmentation determination flag for determining a partitioning method of a block corresponding to the block based on the block activity; And generating a partition stop flag for stopping division of the plurality of lower blocks corresponding to the block when a determination result indicating that the block activity is smaller than a predetermined threshold is obtained. Determination control means for generating a control signal for determining the block activity of and stopping transmission of the hierarchical data of the plurality of lower blocks; And transmission means for transmitting the determination flag for each block together with the encoded respective hierarchical data. In order to sequentially generate a plurality of hierarchical data having a plurality of different resolutions, the input image signal is a difference between the highest hierarchical data having the lowest resolution and each hierarchical data except the highest hierarchical data and adjacent high hierarchical data. An image encoding apparatus for encoding hierarchical differential data of a plurality of layers, Detecting a block activity of a predetermined block of the inter-layer difference data of each layer except the uppermost layer, and generating a segmentation determination flag for determining a partitioning method of a block corresponding to the block based on the block activity. And generating a partition stop flag for stopping division of the plurality of lower blocks corresponding to the block when a determination result indicating that the block activity is smaller than a predetermined threshold is obtained. Determination control means for generating a control signal for determining the block activity of and stopping transmission of the hierarchical data of the plurality of lower blocks; And transmission means for transmitting the determination flag for each block together with the encoded highest layer data and each encoded layer data. An image encoding apparatus for encoding an input image signal to sequentially generate a plurality of hierarchical data having a plurality of different resolutions, Detecting a block activity of a predetermined block of each layer data except for the highest layer data having the lowest resolution, and generating a segmentation determination flag for determining a segmentation of a block corresponding to the block based on the block activity; Further, when a determination result indicating that the block activity is smaller than a predetermined threshold is obtained, a partition abort flag for temporarily stopping division of a plurality of sub-blocks corresponding to the block is generated, and the plurality of sub-blocks Determination control means for changing the division stop flag to a division continuation flag for continuing division when a determination result indicating that the block activity of at least one block of the block is equal to or greater than a predetermined threshold is obtained; And transmission means for transmitting the determination flag for each block together with the encoded respective hierarchical data. In order to sequentially generate a plurality of hierarchical data having a plurality of different resolutions, the input image signal is a difference between the highest hierarchical data having the lowest resolution and each hierarchical data except the highest hierarchical data and adjacent high hierarchical data. An image encoding apparatus for encoding hierarchical differential data of a plurality of layers, Detecting a block activity of a predetermined block of the inter-layer difference data of each layer except the top layer, and generating a segmentation determination flag for determining the division of a block corresponding to the block based on the block activity; And temporarily generating a division stop flag for stopping division of the plurality of lower blocks corresponding to the block when a determination result indicating that the block activity is smaller than a predetermined threshold is obtained. Determination control means for changing the division stop flag to the division continuation flag when a determination result indicating that the block activity of at least one block of a lower block is equal to or greater than a predetermined threshold value is obtained; And transmission means for transmitting the determination flag for each block together with the encoded highest layer data and each encoded layer data. An image encoding apparatus for encoding an input image signal to sequentially generate a plurality of hierarchical data having a plurality of different resolutions, Detecting the block activities of all blocks of each layer data except the highest layer data having the lowest resolution, generating a segmentation determination flag for determining the partitioning of each block based on the block activities, and further generating the block activity flag. When a determination result indicating that the activity is smaller than a predetermined threshold is obtained, a division stop flag for stopping the division of the block is generated, and a determination result indicating that the block activity is above a predetermined threshold is obtained. Determination control means for generating a division continuation flag for continuing division of said block; And transmission means for transmitting the determination flag for each block together with the encoded respective hierarchical data. In order to generate a plurality of hierarchical data having a plurality of different resolutions sequentially recursively, a plurality of input image signals are the difference between the highest hierarchical data having the lowest resolution and each hierarchical data except the highest hierarchical data and the adjacent high hierarchical data. In the image encoding device for encoding hierarchical difference data of a layer, Detecting