JP2008282135A - Image processing apparatus, image reading apparatus, image forming apparatus, and image processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce cost by simplifying a structure for performing rotation processing of image data. <P>SOLUTION: An image processing apparatus includes: a work memory 53; first and second rotation processing units 51 and 52 which rotate image data by using the same work memory 53 and by changing a reading order of image data from the work memory 53 for a writing order of image data to the work memory 53, and performs the rotation processing by dividing image data into a plurality of blocks; and a time division use control unit for allowing the first rotation processing unit 51 and the second rotation processing unit 52 to time-divisionally use the work memory 53 for the rotation processing. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image processing apparatus, an image reading apparatus, an image forming apparatus, and an image processing method that rotate and output input image data.

  Conventionally, an image forming apparatus such as a digital copying machine has a plurality of functions such as a scanner function and a printer function. In this type of image forming apparatus, predetermined or designated image processing is performed on image data obtained by reading a document image with a scanner unit, and the processed image data is stored in a storage unit. Further, the image data stored in the storage unit is read from the storage unit in response to an output instruction, printed by the printer unit, and output.

  As described above, when the image data obtained by reading the original image is stored in the storage unit, and when the image data stored in the storage unit is output as a print image, normal image data rotation processing is performed. Is done. For example, Patent Document 1 discloses that when image data is rotated in a multi-function image input / output device, processing by hardware and processing by software are selectively used in band units of a predetermined size according to job priority. It is described.

  FIG. 17 is an explanatory diagram showing an outline of a rotation process when image data is rotated by 90 degrees. The rotation process in the digital copying machine is a process in which image data stored in a large-capacity memory is read in units of small blocks, rotated in units of blocks, and then stored in the large-capacity memory again. In this rotation process, first, a first area for storing image data to be subjected to the rotation process and a second area for storing image data after the rotation process are secured in the large-capacity memory. Next, image data to be rotated is read from the first area into a small-capacity memory inside the data rotation unit in units of blocks. After the data rotation unit rotates the image data in units of the blocks, Write to the second area. By repeating the rotation processing in units of small blocks as described above, the rotation processing of the entire image data is completed.

  FIG. 18 is a block diagram showing a schematic configuration of a conventional digital copying machine that performs image data rotation processing. The digital copying machine includes a scanner unit 101, a printer unit 102, a large capacity memory 103, a control unit 104, and an image processing unit 105. The image processing unit 105 performs rotation processing on the image data read from the large-capacity memory 103 by the first data rotation unit 112 and the second data rotation unit 115, and performs predetermined image processing before and after these rotation processing. The processed image data is stored in the large-capacity memory 103.

  In order to perform the above processing, the image processing unit 105 includes a first preprocessing unit 111, a first data rotation unit 112, a first post processing unit 113, a second preprocessing unit 114, a second data rotation unit 115, and a first data rotation unit 115. 2 post-processing unit 116 is provided. For example, the first preprocessing unit 111 performs a predetermined filter process on the image data input from the scanner unit 101. The first data rotation unit 112 performs rotation processing on the image data after the filter processing. The first post-processing unit 113 performs JPEG compression on the image data after the rotation processing. The second preprocessing unit 114 decompresses JPEG-compressed image data for print processing. The second data rotation unit 115 rotates the JPEG decompressed image data so as to match the set printing direction on the paper. The second post-processing unit 116 performs processing such as color conversion on the image data after the rotation processing so as to be suitable as image data processed by the printer unit 102.

  FIG. 19 is a block diagram showing in detail the configuration of the image processing unit 105 shown in FIG. As shown in FIG. 18, the image processing unit 105 includes data when each processing unit shown in FIG. 18 reads image data from the large-capacity memory 103 and writes processed image data to the large-capacity memory 103. A bus arbitration unit 117 is provided as arbitration means. The first data rotation unit 112 and the second data rotation unit 115 include work memories 112a and 115a, which are buffers as small-capacity memories, respectively.

