JPH0738858A - Transmission equipment and reception equipment for digital image signal - Google Patents

Abstract

PURPOSE:To obtain a beautiful reproduced image even by a transmission medium with a low transmission rate and make the motion of the image smooth by transmitting background information in a wider range than a picture frame reproduced as one screen as background on a still picture. CONSTITUTION:A background plane memory means 23 stores background plane information consisting of a background still picture constituting a screen and moving body plane memory means 23A1-23An individually store one-plural pieces of moving body plane information consisting of respective still pictures of a moving body. A variation information detecting means 22 detects variation information on the still pictures stored as the moving body plane information based on the input digital image signal and respective memory outputs and the detection output is compressed and encoded 26. The pieces of still picture information and encoded variation information are supplied to transmitting means 25 and 27. Then the background information in the wider range than the picture frame reproduced as one screen is stored in a memory 23GB as background plane information and sent as still pictures.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital image signal transmitting apparatus and its receiving apparatus.

[0002]

2. Description of the Related Art It is general to use an image pickup apparatus to focus only on a subject for the purpose of main shooting.
The background is not taken into account when shooting. Therefore, conventionally, only a reproduced image with the composition determined at the time of shooting can be obtained.

[0003]

However, there are many demands for changing the position of the background during reproduction. However,
Conventionally, there is no technical means to meet this demand.

A first object of the present invention is to provide a digital image signal transmitting apparatus which can meet this demand.

A second object of the present invention is to realize an invention that meets the above-mentioned requirements, even with a transmission medium having a low transmission rate.

That is, the digital image data of a moving image contains a very large amount of information, and if it is transmitted as it is, the transmission bit rate becomes very high. For this reason, when recording and reproducing digital image data using a magnetic tape or a magneto-optical disk, when transmitting using a low-rate transmission medium whose transmission bit rate is limited, conventionally, Typically,
Data compression is performed by utilizing the fact that images are spatiotemporal information.

For example, a difference between frames of digital image data is obtained, and the difference is compressed by DCT (discrete cosine transform (discrete cosine transform)), and the digital image data is compressed and transmitted. This is conventionally done. Furthermore, in video conferencing, etc., in consideration of the fact that the image does not move much, it is necessary to thin out the amount of information, such as transmitting only one-field data instead of transmitting a full frame. And so on.

[0008] The number of fields to be transmitted is reduced instead of one field to sacrifice the time information and the spatial information is secured, so that the image is beautiful but the motion may be jerky.

However, if the motion is jerky in this way, the goodness of the moving image is impaired. Therefore, the image data per frame is compressed as much as possible to transmit the full frame, but the spatial resolution is sacrificed. A method of enabling full-motion playback as a video is also being considered.

As described above, the conventional digital image signal transmission method is devised to reduce the transmission rate by compressing image data in the time direction or the space direction. However, when the transmission bit rate is reduced only by data compression, for example, when compressed in the time direction, the motion of the moving image becomes jerky and becomes an unnatural image. Further, when compressed in the spatial direction, the spatial resolution is deteriorated to that extent, so that the reproduced image is deteriorated.

That is, in the conventional method, since the bit rate is reduced only by the data compression, one or both of the data in the time direction and the space direction is sacrificed, and the reproduced image is satisfactory. It was hard to get anything.

Therefore, according to the present invention, even if the transmission medium has a low transmission rate, a digital image signal transmission device and its reception device are devised so as to obtain a beautiful reproduced image as much as possible and at the same time make the movement smooth. Provide a device.

[0013]

In order to solve the above problems, a digital image signal transmission apparatus according to the present invention uses a screen as a still image information of a background image and information of a moving object moving on the background image. In the transmission device of the digital image signal which is transmitted separately, the background information of the still image is transmitted as background image information in a range wider than the image frame reproduced as one screen.

Further, the digital image signal transmitting apparatus according to the present invention, in order to enable transmission on a transmission medium having a low bit rate, when the reference symbols of the embodiments described later are made to correspond to each other, the background image forming the screen is frozen. Background plane memory means 23BG for storing background plane information consisting of images,
Moving object plane memory means 23A1 to 23An for individually storing one to a plurality of moving object plane information, each of which is a still image of a moving object moving on the background image.
A change information detecting means 22 for detecting change information for the still image stored as the moving object plane information based on the input digital image signal and the output of the memory means, and the output of the change information detecting means is compressed. The background plane memory means 23BG is provided with an encoding means 26 for encoding, still image information of the plurality of plane information of the memory means, and transmission means for transmitting change information from the encoding means. As the background plane information
The background information in a wider range than the image frame reproduced as one screen is stored and transmitted as the still image.

[0015]

In the present invention described above, background image information in a range wider than the image frame range reproduced as one screen is transmitted as the background plane. Therefore, on the receiving side, when loading this background plane into memory and specifying the image frame position to read from this memory, the desired background image is extracted from a wide range of background planes and played back. Images can be obtained.

Further, in the configuration of the present invention which is suitable for a transmission medium having a low transmission rate, for example, when considering one scene having specific image contents, the image of the scene is a fixed still image. And a background image that is considered to be one, and the movement is regarded as one or more different moving objects.

That is, in the present invention, one
A two-dimensional image of a frame is regarded as an overlap of a two-dimensional plane composed of a background and still images of a plurality of moving objects. Then, with respect to the moving object, change information such as the moving direction of the moving object, the moving distance, and the shape change of the object is extracted. Then, as the moving image data, the background image plane and the moving object plane are transmitted, and the change information about the moving object plane is transmitted.

On the receiving side, the moving image is reproduced by superposing the moving object of the moving object plane on the background image of the background plane according to the change information.

In this case, each of the background plane and the moving object plane is one still image, and the information of this still image only needs to be transmitted at the very beginning of one scene. Since one still image needs to be transmitted for each scene of several seconds or more, a large amount of data can be transmitted even at a low transmission rate. Therefore, the image quality is high. Since the change information may be several bits at most, it is possible to transmit the change information in real time with a margin even during the remaining time of transmitting the still image information in one scene.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a digital image signal transmitting apparatus and its receiving apparatus according to the present invention will be described below with reference to the drawings by taking a case of an apparatus for recording and reproducing a digital image signal on a magneto-optical disk as an example. explain.

The apparatus of this example is equipped with a video camera section using, for example, a CCD solid-state image pickup device, and an image signal obtained by shooting with this video camera is converted into a digital image signal by an A / D converter to generate an optical signal. It is recorded on a magnetic disk.