a block activity of all blocks of the inter-layer difference data of each layer except for the highest layer, and generating a segmentation determination flag for determining the division of each block based on the block activity; When a determination result indicating that the block activity is smaller than a predetermined threshold is obtained, a segmentation stop flag for stopping division of the block is generated, and a determination result indicating that the block activity is above a predetermined threshold is obtained. Determination control means for generating a division continuation flag for continuing division of the block when it goes down; And transmission means for transmitting the determination flag for each block together with the encoded highest layer data and each encoded layer data. The method of claim 2, And hierarchical data forming means for forming the upper hierarchical data by weighting the lower hierarchical data. The method of claim 3, wherein And the hierarchical difference data is difference data between the hierarchical data and n-1 lower hierarchical data. The method of claim 2, A maximum value, an average value, an absolute value, a standard deviation, and an n sum are used as the activity. The method of claim 2, And the data having a value exceeding a predetermined threshold is used as the activity. The method of claim 2, And the threshold value is set to a value different for each layer. In order to generate a plurality of hierarchical data having a plurality of different resolutions recursively, an image encoding apparatus for encoding an input image signal composed of a plurality of image forming signals having mutual relations to form an image, For a predetermined block of the hierarchical data except for the lowest hierarchical data having the lowest resolution, a block activity corresponding to a first signal is detected among the plurality of image forming signals, and based on the block activity, Generating a segmentation decision flag for determining a segmentation of a block or a lower block corresponding to the block, and when a determination result indicating that the block activity is smaller than a predetermined threshold is obtained; Division for continuing division of the block or the lower block corresponding to the block when a determination result indicating that the block activity is equal to or greater than a predetermined threshold is obtained while generating a division stop flag for stopping division of the lower block. Continue to generate a flag, and the threshold is set to the plurality of image signals And determination control means for determining on the basis of the second signal in the picture. The method of claim 13, And wherein the first signal is a color signal, and the second signal is a luminance signal. The method of claim 14, And the first signal is an RGB signal. An image encoding apparatus for encoding an input image signal to sequentially generate a plurality of hierarchical data having a plurality of different resolutions, Threshold detection means for detecting a threshold which is a determination criterion of the block activity based on the block activities of all blocks of the hierarchical data in order to control the amount of generated information to a target value; A block activity of a predetermined block of each layer data except for the highest layer data having the lowest resolution is detected, and a partitioning scheme of the block or the block corresponding to the block is based on a result of comparing the block activity with the threshold value. Determination dividing means for dividing and determining And transmitting means for transmitting the hierarchical coded data obtained from said decision dividing means. An image encoding apparatus for encoding an input image signal to sequentially generate a plurality of hierarchical data having a plurality of different resolutions, The block activity of the predetermined block of each layer data except the highest layer data having the lowest resolution and the threshold value as a criterion for determining the block activity correspond to each block activity for each layer detected based on the block activity. Threshold detection means for detecting on the basis of the distribution state of block frequency to be performed; Detecting a block activity of a predetermined block of each layer data except for the highest layer data having the lowest resolution, and generating a segmentation determination flag for determining a partitioning method of a block corresponding to the block based on the block activity; And generating a partition stop flag for stopping division of the plurality of lower blocks corresponding to the block when a determination result indicating that the block activity is smaller than a predetermined threshold is obtained. Determination control means for generating a control signal for determining the block activity of and stopping transmission of the hierarchical data of the plurality of lower blocks; And means for transmitting the decision flag for each block together with the encoded respective hierarchical data. In order to sequentially generate a plurality of hierarchical data having a plurality of different resolutions, the input image signal is a difference between the highest hierarchical data having the lowest resolution and each hierarchical data except the highest hierarchical data and adjacent high hierarchical data. An image encoding apparatus for encoding hierarchical differential data of a plurality of layers, The block activity of the predetermined block of each layer data except the highest layer data having the lowest resolution and the threshold value as a criterion for determining the block activity are assigned to each block activity for each layer detected based on the block activity. Threshold detection means for detecting based