FIG. 20 is a block diagram illustrating in detail the configuration of the first data rotation unit 112 and the second data rotation unit 115 illustrated in FIG. As shown in the figure, the first and second data rotation units 112 and 115 include a DMA (Direct Memory Access) read control unit 121, a DMA write control unit 122, a DMA read address calculation unit 123, and a DMA write address calculation unit 124. , An SRAM write control unit 125, an SRAM read control unit 126, a buffer selection control unit 127, an sRAM write selection unit 128, an sRAM read selection unit 129, the work memories 112a and 115a, a register 130, and an interrupt control unit 131. In addition, a read DMA arbitration unit 132 is connected to the DMA read control unit 121, and a write DMA arbitration unit 133 is connected to the DMA write control unit 122.
JP 2006-173843 A (released August 29, 2006)

  In the configuration shown in FIG. 18, when the digital copying machine receives a print command from the printer unit 102 while performing a process based on an image reading command by the scanner unit 101, the digital copying machine simultaneously performs a printing process based on the command. That is, it is required to support multi-access.

  On the other hand, for example, when the image data obtained by the reading operation of the scanner unit 101 is processed by the first preprocessing unit 111, the first data rotation unit 112, and the first postprocessing unit 113 of the image processing unit 105, normally, The processing speed of the rotation processing in the first data rotation unit 112 is faster than the processing in the first preprocessing unit 111 and the first postprocessing unit 113. For this reason, the first data rotation unit 112 is often in a standby state while the first pre-processing unit 111 or the first post-processing unit 113 is performing processing.

  However, in the above-described conventional configuration, the first data rotation unit 112 can perform rotation processing on image data of other documents unless the processing of the first preprocessing unit 111 and the first postprocessing unit 113 is completed. Can not. Accordingly, in order to cope with multi-access, as shown in FIG. 18, in addition to the first data rotation unit 112, the second data rotation unit 115 is necessary, and such a configuration causes an increase in cost. ing.

  Accordingly, an object of the present invention is to provide an image processing apparatus, an image reading apparatus, an image forming apparatus, and an image processing method capable of reducing the cost by simplifying the configuration for performing rotation processing of image data.

  The image processing apparatus of the present invention uses the same rotation image memory as the rotation image memory, and stores the image data from the rotation image memory in the order of writing the image data to the rotation image memory. The image data is rotated by changing the reading order, and the rotation processing is performed by dividing the image data into a plurality of blocks, and the rotation image in the rotation processing. It is characterized by comprising a time-division use control unit that causes the memory to be used in a time-sharing manner by the first rotation processing unit and the second rotation processing unit.

  The image processing method of the present invention uses the same image memory for rotation, and changes the reading order of image data from the image memory for rotation with respect to the order of writing image data to the image memory for rotation. The image data is rotated, and the rotation process is performed by dividing the image data into a plurality of blocks, and the rotation image memory is stored in the rotation process. The first rotation processing step and the second rotation processing step are used in a time-sharing manner.

  According to the above configuration, in the rotation processing by the first and second rotation processing units (first and second rotation processing steps), the same image memory for rotation is used in a time-sharing manner by both of them. Accordingly, in a configuration using the same image memory for rotation, image processing involving rotation processing by the first rotation processing unit (first rotation processing step) and second rotation processing unit (second rotation processing step) The image processing accompanied by the rotation processing by the can be performed in parallel. Thereby, in the image processing apparatus (image processing method), it is possible to reduce the circuit scale and cost by reducing the rotation image memory while maintaining a desired processing speed.

  In the image processing apparatus, the time-division use control unit includes a data amount of first image data that is rotated by the first rotation processing unit and a second image that is rotated by the second rotation processing unit. A ratio of time-division use of the image memory for rotation between the first rotation processing unit and the second rotation processing unit may be set according to the data amount of data.

  According to the above configuration, according to the data amount of the first image data rotated by the first rotation processing unit and the data amount of the second image data rotated by the second rotation processing unit, The ratio of time-division use of the image memory for rotation of the first rotation processing unit and the second rotation processing unit is set. For example, when the image data format to be processed is different between the first rotation processing unit and the second rotation processing unit, the first rotation processing unit and the second rotation processing unit depend on the format of the image data. The ratio of the usage time of the image memory for rotation is set. Therefore, when the data amount of the first image data is different from the data amount of the second image data, the process of either the first rotation processing unit or the second rotation processing unit is completed significantly earlier. However, there is no processing time imbalance such that the other ends significantly later.