[Description of Disc Recording Device for Digital Image Signal] FIG. 1 shows a disc drive system and a block diagram of the device of this example. The device of this example includes a video camera section 1 and
A recording signal system 2, a system controller 3 for controlling the entire system, and a disk drive system 10 are provided, and the image pickup output signal of the video camera unit 1 is recorded via the recording signal system 2. There is.

In the disk drive system 10, 11 is a magneto-optical disk. The magneto-optical disk 11 is housed in a cartridge 11A. In addition, a pregroove for controlling a light spot (for tracking control) is formed in advance on the disk 11, and in the case of this example, the pregroove is superposed on a wobbling signal for tracking to obtain an absolute address. Data is recorded. This absolute address data is used for recording track position control at the time of this recording, and for reproduction scanning track position control at the time of reproduction described later.

The disk 11 is rotated by a spindle motor 12. The rotation of the spindle motor 12 is controlled by the servo control circuit 15, and the disk 11 is controlled so as to rotate at a constant linear velocity, for example.

The disk 11 is provided with a shutter. When the disk 11 is placed on the disk mounting tray and loaded in the apparatus, the shutter is opened. A magnetic head 13 for recording is arranged facing the upper part of the shutter opening of the disk 11, and an optical pickup 14 is arranged facing the lower part of the shutter opening of the disk 11.

The optical pickup 14 has a light emitting portion and a light receiving portion, and is controlled to move in the radial direction of the disk 11 by a feed motor 16. Further, the servo control circuit 15 controls focus and tracking of the optical pickup 14.

The system controller 3 is constructed by mounting a microcomputer and manages the entire operation. This system controller 3 has a key group 4
Gives a key input signal. The key group 4 includes an imaging / recording standby key, an imaging / recording start key, a playback key,
A stop key etc. are included.

In the case of this example, the moving image photographed by the camera unit 1 is recorded separately into a fixed background portion and a moving portion moving on the background. The fixed background portion is registered in the background plane memory 23BG described later and recorded as a still image. In the present invention, the fixed background portion is registered in the background plane 23BG with the maximum image frame that can be considered at the time of shooting.
Record as a still image.

The moving parts are separated into moving objects, and moving object plane memories 23A1 to 23A to be described later are provided.
Registered in each of n, the still image of the moving object is recorded, and the change information of the moving object of each moving object plane is recorded.

When the picked-up image is a two-dimensional image 30 as shown in FIG. 2, for example, a fixed still image composed of a stationary structure is extracted as the background plane 31 as shown in the figure. In the example of FIG. 2, an airplane, a monkey, and a car are recognized as moving objects, and they are separated as moving object planes 32, 33, and 34, respectively.

Then, in this example, as shown in FIG. 3, recording of one scene is divided into a preparation period and an actual imaging and recording period. Then, during the preparation period, the above-mentioned still image recording process of the background plane and the moving object plane is performed. During the actual image recording and recording period, only the change information of the moving object as each moving object plane is recorded.

[Recording of Preparation Period] In this case, the information for one screen is, for example, 480 lines × 72 as shown in FIG.
It is composed of 0 pixels, and the data of 1 pixel is used as the luminance signal Y.
(8 bits) and color information U, V (8 bits). In the case of this example, the moving object plane memories 23A1-2
3An can be constituted by a memory having a capacity capable of writing still picture information for one screen, but the background plane memory 23BG has, as shown in FIG. In, a large-capacity memory that can store pixel information for a plurality of screens is used. That is, the background plane memory 23BG has a capacity capable of writing pixel sample data of (480 × a) lines in the vertical direction and (720 × b) pixels in the horizontal direction. In this example,
It is assumed that a = 3 and b = 3.

Therefore, for example, when the background image at the center position in FIG. 5 is centered, the background that comes into the image frame when the camera angle is changed such as panning and tilting the camera around this center background image. Can be written in the background plane memory 23BG. Further, when the camera is zoomed at the background image at the center position, all the background images in the zoom range are written in the background plane memory 23BG. An example of a method of writing background image information in a range wider than the image frame for one screen will be described below.

In this example, first, a predetermined key of the key group 4 is operated to photograph the background plane of the maximum image frame by the camera unit 1, and then the background plane memory 2 is used.
Enter the mode for registering in 3BG. The operation in this mode will be described below.

The camera unit 1 of this example includes a zoom lens (not shown). First, the zoom is set to the widest angle side to photograph a wide background. In this example, this is the maximum image frame.

The image pickup signal from the camera unit 1 is supplied to the A / D converter 21, and for example, one pixel sample is converted into an 8-bit digital image signal, and the signal processing circuit 2 is supplied.
2 is supplied. The signal processing circuit 22 separates the image of the scene captured by the camera unit 1 into a static background stationary image that does not move and each moving object that moves on the background, and outputs the separated background image information. Register in the buffer memory. In this buffer memory, for example, as shown in FIG. 6, still image information captured with the background of the maximum image frame as one screen is obtained.

Next, with the zoom lens at the most telephoto end,
Shoot a part of the maximum image frame. In the signal processing circuit 22,
In the same manner as described above, only the fixed background portion obtained by separating the components of the moving object from the captured image (hereinafter, this is partially referred to as background image) is separated. Then, the separated partial background image is compared with the maximum image frame accumulated in the buffer memory to determine which part of the maximum image frame the background image is. In this case, assume that the size of the image frame of the partial background image is 1/9 of the maximum image frame (that is, the image frame on the most telephoto side is 1/9 of the image frame on the widest angle side). , Some background images are thinned by 1/3 in the vertical and horizontal directions,
The pattern matching is performed by comparing with the background image of the maximum image frame of the buffer memory.

Now, if it is recognized that the partial background imaged by pattern matching, for example, is the image in the upper left corner of the maximum image frame shown by hatching in FIG. The partial background image portion is written in the corresponding partial screen address of the background plane memory 23BG shown in FIG. In this case, what is written is not the thinned-out image information but the original image information.

Then, the signal processing circuit 22 stores, in the background plane memory 23BG, the position of the background image for which writing has been completed, out of the still images in the maximum image frame of FIG.

Next, while keeping the zoom lens on the most telephoto side, another partial background image within the maximum image frame is photographed. In the same manner as described above, the signal processing circuit 22 checks which part of the maximum image frame is the partial background image, and the background part which has not been written in the background plane memory 23BG corresponds to the background plane memory 23BG. Write to the address location.