on a distribution state of corresponding block powers; Detecting a block activity of a predetermined block of the inter-layer difference data of each layer except the uppermost layer, and generating a segmentation determination flag for determining a partitioning method of a block corresponding to the block based on the block activity. And generating a partition stop flag to stop division of the plurality of lower blocks corresponding to the block when a determination result indicating that the block activity is smaller than a predetermined threshold is obtained. Decision control means for generating a control signal for stopping the determination of the block activity of the block and the transmission of the hierarchical data of the plurality of lower blocks; And transmission means for transmitting the determination flag for each block together with the encoded highest layer data and each encoded layer data. An image encoding apparatus for encoding an input image signal to sequentially generate a plurality of hierarchical data having a plurality of different resolutions, The block activity of the predetermined block of each layer data except the highest layer data having the lowest resolution and the threshold value as a criterion for determining the block activity correspond to each block activity for each layer detected based on the block activity. Threshold detection means for detecting on the basis of the distribution state of block frequency to be performed; Detecting a block activity of a predetermined block of each layer data except for the highest layer data having the lowest resolution, and generating a segmentation determination flag for determining a segmentation of a block corresponding to the block based on the block activity; Further, when a determination result indicating that the block activity is smaller than a predetermined threshold is obtained, a partition abort flag for temporarily stopping division of a plurality of sub-blocks corresponding to the block is generated, and the plurality of sub-blocks Determination control means for changing the division stop flag to a division continuation flag for continuing division when a determination result indicating that the block activity of at least one block of the block is equal to or greater than a predetermined threshold is obtained; And transmission means for transmitting the determination flag for each block together with each of the encoded hierarchical data. In order to generate a plurality of hierarchical data having a plurality of different resolutions sequentially recursively, the input image signal has a plurality of differences between the highest hierarchical data having the lowest resolution and each hierarchical data except the highest hierarchical data and adjacent high hierarchical data. In the image encoding device for encoding hierarchical difference data of a layer, The block activity of a predetermined block of each layer data except the highest layer data having the lowest resolution and a threshold that is a criterion for determining the block activity correspond to each block activity for each layer detected based on the block activity. Threshold detection means for detecting on the basis of the distribution state of block frequency to be performed; A block determination flag for detecting a block activity of a predetermined block of the inter-layer difference data of each layer except for the highest layer, and for determining a manner of dividing a block corresponding to the block based on the block activity; And a partition abort flag for temporarily stopping division of a plurality of sub-blocks corresponding to the block when a determination result indicating that the block activity is smaller than a predetermined threshold is obtained. Determination control means for changing the division stop flag to a division continuation flag when a determination result indicating that the block activity of at least one block of the lower block of is greater than or equal to a predetermined threshold is obtained; And transmission means for transmitting the determination flag for each block together with the encoded highest layer data and each encoded layer data. An image encoding apparatus for encoding an input image signal to sequentially generate a plurality of hierarchical data having a plurality of different resolutions, The block activity of the predetermined block of each layer data except the highest layer data having the lowest resolution and the threshold value as a criterion for determining the block activity correspond to each block activity for each layer detected based on the block activity. Threshold detection means for detecting on the basis of a distribution state of block powers; Detecting a block activity of all blocks of each layer data except the highest layer data having the lowest resolution, and generating a segmentation determination flag for determining a partitioning scheme of each block based on the block activity; When a determination result indicating that the block activity is smaller than a predetermined threshold is obtained, a division stop flag for stopping division of the block is generated, and a determination result indicating that the block activity is above a predetermined threshold is generated. Decision control means for generating a division continuation flag for continuing division of the block when obtained; And transmission means for transmitting the determination flag for each block together with each of the encoded hierarchical data. In order to generate a plurality of hierarchical data having a plurality of different resolutions sequentially recursively, a plurality of input image signals are used as the difference between the highest hierarchical data having the lowest resolution and each hierarchical data except the highest hierarchical data and adjacent high hierarchical