  As a result, when image processing with rotation processing by the first rotation processing unit and image processing with rotation processing by the second rotation processing unit are performed in parallel, for various image data having different data amounts Thus, processing conforming to the specification of the processing time ratio between the image data becomes possible.

  In the above-described image processing apparatus, when one of the first image data and the second image data is color image data and the other is monochrome image data, the time-division use control unit Rotation processing monochrome image data with the time-division use ratio of the image memory for rotation by the rotation processing section that processes color image data out of the first rotation processing section and the second rotation processing section It is good also as a structure made larger than the ratio of the time division use of the said image memory for rotation by a process part.

  According to the above configuration, it is possible to avoid a situation in which the time required for the rotation processing by the rotation processing unit that processes the color image data among the first rotation processing unit and the second rotation processing unit is significantly increased. be able to. That is, there is no imbalance between the rotation processing time of the rotation processing unit that processes color image data and the rotation processing time of the rotation processing unit that processes monochrome image data.

  Thereby, in the image processing apparatus, when the image processing accompanied by the rotation processing by the first rotation processing unit and the image processing accompanied by the rotation processing by the second rotation processing unit are performed in parallel, Processing conforming to the specification of the processing time ratio with monochrome image data can be performed.

  In the above image processing apparatus, when the first image data and the second image data are color image data having the same data amount or monochrome image data having the same data amount, the time division use control unit May be configured such that the ratio of time-division use of the image memory for rotation by the first rotation processing unit and the second rotation processing unit is equalized.

  In the image processing apparatus, one of the first image data and the second image data is color image data in RGB signal format, and the other is color image data in CMYK signal format. It is good.

  The image processing apparatus is capable of transmitting / receiving data to / from a document image reading unit that reads an image of a document and obtains image data, and includes an image data storage memory, and the first rotation processing unit includes the document The image data input from the image reading means is rotated, and the image data after the rotation processing is stored in the image data storage memory, while the second rotation processing unit is read from the image data storage memory The image data may be rotated and then stored in the image data storage memory.

  The image processing apparatus is capable of transmitting / receiving data to / from a printing unit that performs printing based on image data, and the second rotation processing unit performs the rotation process according to a printing operation of the printing unit. It is good.

  According to the above configuration, the first rotation processing unit rotates the image data input from the document image reading unit, and the second rotation processing unit performs the printing operation according to the printing operation of the printing unit. Therefore, the image data read from the image data storage memory is rotated. Therefore, the rotation processing of each image data can be appropriately performed corresponding to the document image reading unit and the printing unit.

  The image reading apparatus of the present invention comprises the document image reading means and the image processing apparatus.

  According to the above configuration, the image reading apparatus can be configured as an apparatus such as a scanner including a document image reading unit and an image processing apparatus having a function of rotating image data.

  The image forming apparatus of the present invention includes the original image reading unit, the image processing device, and a printing unit that performs printing based on image data, and the second rotation processing unit is configured to perform a printing operation of the printing unit. The rotation process is performed.

  According to the above configuration, the image forming apparatus includes the document image reading unit, the image processing device, and the printing unit that performs printing based on the image data. The image processing device includes the document image reading unit and the printing unit. Correspondingly, it can be configured as a device such as a digital copying machine that performs rotation processing of each image data.

  According to the configuration of the present invention, in the configuration using the same rotation image memory, the image processing with the first rotation processing and the image processing with the second rotation processing can be performed in parallel. As a result, the circuit scale can be reduced and the cost can be reduced by reducing the rotation image memory while maintaining a desired processing speed.

  An embodiment of the present invention will be described below with reference to the drawings. A digital copying machine as an image forming apparatus according to the present embodiment has the configuration shown in FIG. FIG. 1 is a block diagram showing a schematic configuration of a digital copying machine having a function of rotating image data.

  As shown in FIG. 1, a digital copying machine includes a scanner unit (original image reading unit) 1, a printer unit (printing unit) 2, a large-capacity memory (image data storage memory) 3, a control unit (time division use control unit). ) 4 and an image processing unit 5. The scanner unit 1 reads an image of a document and converts it into image data. The printer unit 2 prints a visualized image of the image data on a sheet based on the image data. The large capacity memory 3 is composed of, for example, a DDR (Double Data Rate) SDRAM. This digital copying machine can cope with multi-access between an image reading request using the scanner unit 1 and a printing request using the printer unit 2. That is, the image reading operation by the scanner unit 1 and the printing operation by the printer unit 2 can be performed in parallel.