The above processing is performed until all the background images of the maximum image frame are written in the background plane memory 23BG. When the writing of the maximum image frame is completed, the device notifies that by, for example, an alarm sound.

When the fixed background image of the maximum image frame is registered in the above background plane memory 23BG, it is recognized as a moving object during shooting at the maximum telephoto side and separated, for example, the airplane, monkey, car, etc. Still images of moving objects in
Each of the moving object plane memories 23A1 to 23An (n
Is a natural number).

A specific example for separating the background plane and the moving object plane will be described later.

As described above, the plane memory 23 is separated into the background plane and the plurality of moving object planes.
As described above, the image information of each still image written in the BG and 23A1 to 23An is recorded in the disk 11 in advance during the preparation period shown in FIG. 3 before the actual image pickup and recording by the video camera is started. .

In this case, the plane information for one screen is composed of 480 lines × 720 pixels as shown in FIG. 4, and the data of one pixel is the luminance signal Y and the color information U and V. Since it is composed of 16 bits, each still image information for one screen has an information amount of about 5.6 Mbits. Although the data can be recorded on the disk 11 without being compressed as it is, if the data recording rate on the disk is 1.2 Mbps, it takes about 5 seconds to record one still image. Further, in this example, the information of the background plane includes still image information for a plurality of screens, and it takes a considerable amount of time to record as it is.

Therefore, in this example, the image information written in each plane memory 23BG and 23A1-23An is supplied to the compression circuit 24, and each plane information is appropriately compressed and supplied to the recording processing circuit 25. To be done. In the recording processing circuit 25, data processing conforming to the recording format of the disk 11 is performed, for example, the data has a sector structure. The output data of the recording processing circuit 25 is sequentially supplied to the recording magnetic head 13 via the head drive circuit 27 and is magneto-optically recorded on the disk 11.

In the compression circuit 24, the data compression rate is 1/1
If it is 0, the information of four planes can be recorded with the preparation time of 2 seconds. When transmitting a full frame of moving image data with the same amount of information at 1.2 Mbps, the data compression rate is 1.
Since / 100 or more, the deterioration of the image quality of the plane information is very small compared with this.

[Actual Imaging / Recording Period] In this example, in the imaging / recording period after the actual imaging / recording start key is operated in the video camera unit 1, the moving object registered in each moving object plane is displayed. It generates motion direction and motion amount, and motion change information such as rotation and shape change.

As for the background plane, the position on the background plane memory 23BG of the image frame of the background image separated at the time of shooting and recording is set to the background plane of the image frame of the background image at the start of actual image capturing and recording. It is included in the motion change information as change information indicating the image frame position with reference to the position on the memory 23BG (hereinafter referred to as image frame position information). Then, the motion change information and the image frame position information generated as described above are recorded on the disc 11 in real time.

Therefore, in the image recording mode, the signal processing circuit 22 uses the information of the background plane and the n moving object planes separated at that time, from the input digital image signal, of each moving object plane. The motion change information of the moving object and the image frame position information of the background image are obtained. Then, the motion change information and the image frame position information are supplied to the compression encoding circuit 26, compression encoded at an appropriate compression rate, and supplied to the head drive circuit 27 via the recording processing circuit 25.

In this case, the motion change information and the image frame position information to be recorded have a small number of bits, as will be described later, and are sufficiently transmitted in real time even at a low transmission rate of 1.2 Mbps. it can. A specific example of the method for detecting the motion change information and the image frame position information will be described later.

Data is recorded on the magneto-optical disk 11 as follows. That is, the head drive circuit 2
By being supplied to the recording magnetic head 13 via 7, the magnetic field modulated by the recording data is applied at a predetermined position of the disk 11. Further, the laser beam from the optical pickup 14 is applied to the same position on the disk 11. At the time of this recording, the recording track is irradiated with laser light having a constant power larger than that at the time of reproduction. Data is recorded on the disk 11 by thermomagnetic recording by this light irradiation and the modulation magnetic field by the magnetic head 13.
The magnetic head 13 and the optical pickup 14 are both configured to be able to move in the radial direction of the disk 11 in synchronization with each other.

At the time of recording, the output of the optical pickup 14 is supplied to the address decoder 29 through the RF amplifier 28, and the absolute address wobble-recorded in the pre-groove provided along the track of the disk 11 is recorded. The data is extracted and decoded. Then, the detected absolute address data is transferred to the recording processing circuit 25.
Is supplied to the disc 11 and inserted into the recording data,
Recorded in. Further, the absolute address data is supplied to the system controller 3 and used for recognition of the recording position and position control.

The background plane information, the moving object plane information, the image frame position information, and the motion change information of each scene are recorded in the innermost circumference of the disc in which track and sector. TO to be provided
It is recorded in a disc management area called C (Table Of Contents) area.

During this recording, the signal from the RF amplifier 28 is supplied to the servo control circuit 15, and the control signal for the constant linear velocity servo of the spindle motor 12 is formed from the signal from the pre-groove of the disk 11. The spindle motor 12 is speed-controlled.

[Embodiment of Plane Separation Processing Circuit] FIG. 7
FIG. 4 is a block diagram of an embodiment of a plane separation processing circuit for separating a background plane and a plurality of moving object planes in the signal processing circuit 22.

That is, 1-pixel 8-bit image data from the A / D converter 21 through the input terminal 41 is supplied to the frame memory 42 and the subtraction circuit 44.
And the subtraction circuit 45. Further, the input image data is supplied to the moving object plane separation circuit 62 via the AND gate 61.

The frame memory 42 stores 1-pixel 8-bit data for one frame, and the subtraction circuit 44
Pixel data corresponding to the same sampling position in the previous frame is subtracted from the input pixel data. This subtraction circuit 4
The difference output of 4 is supplied to the absolute value conversion circuit 46, converted into an absolute value, and supplied to the comparison circuit 47.

The threshold value θ1 is supplied to the comparison circuit 47 through the terminal 48. When the absolute value of the difference output from the absolute value conversion circuit 46 is less than the threshold value θ1, it becomes “1”, and the threshold value θ1. In the above case, a determination output that is "0" is obtained. This determination output is supplied to the weight coefficient control circuit 49.

In FIG. 7, 23 BGs is a background plane memory having a capacity capable of storing a background image (720 pixels × 480 lines) for one screen. Memory 23BG
A background plane image (still image) is stored in s.