data. In the image encoding device for encoding hierarchical difference data of a layer, The block activity of the predetermined block of each layer data except the highest layer data having the lowest resolution and the threshold value as a criterion for determining the block activity are assigned to each block activity for each layer detected based on the block activity. Threshold detection means for detecting based on a distribution state of corresponding block powers; Detecting a block activity of all blocks of the inter-layer difference data of each layer except for the highest layer, and generating a segmentation determination flag for determining a partitioning scheme of each block based on the block activity; When a determination result indicating that the block activity is smaller than a predetermined threshold is obtained, a segmentation stop flag for stopping division of the block is generated, and a determination result indicating that the block activity is above a predetermined threshold is obtained. Determination control means for generating a division continuation flag for continuing division of the block when it goes down; And transmission means for transmitting the determination flag for each block together with the encoded highest layer data and each encoded layer data. The method of claim 17, And the threshold value is detected based on a history of the block activity in an upper layer. The method of claim 19, And the threshold value is detected based on a history of the block activity in a lower layer. The method of claim 17, And controlling the input data to a standby state, and hierarchically encoding the input data at a time when the threshold is determined. The method of claim 17, And the threshold value is determined independently for each of the layers. The method of claim 17, And a combination of the thresholds for each of the layers in advance. The method of claim 17, And an integrated frequency distribution table for calculating the amount of generated information. The method of claim 17, And the number of block activities is limited to a predetermined limit when calculating the amount of occurrence information. The method of claim 28, And a different limiting value for the number of block activities for each of said hierarchies when generating an integrated frequency distribution table. A picture coding apparatus for encoding an input picture signal recursively to generate a plurality of hierarchical data having a plurality of different resolutions, An adaptive block division method corresponding to the property of image data, the block activity of a predetermined block of each hierarchical data is detected, and it is determined whether or not the block or a lower block corresponding thereto is divided according to the detected value. Determination dividing means for dividing the image data in accordance with a result; And transmitting means for transmitting the variable length data after the fixed length data is transmitted to the hierarchical coded data obtained by the determining means. The method of claim 31, wherein And said fixed length data is comprised of said top layer data and image formation information for forming said respective layer data, and said variable length data is comprised of said each layer data except said top layer. The method of claim 32, And the hierarchical coded data includes a segmentation determination flag. A picture coding apparatus for encoding an input picture signal recursively to generate a plurality of hierarchical data having a plurality of different resolutions, An adaptive block division method corresponding to the property of image data, the block activity of a predetermined block of each hierarchical data is detected, and it is determined whether or not the block or a lower block corresponding thereto is divided according to the detected value. Determination dividing means for dividing the image data in accordance with a result; And transmitting means for transmitting the highest hierarchical data obtained from the determining means as fixed length data and then transmitting each hierarchical data except for the highest hierarchical data as variable length data. The method of claim 34, wherein And the fixed length data includes a segmentation determination flag. In the image coding method of encoding an input image signal recursively to generate a plurality of hierarchical data having different resolutions, An adaptive block division method corresponding to the property of image data, the block activity of a predetermined block of each hierarchical data is detected, and it is determined whether or not the block or a lower block corresponding thereto is divided according to the detected value. Determination dividing means for dividing the image data in accordance with a result; And transmitting the hierarchical coded data obtained from the decision dividing step. An image encoding method of encoding an input image signal in order to generate a plurality of hierarchical data having a plurality of different resolutions sequentially recursively, A block activity of a predetermined block of each layer data except for the highest layer data having the lowest resolution is detected, and a segmentation determination flag is generated for determining a partitioning method of a block corresponding to the block based on the block activity. And generating a partition stop flag for stopping division of the plurality of lower blocks corresponding to the block when a determination result indicating that the block activity is smaller than a predetermined threshold is obtained. Generating a control signal for determining the block activity of the block and for stopping the transmission of the hierarchical data of the plurality of lower blocks, And a decision flag for each block is transmitted together with the encoded hierarchical data. In