  The image processing unit 5 performs rotation processing on the image data read from the large-capacity memory 3 by the data rotation unit 11, performs predetermined image processing before and after these rotation processing, and increases the processed image data. Store in the capacity memory 3. In order to perform these processes, the image processing unit 5 includes a data rotation unit 11, a first preprocessing unit 12, a first postprocessing unit 13, a second preprocessing unit 14, and a second postprocessing unit 15.

  The data rotation unit 11 performs a rotation process (first rotation process) on the image data processed by the first preprocessing unit 12 and a rotation process (second rotation) on the image data processed by the second preprocessing unit 14. Rotation process). These rotation processes are appropriately performed according to the setting or according to a command based on, for example, a user input.

  The first rotation process is a process for matching the image data read by the scanner unit 1 with the display direction on the screen of a personal computer, for example. The second rotation process is a process for matching the printing direction on the paper when the image data stored in the large-capacity memory 3 is printed on the paper by the printer unit 2.

  The first preprocessing unit 12 performs, for example, a predetermined filter process on the image data input from the scanner unit 1. The first post-processing unit 13 performs, for example, JPEG compression on the image data. For example, the second preprocessing unit 14 decompresses JPEG-compressed image data for print processing. The second post-processing unit 15 performs processing such as color conversion so as to be suitable as image data processed by the printer unit 102.

  FIG. 2 is a block diagram showing in detail the configuration of the image processing unit 5 shown in FIG. As shown in the figure, the image processing unit 5 is data when each processing unit shown in FIG. 1 reads out image data from the large-capacity memory 3 or writes processed image data into the large-capacity memory 3. A bus arbitration unit (time division use control unit) 16 is provided as arbitration means. The data rotation unit 11 includes a first rotation processing unit 51, a second rotation processing unit 52, and a work memory (rotation image memory) 53. The work memory 53 is a small capacity memory (buffer) and serves as a work area when the first and second rotation processing units 16 and 17 perform the first and second rotation processes. The first and second rotation processing units 16 and 17 share one work memory 53 and respectively perform rotation processing of image data.

  FIG. 3 is a block diagram showing in detail the configuration of the data rotation unit 11 shown in FIG. As shown in the figure, the data rotation unit 11 includes a DMA read control / arbitration unit 21, a DMA write control / arbitration unit 22, a first DMA read address calculation unit 23, a second DMA read address calculation unit 24, and a first DMA write address calculation. Unit 25, second DMA write address calculation unit 26, first SRAM write control unit 27, second SRAM write control unit 28, first SRAM read control unit 29, second SRAM read control unit 30, first buffer selection control unit 31, second buffer A selection control unit 32, an sRAM write selection unit 33, an sRAM read selection unit 34, the work memory 53, a register 35, and an interrupt control unit 36 are provided. A read DMA arbitration unit 37 is connected to the DMA read control / arbitration unit 21, and a write DMA arbitration unit 38 is connected to the DMA write control / arbitration unit 22. The read DMA arbitration unit 37 and the write DMA arbitration unit 38 correspond to the bus arbitration unit 16 shown in FIG.

  The DMA read control / arbitration unit 21 transmits a read request for image data stored in the large-capacity memory 3 to the read DMA arbitration unit 37 (command transmission operation). In this case, the DMA read control / arbiter 21 obtains the address of the area to be read from the large-capacity memory 3 from the first DMA read address calculator 23 or the second DMA read address calculator 24 and makes the read request. When one read operation is completed, the first or second DMA read address calculation unit 23, 24 is notified of the end of the read operation, and the address of the area to be read next is calculated by the first or second DMA read address calculation. Obtained from the units 23 and 24.

  The DMA read control / arbitration unit 21 obtains the transmission timing of the read request to the read DMA arbitration unit 37 from the register 35 when the image data read from the large capacity memory 3 is rotated and stored in the large capacity memory 3. When the input image data is rotated and stored in the large-capacity memory 3, and when the image data stored in the large-capacity memory 3 is rotated and output, it is acquired from each module. When the command transmission delay is set in the register 35, a waiting time corresponding to the delay is provided after the command transmission request is generated, and after the waiting time has elapsed, the command (reading the above-mentioned reading) is performed to the reading DMA arbitration unit 37. Request).