Reference numeral 50 is a weight coefficient memory in which the weight coefficient of one frame is stored. This weight coefficient memory 5
In 0, for example, a 3-bit weighting coefficient is stored.

Frame memory 42, background memory 23BG
The s and weight coefficient memory 50 are commonly address-controlled by the output of the address control circuit 43 so that the same address is designated.

In the subtraction circuit 45, the image data from the background plane memory 23BGs is subtracted from the input pixel data, the difference output of this subtraction circuit 45 is supplied to the absolute value conversion circuit 51, and the absolute value of the difference output is obtained. The absolute value of the difference from the absolute value conversion circuit 51 is supplied to the comparison circuit 52,
The absolute value of the difference output between the input pixel data and the background pixel data is compared with the threshold value θ2 through the terminal 53, and
From the comparison circuit 52, a determination output that becomes “1” when the value is less than 2 and becomes “0” when the threshold value θ2 or more is obtained. The determination output from the comparison circuit 52 is supplied to the weight coefficient control circuit 49.

The difference output between the input pixel data from the subtraction circuit 45 and the background pixel data is also supplied to the multiplication circuit 54 and is multiplied by the weighting coefficient α generated from the weighting coefficient control circuit 49. The multiplication output of the multiplication circuit 54 is the addition circuit 5
5 and is added to the background pixel data from the background plane memory 23BGs, and the addition output is written to the background plane memory 23BGs.

The weighting coefficient from the weighting coefficient control circuit 49 is
The weight coefficient read out from the weight coefficient memory 50 while being written in the weight coefficient memory 50 is supplied to the weight coefficient control circuit 49.

The weighting coefficient control circuit 49 determines whether the pixel data is a motion pixel from the determination outputs of the comparators 47 and 52.

In the above configuration, the background plane memory 23BGs, the subtraction circuit 45, the multiplication circuit 54, and the addition circuit 55 constitute a digital filter using the background plane memory 23BGs as a one-frame delay element.
That is, when the weighting factor is α, the input pixel data of the kth frame is Zk, and the background image data read from the background plane memory 23BGs is X (k−1), k
The background pixel data (estimated value) Xk of the frame is represented by the following equation.

Xk = α · (Zk−X (k−1)) + X (k−1) = (1−α) · X (k−1) + α · Zk In this example, one scene in which the background does not change In between, α is fixed at 1/16, for example. The white noise included in the input image is removed by repeating the operation represented by the above equation over a plurality of frames, and the S / N of the background image stored in the background plane memory 23BGs is improved.

Also, when the background changes, such as when the scene changes, that is, when the image-capturing scene changes to another image-capturing scene, the response time is shortened and the influence of colored noise is eliminated. And the weighting factor α is 1
Multiply by 2 from / 16 every frame. That is, the background image is gradually updated by using the weighting coefficient α that increases exponentially as 1/16 → 1/8 → 1/4 → 1/2 → 1. Therefore, the weighting factor α is 5
There are types, and each is represented by 3 bits.
The weighting coefficient α is set to a power of 2 because the multiplication circuit 54
This is because the shift register or the selector is realized.

In this example, after the initial state has passed, the background still image data is stored in the background plane memory 23BGs. The subtraction circuit 45 and the absolute value conversion circuit 51 detect the absolute value of the difference between the current pixel and the background pixel. The absolute value of this difference is compared with the threshold value θ2 by the comparison circuit 52, and when the absolute value of the difference is less than the threshold value θ2, it is determined that the current pixel belongs to the background image, and Processing is performed.

That is, at this time, the weighting coefficient α is 2 ⁻⁴
It is fixed at (= 1/16). Then, in the multiplication circuit 54, the output of the subtraction circuit 45 is multiplied by this weighting coefficient α, and the output of the background plane memory 23BGs and the addition circuit 5 are added.
It is added at 5. Then, the added output is written to the same address in the background plane memory 23BGs,
The background plane memory is updated. The weight coefficient at this time is written in the weight coefficient memory 50.

When the comparison circuit 52 determines that the absolute value of the difference between the current pixel and the background pixel is not less than the threshold value θ2, the current pixel detected by the subtraction circuit 44 and the absolute value conversion circuit 46 and the previous pixel are detected. Whether the absolute value of the difference from the corresponding pixel in the frame is less than the threshold value θ1 or more than the threshold value θ1 is examined as the output of the comparison circuit 47. When the output of the comparison circuit 47 is less than the threshold value θ1, the following processing is performed.

In other words, when the value is less than the threshold value θ1, the weighting coefficient α (= 1/16) stored in the weighting coefficient memory 50 is the one when the background is switched due to a scene change or the like. Is read out, and the weighting coefficient α is multiplied by the output signal of the subtraction circuit 45 by the multiplier 54. Therefore, the background pixel update made in this frame is similar to the one described above, where Xk = 15/16 · X (k−1) + 1/16 · Zk.

When the background pixel is updated, the weighting factor control circuit 49 doubles α, and it is determined whether or not the doubled new weighting factor is larger than 1. If it is smaller, this doubled weight coefficient α is stored in the weight coefficient memory 50. Starting with a weighting factor of 1/16, (1/8 → 1/4 → 1/2 →
1) and the weighting factor α changes for each frame.

The background is switched, the weighting factor α changes as described above, and the same background pixel updating process as described above does not proceed until 5 frames after α = 1. Therefore, even if the colored noise is erroneously detected as a new background pixel and undergoes the process of changing the weighting coefficient, the correct background pixel is stored. The way of changing the weighting coefficient α is set so that the responsiveness at the time of updating the background pixel is improved and the colored noise can be removed.

When the comparison circuit 47 determines that the absolute value of the difference between the current pixel and the previous frame pixel is greater than or equal to the threshold value θ1, it is determined that the current pixel is a moving pixel. In this case, the background plane memory 2
The 3BGs are not updated. The motion pixels are subjected to motion plane separation processing as described below.

In the weighting factor control circuit 49, the comparison circuit 52 detects that the absolute value of the current pixel and the background pixel is greater than or equal to the threshold value θ2, and the output of the comparison circuit 47 determines that the current pixel is the current pixel. The absolute value of the difference from the previous frame pixel is
When it is equal to or more than the threshold value θ1, it is detected as a moving pixel.