order to generate a plurality of hierarchical data having a plurality of different resolutions sequentially recursively, a plurality of input image signals are used as the difference between the highest hierarchical data having the lowest resolution and each hierarchical data except the highest hierarchical data and adjacent high hierarchical data. In the image encoding method for encoding hierarchical difference data of a layer, A block determination flag for detecting a block activity of a predetermined block of the inter-layer difference data of each layer except for the highest layer, and for determining a manner of dividing a block corresponding to the block based on the block activity; Is generated, and when a determination result indicating that the block activity is smaller than a predetermined threshold is obtained, a division stop flag for stopping division of the plurality of lower blocks corresponding to the block is generated, and Generating a control signal for determining the block activity of the block and for stopping transmission of the hierarchical data of the plurality of lower blocks; And the determination flag for each block is transmitted together with the encoded highest layer data and each encoded layer data. In the image encoding method of encoding an input image signal in order to generate a plurality of hierarchical data having a plurality of different resolutions recursively, Detecting a block activity of a predetermined block of the hierarchical data except for the lowest hierarchical data having a lowest resolution, and generating a division determination flag for determining a division method of a block corresponding to the block based on the block activity; And when a determination result indicating that the block activity is smaller than a predetermined threshold is obtained, a partition abort flag for temporarily stopping division of the plurality of lower blocks corresponding to the block is generated. When the determination result indicating that the block activity of at least one block of the block is greater than or equal to a predetermined threshold is obtained, change the split stop flag to a split continue flag to continue splitting, And the determination flag for each block is transmitted together with the encoded hierarchical data. In order to generate a plurality of hierarchical data having a plurality of different resolutions sequentially recursively, a plurality of input image signals are used as the difference between the highest hierarchical data having the lowest resolution and each hierarchical data except the highest hierarchical data and adjacent high hierarchical data. In the image encoding method for encoding hierarchical difference data of a layer, Detecting a block activity of a predetermined block of the inter-layer difference data of each layer except the uppermost layer, and generating a segmentation determination flag for determining a partitioning method of a block corresponding to the block based on the block activity. And when a determination result indicating that the block activity is smaller than a predetermined threshold is obtained, temporarily generating a segmentation stop flag for stopping the division scheme of the plurality of lower blocks corresponding to the block. When the determination result indicating that the block activity of at least one block of a plurality of lower blocks is equal to or greater than a predetermined threshold is obtained, change the split stop flag to a split continue flag; And the determination flag for each block is transmitted together with the encoded highest layer data and each encoded layer data. In the image encoding method of encoding an input image signal in order to generate a plurality of hierarchical data having a plurality of different resolutions recursively, Detecting a block activity of all blocks of each layer data except the highest layer data having the lowest resolution, and generating a segmentation determination flag for determining a manner of partitioning of each block based on the block activity; When a determination result indicating that the block activity is smaller than a predetermined threshold is obtained, a division stop flag for stopping division of the block is generated, and a determination result indicating that the block activity is above a predetermined threshold is generated. Generate a continue segmentation flag to continue partitioning of the block when obtained, And the determination flag for each block is transmitted together with the encoded hierarchical data. In order to sequentially generate a plurality of hierarchical data having a plurality of different resolutions, the input image signal is a difference between the highest hierarchical data having the lowest resolution and each hierarchical data except the highest hierarchical data and adjacent high hierarchical data. An image encoding method for encoding hierarchical difference data of a plurality of layers, Detecting a block activity of all blocks of the inter-layer difference data of each layer except the highest layer, and generating a segmentation determination flag for determining a manner of partitioning of each block based on the block activity, Further, when a determination result indicating that the block activity is smaller than a predetermined threshold is obtained, a division stop flag for stopping division of the block is generated, and a determination result indicating that the block activity is equal to or greater than a predetermined threshold. Generates a continue segmentation flag to continue partitioning of the block when And the determination flag for each block is transmitted together with the encoded highest layer data and each encoded layer data. In order to generate a plurality of hierarchical data having a plurality of different resolutions recursively, an image encoding method for