  The above modules are the first preprocessing unit 12, the first postprocessing unit 13, the second preprocessing unit 14 and the second postprocessing unit 15 shown in FIG. By obtaining the end notification of each module, the read request is sent to the read DMA arbitration unit 37.

  The DMA write control / arbitration unit 22 transmits a request to write image data to the large-capacity memory to the write DMA arbitration unit 38 (command transmission operation). In this case, the DMA write control / arbitration unit 22 acquires the address of the area to be written in the large capacity memory 3 from the first DMA write address calculation unit 25 or the second DMA write address calculation unit 26, and makes the write request. When one write operation is completed, the end of the write operation is notified to the first or second DMA write address calculators 25 and 26, and the address of the area to be written next is calculated by the first or second DMA write address. Acquired from the units 25 and 26.

  The DMA write control / arbitration unit 22 acquires the timing of the write request to the write DMA arbitration unit 38 from the first SRAM read control unit 29 or the second SRAM read control unit 30. When the command transmission delay is set in the register 35, a waiting time corresponding to the delay is provided after the command transmission request is generated, and after the waiting time has elapsed, a command (the writing described above) is sent to the write DMA arbitration unit 38. Request).

  The first and second DMA read address calculation units 23 and 24 obtain from the register 35 information on the position where the image data to be rotated in the large-capacity memory 3 is stored (pre-rotation stored position information). The area to be read sequentially in 3 is calculated. The calculation result is transmitted to the DMA read control / arbiter 21.

  The first and second SRAM write control units 27 and 28 select which block to use from the blocks (sRAM) set by dividing the work memory 53 into a plurality of areas according to each mode and timing, The selection result is transmitted to the sRAM write selection unit 33 as used block information. The designation and control of the write address of the work memory 53 are performed by the first and second SRAM write control units 27 and 28.

  The first and second DMA write address calculators 25 and 26 obtain information on the position where image data should be stored in the large-capacity memory 3 (post-rotation storage position information) from the register 35, and write the image data sequentially. Calculate The calculation result is transmitted to the DMA write control / arbitration unit 22.

  The first SRAM read control unit 29 and the second SRAM read control unit 30 select which block to use among the blocks (sRAM) set by dividing the work memory 53 into a plurality of areas according to each mode and timing. Then, the selection result is transmitted to the sRAM read selection unit 34 as used block information. The first and second SRAM read control units 29 and 30 specify and control the read address of the work memory 53.

  The first buffer selection control unit 31 designates the block of the work memory 53 controlled by the first SRAM write control unit 27 and the first SRAM read control unit 29. Also, the write start timing and read start timing for each block are determined. Similarly, the second buffer selection control unit 32 designates the block of the work memory 53 controlled by the second SRAM write control unit 28 and the second SRAM read control unit 30. Also, the write start timing and read start timing for each block are determined.

  The sRAM write selection unit 33 sets a data bus according to the used block information and the used input buffer signal from the first or second SRAM write control units 27 and 28.

  The sRAM read selection unit 34 sets the data bus according to the used block information and the used input buffer signal from the first or second SRAM read control units 29 and 30.

  In the register 35, setting information for various operations is written by a CPU (not shown).

  When an interrupt process occurs, the interrupt control unit 36 performs control for the interrupt process. In response to a request from the DMA read control / arbitration unit 21, the read DMA arbitration unit 37 can appropriately perform this operation when the DMA read control / arbitration unit 21 reads data from the work memory 53. Arrange bus lines. In response to a request from the DMA write control / arbitration unit 22, the write DMA arbitration unit 38 can appropriately perform this operation when the DMA write control / arbitration unit 22 writes data to the work memory 53. Arrange bus lines.

  Here, the work memory 53 will be described in more detail. In FIG. 3, the work memory 53 is divided into four blocks (areas) as an example. Hereinafter, these blocks (areas) are referred to as rotation memory blocks. Each memory block for rotation has 2048 words × 32 bits, that is, an address 2048 and a bit width 32. The memory capacity (size) of each rotation memory block is determined by how much capacity one rotation memory block is to be made, and is not particularly limited.