The motion pixel detection signal from the weighting coefficient control circuit 49 is supplied to the AND gate 61, and the input digital pixel data from the input terminal 41 input to this AND gate is gate-controlled. This AND gate 61
Goes high and opens when the current pixel is a motion pixel. Therefore, when the input pixel (current pixel) is not a moving pixel, the output of the AND gate 61 becomes "0",
When the input pixel is a motion pixel, the pixel data (this is data other than “0”; hereinafter, this is referred to as non-zero data) is output from the AND gate 61.

Reference numeral 62 denotes a moving object plane separation circuit, which includes a difference memory (frame memory) 62M capable of storing pixel data for one frame, and the output of the AND gate 61 is input to this memory 62M. This memory 62M receives the address control signal from the address control circuit 43, and the above-mentioned frame memory 42 and background plane memory 23BG.
It receives the same address control as the s and weight coefficient memory 50.

Therefore, the background image is removed from the current image in the difference memory 62M, and a difference image consisting of only the images of a plurality of moving objects consisting of a set of moving pixels consisting of non-zero data is stored. . And FIG.
As shown in, as data of pixels other than the non-zero pixel data of the moving object, “0” data is written in the memory 62M.

In this way, one 2
The pixel data of a plurality of moving objects in the three-dimensional image are
Written as non-zero pixel data having a level other than "0", the pixel data of the still image portion of the background image other than the pixels of the moving object is stored as all "0" data. Therefore, if a plurality of moving objects do not overlap each other, the pixel data in the difference memory 62M are sequentially scanned, and non-zero pixel data that is not "0" are associated and merged (integrated) by neighboring pixels. , It becomes possible to separate the moving object plane which consists of only each of the moving objects.

Reference numeral 63 is a microcomputer, which scans the difference memory 62M of the moving object plane separation circuit 62, separates planes for each moving object as follows, and outputs the information of the separated moving object planes to corresponding addresses. In, the data is written in each of the moving object plane memories 23A1 to 23An. In addition, the moving body plane memory 23
All “0” s are written in advance in all the addresses of A1 to 23An, and only the pixels of each moving object have the same address as the difference memory 62M.
It is written in any of the moving object plane memories.

10 and 11 are flowcharts of the processing for separating the moving object plane of the microcomputer 63. That is, in the process of separating the moving object in this case, first, in step 101, non-zero pixel data is searched (since the moving pixel is not 0, the moving pixel is searched). Then, if non-zero pixel data is found in step 102, the process proceeds to step 103 to check whether the pixel data around it is non-zero. In the case of this example, as shown in FIG. 9, the data of 8 pixels a to h on the upper, lower, left, and right sides of the pixel of interest x is checked.

Then, in the next step 104, 8
If none of the data of the pixels a to h is non-zero, the pixel of interest x is regarded as an isolated point and the step 104 is performed.
Then, the procedure returns to step 101 to search for the next motion pixel.

In step 104, if any one of the eight pixels a to h is a non-zero pixel, the process proceeds from step 104 to step 105, and the pixel d to the left of the target pixel x and above (one line before). It is checked whether or not the pixel and b are non-zero pixels, and the process proceeds to the next step 106.

In the next step 106, it is determined whether the left and upper pixels d and b are both non-zero,
If both are not non-zero, that is, they are not motion pixels,
In step 107, a new number is set as the memory number of the moving object plane memory (hereinafter, simply referred to as the memory number). Then, in step 108, the memory number is stored in correspondence with the address of the pixel.
After that, the routine proceeds to step 109, where it is judged whether or not the scanning of all the pixels of the difference memory 62M is finished. When all the scanning is finished, this processing routine is finished. If all the scans have not been completed, the process returns to step 101 and the search for the next motion pixel is started.

If it is determined in step 106 that at least one of the left and upper pixels d and b is a non-zero pixel, the process proceeds from step 106 to step 110, and both are non-zero. To be determined. When it is determined that both are non-zero, the process proceeds from step 110 to step 111, and the memory numbers stored in the microcomputer 63 for both pixels d and b are checked. And next step 1
In step 12, it is determined whether or not the memory numbers of both pixels d and b match.

As a result of the determination in step 112, when the memory numbers of both pixels d and b match, the process proceeds from step 112 to step 108, and the memory number is stored in correspondence with the address of the target pixel x. .

If it is determined in step 112 that the memory numbers of both pixels d and b do not match, the process proceeds from step 112 to step 113 to select the memory number of the left pixel d. And stores the memory number in association with the target pixel x,
The memory number of the left pixel d and the memory number of the upper pixel b are related, and information (called merge information) indicating that the pixel is a pixel of one moving object even if the memory numbers are different is stored.

This is because the moving object is a pixel at a skipped position in the data of a certain horizontal scanning line, but as a result of searching the pixels of the subsequent line, it is found that the moving object is connected as a pixel of the same moving object. The case is shown.

As a result of the discrimination in step 110, when neither is non-zero, this step 110
From step S115 to step 115, it is determined whether or not the left pixel d is non-zero. As a result of the determination, when the left pixel d is non-zero, the procedure proceeds to step 116, the memory number of the pixel d is checked, and then step 10
In step 8, the memory number corresponding to the address of the target pixel x is stored.

As a result of the determination in step 115, the left pixel d
Is not non-zero, that is, when it is determined that the upper pixel b is non-zero, the process proceeds to step 117, the memory number of the upper pixel b is checked, and then step 1
08, corresponding to the address of the target pixel x,
The memory number is stored.

As described above, after step 108, the routine proceeds to step 109, where it is judged whether or not the search for all the pixels of the difference memory 62M is completed,
If not, the process returns to step 101 and the above processing routine is repeated, and when the search for all pixels is completed,
This processing routine ends.

As a result of the pixel search of the difference memory 62M, the built-in memory of the microcomputer 63 stores, for each moving object, the same memory number and associated memory for the address of the pixel included in each moving object. The number is stored with the information associating both memory numbers.
The microcomputer 63 sets the memory numbers of the pixels recognized as the same moving object to the memory number No. of one moving image plane memory.
Correspond to. As a result, each moving object can be separated as separate moving image planes as follows.

That is, the microcomputer 63 uses the difference memory 6
The moving pixel data is sequentially read from 2M. The read output of the difference memory 62M is the moving picture plane memory 23.
It is input to each of A1 to 23An. Further, the microcomputer 63 sets the read pixel as described above and supplies the write pixel address (which may be the same as the read pixel address) only to the moving picture plane memory of the stored memory number No, and the moving pixel Is written in the moving picture plane memory having the memory number No.