encoding an input image signal composed of a plurality of image forming signals having mutual relations to form an image, A block activity corresponding to a first signal of the plurality of image forming signals is detected for a predetermined block of each layer data except for the highest layer data having the lowest resolution, and the block or the block is based on the block activity. Generating a segmentation decision flag for determining a manner of partitioning of the block corresponding to, and when a determination result indicating that the block activity is smaller than a predetermined threshold is obtained, A segmentation continuation flag for continuing segmentation of the block or a lower block corresponding to the block when a decision result indicating that the block activity is above a predetermined threshold is obtained while generating a segmentation stop flag for stopping the segmentation. Is generated, and the threshold value is selected from the plurality of image forming signals. The picture coding method, characterized in that determining on the basis of the second signal. An image encoding method of encoding an input image signal in order to generate a plurality of hierarchical data having a plurality of different resolutions sequentially recursively, In order to control the amount of generated information to a target value, a threshold value, which is a criterion for determining block activity, is detected based on the block activities of all blocks of the layer data. The block activity of a predetermined block of each layer data except for the highest layer data having the lowest resolution is detected, and based on a result of comparing the block activity with the threshold value, the block or lower block corresponding to the block is detected. The division method is determined and divided. And the hierarchical coded data obtained from the decision dividing means. In the image encoding method of encoding an input image signal in order to generate a plurality of hierarchical data having a plurality of different resolutions recursively, The block activity of the predetermined block of each layer data except the highest layer data having the lowest resolution and the threshold value as a criterion for determining the block activity correspond to each block activity for each layer detected based on the block activity. Detection based on the distribution of block frequency Block activity of a predetermined block of each layer data except for the highest layer data having the lowest resolution is detected, and a segmentation determination flag is generated for determining a partitioning method of a block corresponding to the block based on the block activity. And generating a partition stop flag for stopping division of the plurality of lower blocks corresponding to the block when a determination result indicating that the block activity is smaller than a predetermined threshold is obtained. Generating a control signal for determining the block activity of the block and for stopping transmission of the layer data of the plurality of lower blocks, And the determination flag for each block is transmitted together with the encoded hierarchical data. In order to generate a plurality of hierarchical data having a plurality of different resolutions sequentially recursively, a plurality of input image signals are used as the difference between the highest hierarchical data having the lowest resolution and each hierarchical data except the highest hierarchical data and adjacent high hierarchical data. In the image encoding method for encoding hierarchical difference data of a layer, The block activity of the predetermined block of each layer data except the highest layer data having the lowest resolution and a threshold value as a criterion for determining the block activity correspond to each block activity for each layer detected based on the block activity. Detecting based on the distribution state of the block frequency, Detecting a block activity value of a predetermined block of the inter-layer difference data of each layer except for the uppermost layer, and generating a partition determination flag for determining a partitioning method of a block corresponding to the block based on the block activity value. , When a determination result indicating that the block activity is smaller than a predetermined threshold is obtained, a segmentation stop flag for stopping division of the plurality of lower blocks corresponding to the block is generated, and the blocks of the plurality of lower blocks are generated. Generating a control signal for determining activity and for stopping transmission of hierarchical data of the plurality of lower blocks; And the determination flag for each block is transmitted together with the encoded highest layer data and each encoded layer data. An image encoding method of encoding an input image signal in order to generate a plurality of hierarchical data having a plurality of different resolutions sequentially recursively, The block activity of the predetermined block of each layer data except the highest layer data having the lowest resolution and the threshold value as a criterion for determining the block activity correspond to each block activity for each layer detected based on the block activity. Detecting based on the distribution state of one block frequency, Detecting a block activity value of a predetermined block of each layer data except for the highest layer data having the lowest resolution; A partition for continuing to divide the partition stop flag when the decision to indicate that the block activity of at least one block of the plurality of lower blocks is equal to or greater than a predetermined threshold is obtained while temporarily generating a partition stop flag; Keep changing to the flag, And the determination flag for each block