  The number of memory blocks for rotation is not particularly limited, and is set according to the data reading speed from the work memory 53, for example. In the example of FIG. 3, since the work memory 53 has four rotation memory blocks, when 90-degree rotation data is read, four pixels can be read per clock. In this configuration, the reading speed is four times as compared with the case of one rotation memory block.

  As described above, in the configuration in which the work memory 53 includes a plurality of rotation memory blocks, processing is continuously assigned to each rotation memory block based on the processing speed and data capacity required for the digital copying machine. As a result, the work memory 53 has fewer standby states, and efficient rotation processing using the work memory 53 becomes possible.

  In the digital copying machine according to the present embodiment, the work memory 53 has two or more rotation memory blocks, and the rotation memory blocks are shared in a time-sharing manner. Therefore, the configuration for rotating the image data can be realized with a small circuit scale, and the rotation processing performance required according to the type of the image data can be realized.

  In the above configuration, the rotation processing of image data in the digital copying machine will be described. FIG. 4 is an explanatory diagram showing an outline of image data rotation processing in the data rotation unit 11 shown in FIG. In the rotation processing of FIG. 4, the image data is rotated 90 degrees rightward, and the image data on the large-capacity memory 3 is in a state where the size in the main scanning direction and the size in the sub-scanning direction are switched. This rotation process is the same as the conventional one.

  In the above rotation processing, image data for one page is divided into a plurality of blocks, and the rotation processing is performed in units of these blocks. By performing this process for the number of blocks, the rotation process for one page is completed. Hereinafter, the block of image data is referred to as a data block. The arrows in the diagram on the left side of FIG. 4 indicate the reading order of each data block when reading the image data of one data block (one circled number area) from the large capacity memory 3. Also, the arrows in the large-capacity memory 3 in the diagram on the right side of FIG. 4 indicate the writing order of each data block when writing one data block to the large-capacity memory 3.

  FIG. 5 is an explanatory diagram showing the rotation process shown in FIG. 4 in detail including the process on the work memory 53. Here, 128 pixels × 64 lines are defined as one data block, and the image data for one data block is read from the large-capacity memory 3 and written to the work memory 53 of the data rotation unit 11, and then read from the work memory 53 to be large Writing to the capacity memory 3. As shown in FIG. 5, the data rotation unit 11 reads the image data from the large-capacity memory 3 and writes the data to the work memory 53, and the reading order from the work memory 53 and writes it to the large-capacity memory. The rotation processing is performed by changing the reading order from the work memory 53 in this case. Specifically, in the case of writing to the work memory 53, the right end region at the upper end of the work memory 53 is written in the right direction, and in the case of reading from the work memory 53, the lower end of the left end of the work memory 53 is written. Reading is performed upward starting from the area.

  FIG. 6A is an explanatory diagram showing a write process to the work memory 53 and a read process from the work memory 53 when the work memory 53 is used without being divided. FIG. 6B is an explanatory diagram showing a writing process to the work memory 53 and a reading process from the work memory 53 when the work memory 53 is divided and used. FIG. 6B corresponds to the processing in the data rotation unit 11 of the present embodiment shown in FIG. The work memory 53 is divided into four blocks (rotation memory blocks) of 128 pixels × 64 lines corresponding to the data amount (128 pixels × 64 lines) for one data block.

  When the work memory 53 is used without being divided (FIG. 6A), the writing process to the work memory 53 and the reading process from the work memory 53 are the same as the processes for the work memory 53 shown in FIG. . For example, when the work memory 53 is divided into four parts (FIG. 6 (b)), the writing process to the four rotation memory blocks is performed sequentially, so the processing speed is the same as in FIG. 6 (a). is there. On the other hand, in the case of the reading process from the work memory 53, the image data can be read simultaneously from the four rotation memory blocks, that is, the image data of 4 pixels can be read simultaneously, so that the processing speed is increased.

  FIG. 7A is an explanatory diagram showing the writing process to the work memory 53 when the image data to be processed is RGB (24 bit) data, and FIG. 7B is the image data to be processed being K (4 bit) data. FIG. 7C is an explanatory diagram showing the writing process to the work memory 53 when the image data to be processed is K (1 bit) data.