Thus, the moving object plane memory 23A
Each of 1 to 23An has one moving object,
It is separated and stored separately.

In the above-described method of separating moving object planes, the difference memory 62M is searched for pixels horizontally and vertically similarly to television scanning, and pixels included in the same moving object are merged. When one motion pixel is detected, the surrounding pixels are sequentially searched to track non-zero pixels and merged, and the merged pixel data is sequentially written to one motion object plane memory at the same time. In this way, the moving object plane memory for one moving object may be completed.

Even if two moving objects overlap each other at a certain point of time, the moving objects can be observed separately after a predetermined time elapses. By rewriting, the moving object plane information including only the moving objects can be stored in each moving object plane memory by the above method.

[Generation of Image Frame Position Information of Background Image and Motion Change Information of Moving Object] Next, the image frame position information of the background image and the motion change of each moving object on the background plane in the signal processing circuit 22. An example of the configuration of the information generation circuit is shown in FIG.
This will be described with reference to 2.

The image frame position information and motion change information are generated from the current image information using the data of the background plane memory 23BG and the moving object plane memories 23A1-23An. The circuit of FIG. 12 operates from the time when the imaging / recording start key is operated after the above-described preparation period has elapsed. That is, in this example, the image frame position information and the motion change information are recorded in real time.

That is, the image pickup data from the A / D converter 21 is separated by the plane separation circuit of the signal processing circuit 22 into the background plane information for one screen and the plane information for each moving object. Information about one frame of the background image and each moving object is stored in the frame memory 7
1BG and 71A1 to 71An. The frame memories 71BG and 71A1 to 71An have a two-frame buffer configuration. When the background image and the information of the moving object are being written to one frame memory, the background plane from the other frame memory and The information data of the moving object plane is read out, and the data is used for generating the image frame position information and the motion change information.

That is, the background image information from the frame memory 71BG is supplied to the image frame position change detection circuit 72BG, and the image information of each moving object from the frame memories 71A1 to 71An is supplied to the motion change detection circuit 72A1.
~ 72An. Then, the background information of the maximum image frame from the background plane memory 23BG is supplied to the image frame position change detection circuit 72BG, and the moving object plane information stored in the moving object plane memories 23A1 to 23An during the preparation period moves. Change detection circuit 72A1
It is supplied to 72An.

In the image frame position change detection circuit 72BG, the background image of the maximum image frame is compared with the background image of the frame memory 71BG, and the image frame position on the background image of the maximum image frame of the background image of the frame memory 71BG is compared. Is detected, a change from the initial position is detected, and the change information is output as image frame position information and supplied to the compression encoding circuit 26.

In the motion change detection circuits 72A1 to 72An, the moving objects stored in the moving object plane memories 23A1 to 23An and the frame memories 71A1 to 71A are stored.
By pattern matching with each moving object image from An, the motion vector, that is, the direction of motion and the amount of motion for that moving object are obtained.

In this case, since the moving object is stored in the memory as a moving object plane in advance, if the shape does not change, pay attention to a specific representative point or a representative block, and the representative point or the representative block. By performing the pattern matching with respect to, the motion vector for the entire moving object can be extracted, and the matching process can be performed in a relatively short time. The same can be said when detecting the image frame position information of the background image.

When the moving object changes its direction or shape, the pattern matching causes a large error.
Therefore, in this example, together with the motion vector, the error amount is transmitted as motion change information.

In this way, the motion change detection circuits 72A1-7A7
The motion vector and the matching error information for the moving object in each moving object plane memory obtained by 2An are supplied to the compression encoding circuit 26.

The compression coding circuit 26 compresses the input data. As described above, the amount of data after compression is much smaller than that of image information, and it is possible to easily record the data on the disc in real time.

When the camera is zoomed,
The zoom ratio information is included in the change information, and the information of the background plane and the moving object plane is passed through a low-pass filter (data thinning) according to the zoom ratio for comparison with the image pickup signal. In addition, when the photographed background extends beyond the background plane memory 23BG, the difference from the background plane is recorded together with the image frame information.

The post-movement position of the moving object in each moving object plane memory can be easily detected as an address on the memory by using the detected motion vector. Therefore, it is possible to recognize a state in which the moving objects overlap with each other by making the pixel addresses of the plurality of moving objects the same. As described above, when a plurality of moving objects are overlapped with each other, the depth between the moving objects is detected depending on which pixel of the moving object appears as the pixel of the part in the current image. Then, the depth information is transmitted together with the motion information. Note that the depth information is also obtained for the background image and the moving object.

Instead of the image frame position information of the background image,
Once the position of the initial background image is set, when you move the camera from that position by tilting or panning,
A sensor means for detecting the moving direction and the distance may be provided, and the information on the moving direction and the distance detected by the sensor means may be recorded.

Further, as the motion change information about the moving object, a predicted motion vector as in the following example and the object deformation information may be transmitted. That is, in the example of FIG. 13, the frame information of each moving object extracted from the input image information from the frame memories 71A1 to 71An is supplied to the difference calculation circuits 73A1 to 73An.

In addition, the moving object plane memories 23A1-2A
The 3A moving object plane information is used as the prediction circuits 74A1 to 74A7.
4An, and is supplied to 4An, and the motion vector predictor generating circuit 75A1
Based on the predicted motion vector from ~ 75An, the frame image data of each predicted moving object after the movement is obtained from this. Then, the predicted frame image data of each moving object is converted into the difference calculation circuits 73A1 to 73A1.
73An and is supplied to the frame memories 71A1 to 71A1.
The difference from the frame information of each moving object extracted from the input image information from An is calculated.

The difference calculation circuits 73A1 to 73An output the difference of the image of the moving object to the compression encoding circuit 26 as output data. In addition, the difference calculation circuit 73A
1 to 73An obtain the difference of the motion vector from the difference of the image of the moving object and supply it to the compression encoding circuit 26 as output data and also to the predictive motion vector generating circuits 75A1 to 75An for the next frame. Generate a motion vector predictor for each moving object.

In the above example, the background image and the still image of the moving object are separated from the input image. However, when the background image and the moving object are previously separated from each other, it is possible to take a picture with the camera. In advance, each of them is individually imaged and written in the background plane memory 23BG and the moving object plane memories 23A1 to 23An,
It can be recorded on the disk 11.

At this time, as the background image of the maximum image frame,
Pan, tilt, etc. the camera to take a picture in advance and store it in the memory 23
It can be made to accumulate in BG.