is transmitted together with the encoded hierarchical data. In order to generate a plurality of hierarchical data having a plurality of different resolutions sequentially recursively, the input image signal includes a plurality of difference values between the highest hierarchical data having the lowest resolution and each hierarchical data except the highest hierarchical data and adjacent high hierarchical data. In the image encoding method for encoding hierarchical difference data of a layer, The block activity of the predetermined block of each layer data except the highest layer data having the lowest resolution and the threshold value as a criterion for determining the block activity correspond to each block activity for each layer detected based on the block activity. Based on the distribution of block frequency Detecting a segmentation activity of a predetermined block of the inter-layer difference data of each layer except the top layer, and generating a segmentation determination flag for determining a segmentation of a block corresponding to the block based on the block activity; And temporarily generating a division stop flag for stopping division of a plurality of lower blocks corresponding to the block when a determination result indicating that the block activity is smaller than a predetermined threshold is obtained. When the determination result indicating that the block activity of at least one block of the lower block is equal to or greater than a predetermined threshold is obtained, change the split stop flag to a split continue flag; And the determination flag for each block is transmitted together with the encoded highest layer data and each encoded layer data. An image encoding method of encoding an input image coral to sequentially generate a plurality of hierarchical data having a plurality of different resolutions recursively, The block activity of the predetermined block of each layer data except the highest layer data having the lowest resolution and the threshold value as a criterion for determining the block activity correspond to each block activity for each layer detected based on the block activity. Detecting based on the distribution state of one block frequency, Detecting a block activity of all blocks of each layer data except the highest layer data having the lowest resolution, and generating a segmentation determination flag for determining a partitioning scheme of each block based on the block activity; When a determination result indicating that the block activity is smaller than a predetermined threshold is obtained, a segmentation stop flag for stopping division of the block is generated, and a determination result indicating that the block activity is above a predetermined threshold is obtained. Generate a segmentation continuation flag to continue segmentation of the block when And the determination flag for each block is transmitted together with the encoded hierarchical data. In order to generate a plurality of hierarchical data having a plurality of different resolutions sequentially recursively, a plurality of input image signals are used as the difference between the highest hierarchical data having the lowest resolution and each hierarchical data except the highest hierarchical data and adjacent high hierarchical data. In the image encoding method for encoding hierarchical difference data of a layer, The block activity of the predetermined block of each layer data except the highest layer data having the lowest resolution and the threshold value as a criterion for determining the block activity correspond to each block activity for each layer detected based on the block activity. Detecting based on the distribution state of one block frequency, Detecting a block activity of all blocks of the inter-layer difference data of each layer except for the highest layer, and generating a segmentation determination flag for determining a partitioning scheme of each block based on the block activity; When a determination result indicating that the block activity is smaller than a predetermined threshold is obtained, a division stop flag for stopping division of the block is generated, and a determination result indicating that the block activity is above a predetermined threshold is generated. Generate a continue segmentation flag to continue partitioning of the block when obtained, And the determination flag for each block is transmitted together with the encoded highest layer data and each encoded layer data. An image encoding method of encoding an input image signal recursively to generate a plurality of hierarchical data having different resolutions, An adaptive block division method corresponding to the property of image data, the block activity of a predetermined block of each hierarchical data is detected, and it is determined whether or not the block or a lower block corresponding thereto is divided according to the detected value. The image data is divided according to the result, The variable length data is transmitted after the fixed length data is transmitted to the hierarchical coded data obtained on the basis of the determination result. In the image encoding method of encoding an input image signal recursively to generate a plurality of hierarchical data having a plurality of different resolutions, An adaptive block division method corresponding to the property of image data, the block activity of a predetermined block of each hierarchical data is detected, and it is determined whether or not the block or a lower block corresponding thereto is divided according to the detected value. The image data is divided according to the result, And transmitting the highest hierarchical data obtained based on the determination result as fixed length data, and then transmitting each hierarchical data except the highest hierarchical data as variable length data.