Also, in the above example, the registration of the background image of the maximum image frame in the background plane memory 23BG is performed by shooting with a camera in advance, but the background of the maximum image frame is set as follows. The image may be re-recorded after shooting and recording.

That is, in the preparatory period, as shown in FIG. 14, the initial background image BGs for one screen is written in the background plane memory 23BG, for example, at the substantially central address position. Then, when the shooting angle is changed by tilting or panning the camera, the difference between the imaged background image BGp (shown by the alternate long and short dash line in FIG. 14) and the initial background image is obtained, and the difference is used as the background. The difference background image is recorded in the background plane memory 23BG while being recorded as image change information. This is repeated until the shooting of one scene is completed.

In this way, at the end of shooting one scene, the background plane memory 23BG stores the background image of the maximum range in which the camera angle is changed, that is, the background image of the maximum image frame. Therefore, this can be recorded on the disk 11 as background plane information.

Note that what is recorded in real time may be information on the moving direction and distance of the camera detected by the above-mentioned sensor means instead of the image information of the difference.

In the above embodiment, the preparation period is set before the actual image recording and recording, and the background plane and the moving object plane are separated and recorded on the disc during the preparation period. In the case of recording at the end, since the amount of motion change information is very small, recording of still image plane information to recording of motion change information is executed in real time without providing a preparation period. It is also possible. For example, if one scene is 10 seconds, the moving object plane can be recorded in 2 seconds in the above-mentioned example, so the motion change information should be stored in the buffer memory for that 2 seconds. As a result, real-time image recording can be performed without providing a preparation period.

[Description of Disc Reproducing Device for Digital Image Signal] FIG. 15 is a block diagram of an embodiment of the disc reproducing device of this example. In this example, the same parts as those of the disc recording apparatus of the example of FIG. 1 are designated by the same reference numerals, and the description thereof will be omitted.

When the disk 11 is loaded into the apparatus, the apparatus first takes in the TOC area of the disk, and the system controller 3 records the recording positions of the background plane and the moving object plane of each scene and its motion change information. Recognize position.

Then, from the TOC area information, the system controller 3 first reproduces the information of the background plane of the maximum image frame of the scene to be reproduced and the plurality of moving object planes.

These pieces of image information extracted from the disk 11 are supplied from the RF circuit 28 to the reproduction processing circuit 81, where data of a predetermined recording format such as a sector structure is decoded and the decoded data is expanded. And the plane separation circuit 82. And
In this circuit 82, each plane information compressed at a low compression rate is decompressed and separated for each plane information. The background plane information is stored in the background plane memory 83BG, and the animal body plane information is stored in the animal plane information. It is written in the body plane memories 83A1 to 83An, respectively. This completes the preparation for starting moving image reproduction.

Next, the image frame position information, motion change information, depth information, rotation information, etc. of the background image of the scene are extracted from the disc in real time by referring to the TOC area information, and the RF circuit 28 and the reproduction processing are performed. The data is supplied to the data expansion / decoding circuit 84 via the circuit 81. Then, the motion change information and the like are decompressed and decoded, and the signal processing circuit 85.
Is supplied to.

In addition, the signal processing circuit 85 includes a background plane memory 83BG and a moving object plane memory 83A1.
Each still image information from 83An is also supplied. In the signal processing circuit 85, the background plane memory 8
The background image based on the image frame position information is read from the 3BG, and the moving object plane memories 83A1 to 83A1 to 8A are added to the background image.
The image of each moving object from 3An is decompressed and decoded by the decompression / decoding circuit 84.
Are combined using the motion change information and the depth information for each moving object from.

That is, such a composition that a moving object is pasted on a frame or field basis at a position according to motion change information and an overlap according to depth information (also overlapping with a background image) on a background image The original moving image is obtained.

At this time, the image frame position for the background image is
By operating the image frame position changing key of the key group 4, it is possible to change the recorded image frame position information in the vertical and horizontal directions. That is, when the image frame position change key is operated, the image frame position is changed in the direction specified by the change key with respect to the image frame position determined by the reproduced image frame position information, and the changed image is displayed. The background image at the frame position is read from the background plane 83BG. That is, the image frame position change key can change the image frame position of the background image during reproduction to any position within the range of the background plane.

A reproduction zoom key is provided, and when the reproduction zoom key is operated, the background image of the image frame enlarged or reduced according to the zoom ratio is read from the memory 83BG.
At this time, the data is interpolated or thinned according to the zoom ratio so as to fit the data of one screen of 720 pixels × 480 lines. In this way, the user can enjoy making a desired picture on the reproducing side regardless of the image frame position at the time of image capturing.

The moving image data from the signal processing circuit 85 is returned to the original analog signal by the D / A converter 86, is derived from the output terminal 87, and the reproduced image is reproduced on the image monitor device connected to this output terminal. Is projected.

The information of the background plane and the moving object plane for each scene is first read from the disc, and then the motion change information is sequentially read from the disc, whereby the moving image of each scene can be reproduced. In this case,
Since the amount of motion change information for each scene is very small,
Rather than extracting motion change information for one scene from the disc in real time of a moving image, a buffer memory is provided, and motion change information is extracted after each plane information and stored in the buffer memory, and sequentially from that buffer memory. It is also possible to perform a process of reading out the motion change information according to the moving image.

In such a case, since the moving image reproduction processing and the extraction of the reproduction signal from the disc can be separated, the plane information of the next scene is recorded on the disc during the reproduction of the previous scene. Can be extracted from and stored in another plane memory. By doing so, it is possible to continuously reproduce a plurality of scenes without interruption.

As described above, according to the present invention, the image is divided into the background image and the moving object plane, which are transmitted with high image quality, and the moving changes of the moving object plane are also transmitted and combined at the time of reproduction. As a result, even in the case of a transmission medium having a low transmission rate, it is possible to transmit a moving image with high image quality and smooth motion.

For example, conventionally, a so-called MPEG compression method of image data is known. In this method, the image information of one frame (still image) is sent first, and then the first. This is a method of taking the difference from the image frame of No. 1, and compressing the residual data for transmission. The number of bits of the image data of the first one frame in this MPEG is, for example, 400 K bits when the data is compressed. This 400 K-bit image has a relatively high image quality.

Since this 400 K-bit image is one frame of information, if this is expressed in bps, one second is:
Since it consists of 30 frames, it corresponds to 12 Mbps.
Therefore, a fairly high quality image is obtained. MP
In EG, since only the residual information is sent as the subsequent information, the reproduced image is deteriorated, but the image of the first one frame itself has a good image quality.

On the other hand, according to the above-described configuration of the present invention, the information of the plurality of image planes of the background plane and the moving object plane is transmitted as image data equivalent to 12 Mbps equivalent to MPEG, and a few bits are transmitted. The moving image plane is moved based on the motion change information transmitted as a number and is combined with the background plane to reproduce the moving image, so the image quality is good and the motion vector Since the information is real-time information, the movement is not jerky and is good.

In the above example, assuming that only the background plane is changed by panning, tilting, and zooming, only the background image is transmitted over a wider range than the image frame for one screen. Similarly, with respect to the moving object plane, it is also possible to prepare and transmit an image in a range wider than the image frame for one screen.

It should be noted that the motion information separated from the background plane is not transmitted separately to the moving object plane composed of still images of a plurality of moving objects as in the above example, but is transmitted to these moving objects. The present invention can also be applied to an apparatus that compresses motion information including the data and transmits the data separately from the background plane.

In the above example, the magneto-optical disk is used as the image data transmission medium, but the image data is transmitted via a tape or another recording medium, and further, a cable or a transmission path using radio waves. Needless to say, the present invention is applicable.

[0141]

As described above, according to the present invention, in the transmission apparatus in which the image is divided into the still image information (background plane) of the background and the motion information and transmitted, the background plane is Since the still image information in a wider range than the image frame reproduced as one screen is transmitted, at the receiving side, when the receiving side takes this background plane into the memory and reads it from this memory, the image frame to be read out. By specifying the position, a desired background image can be extracted from a wide range of background planes to obtain a reproduced image. It is also possible to display the background of an image frame of arbitrary size that has been zoomed.

Further, according to the present invention, the image is divided into a still image of the background plane and a still image of the moving object of the moving object plane, and the information of the plurality of still image planes is not compressed or high image quality is maintained. In addition to transmitting at low compression rate at low speed, motion change information is transmitted at high speed with a small number of bits, and the playback side moves the plane of the moving image object with good image quality based on the motion change information, Since a moving image is reproduced by synthesizing with a plane, it is possible to obtain a reproduced image with good image quality and good motion without jerky motion.

[Brief description of drawings]

FIG. 1 is a block diagram of a disk recording apparatus as an embodiment of a digital image signal transmission apparatus according to the present invention.

FIG. 2 is a diagram for explaining an essential part of the present invention.

FIG. 3 is a diagram for explaining a signal recording timing in the example of FIG.

FIG. 4 is a diagram for explaining the example of FIG. 1.

FIG. 5 is a diagram for explaining an example of a background plane memory 23BG used in an embodiment of the present invention.

FIG. 6 is a diagram showing an example of a background image.

FIG. 7 is a block diagram of an embodiment of a main part of a digital image signal transmission device according to the present invention.

8 is a diagram for explaining the operation of the example in FIG. 7. FIG.

9 is a diagram for explaining the operation of the example in FIG. 7. FIG.

10 is a diagram showing a part of a flowchart of the operation of the example of FIG. 7. FIG.

11 is a diagram showing a part of a flowchart of the operation of the example of FIG.

FIG. 12 is a block diagram of an embodiment of a main part of a digital image signal transmission device according to the present invention.

FIG. 13 is a block diagram of another embodiment of the main part of the digital image signal transmission device according to the present invention.

FIG. 14 is a diagram for explaining another example of the embodiment of the present invention.

FIG. 15 is a block diagram of an embodiment of a digital image signal receiving apparatus according to the present invention.

[Explanation of Codes] 22 Signal Processing Device 23BG Background Plane Memory 23A1-23An Animal Body Plane Memory 24 Compression Circuit 26 Compression Encoding Circuit 31 Background Plane 32-34 Animal Body Plane Memory 62 Animal Body Plane Separation Circuit 62M Difference Memory 72BG Picture Frame Position change detection circuit

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical indication H04N 7/13 Z

Claims (6)

[Claims] 1. A transmission device of a digital image signal for transmitting a screen by dividing it into still image information of a background image and information of a moving object moving on the background image, wherein the background image information of the still image is used. A digital image signal transmission device in which background information in a wider range than an image frame reproduced as one screen is transmitted. 2. The digital image signal transmission device according to claim 1, wherein the background plane memory means stores still image information of a background image in a range wider than an image frame reproduced as the one screen, and the background image. Means for separating the information of the moving object moving above into still images of the respective moving objects, moving object plane memory means for individually storing the still image information of the respective moving objects, an input digital image signal and the above Change information detecting means for detecting change information for the still image stored as the moving object plane information based on the output of the memory means, encoding means for compressing and encoding the output of the change information detecting means, and the memory Means for transmitting the digital image signal, which comprises still image information of the plurality of pieces of plane information of the means, and transmission means for transmitting the change information from the encoding means. Sending device. 3. Still image information of a plurality of plane information of the memory means is transmitted without compression or at a low compression rate, and change information from the encoding means is compressed and transmitted. The digital image signal transmission device according to claim 1, wherein the transmission device is a digital image signal transmission device. 4. The digital image signal is obtained by A / D converting an image pickup output of a video camera, and the transmission means is recording on a recording medium, and the background plane information is used in actual photographing. A background, which is planned to be used as a background and is wider than the image frame reproduced as one screen, is recorded in advance, and the change information about the moving object plane includes the position on the background plane. 2. The digital image signal transmission device according to claim 1, further comprising information for determining. 5. The digital image signal is obtained by A / D converting an image pickup output of a video camera, the transmitting means is recording on a recording medium, and the image frame position of the photographing by the video camera. When the operation of changing the image plane is performed, the image portion protruding from the initial background plane for one screen is sequentially written in addition to the initial background image of the background plane memory means, and the contents of the background plane memory means are recorded in the recording medium. The digital image signal transmitting apparatus according to claim 1, wherein 6. A digital image signal receiving device transmitted by the digital image signal transmitting device according to claim 1, wherein each of the still image information of the background plane information and the moving object plane information is stored. Memory means, decoding means for decoding the compression-encoded change information, means for designating a background image portion to be read as one screen of the background plane information, and one for the one screen. For the background image, combine the moving object plane information based on the change information,
A digital image signal receiving apparatus comprising: a synthesizing unit for obtaining an output digital image signal.