  In FIG. 7A to FIG. 7C, the four rotation memory blocks included in the work memory 53 are represented as FIFO_0 to FIFO_3. For example, when RGB image data is rotated by 90 degrees, FIFO_0 to FIFO_3 store data of different lines from the large-capacity memory 3, respectively. Image data of the (n × 4-3) (n = 0, 1,...) Line on the large-capacity memory 3 is written into the FIFO of the Nth line. When reading out the image data from the work memory 53, a total of four pixels are simultaneously read out from the four FIFOs one by one. Therefore, for example, only the first pixel data is read from 64 lines by 16 reading operations.

  In the image data writing process to the work memory 53, when the image data to be processed is RGB (24 bit) data, as shown in FIG. 7A, the first to 128th pixels in the Nth line are FIFO_0. Read in. Note that N = n × 4-3 (n is an integer)). The first pixel to the 128th pixel on the (N + 1) th line are read into FIFO_1. The first pixel through the 128th pixel on the N + 3 line are read into FIFO_2. The first pixel through the 128th pixel on the N + 4th line are read into FIFO_3.

  If the image data to be processed is K (4 bit) data, the first to 256th pixels on the Nth line are read into FIFO_0 as shown in FIG. 7B. The first pixel to the 256th pixel on the (N + 1) th line are read into FIFO_1. The first pixel to the 256th pixel on the N + 3 line are read into FIFO_2. The first pixel to the 256th pixel on the N + 4th line are read into FIFO_3.

  If the image data to be processed is K (1 bit) data, the first to 512th pixels on the N-th line are read into FIFO_0 as shown in FIG. 7C. The first pixel to the 512th pixel on the (N + 1) th line are read into FIFO_1. The first to 512th pixels on the N + 3 line are read into FIFO_2. The first to 512th pixels on the N + 4th line are read into FIFO_3.

  As described above, in the present embodiment, the work memory 53 is configured to have four rotation memory blocks (2048 words × 32 bits) of a certain size. Therefore, by changing the number of pixels stored in the work memory 53 according to the format of the image data to be processed, the work memory 53 can be used without waste.

  FIG. 8 shows the number of pixels for each image format that can be stored in the work memory 53 when the work memory 53 has a configuration of 2048 words × 32 bits × 4. This number of pixels corresponds to the size of each data block when image data is divided into a plurality of data blocks and rotated. In FIG. 8, the Ch unit described in the remarks column when the image format is CMYK (8 bits / ch) means that one plane (C-C-C-, M -M-M-). In contrast, RGB is a sequence of RGB-RGB for each pixel.

  FIG. 9 shows the data size (data amount) for each image format in A4 size 600 dpi.

  In the above-described configuration, in the image forming apparatus according to the present embodiment, the first rotation processing unit 51 and the second rotation processing unit 52 of the data rotation unit 11 share the work memory 53 by time division use. In this case, the right to use the work memory 53 of the first rotation processing unit 51 and the second rotation processing unit 52 is not equally allocated, but the amount of image data (image format) to be processed and the digital copying machine ( And the processing speed for each image format required for the image forming apparatus). If attention is paid only to the data amount, the work memory 53 is set to be usable for a relatively long time as the amount of data to be processed increases. Thereby, the standby time of the work memory 53 is shortened, the work memory 53 can be used efficiently, and the processing speed of the data rotation unit 11 when the work memory 53 is shared can be increased.

  The right to use the work memory 53 is set in the register 35 (see FIG. 3). The use right is written to the register 35 by the control unit 4 (see FIG. 1) in response to the multi-access request. The control unit 4 includes a CPU (not shown).

  The first and second rotation processing units 51 and 52 perform processing for the number of data blocks that are sequentially set based on the setting of the register 35. In this case, when the processing of one rotation processing unit is completed, the right to use the work memory 53 is transferred to the other rotation processing unit.

  FIG. 10 is an explanatory diagram showing an outline of the sharing operation of the work memory 53 by the first rotation processing unit 51 and the second rotation processing unit 52. For example, in the register 35, when the number of processing data blocks of the first rotation processing unit 51 is set to 8 and the number of processing data blocks of the second rotation processing unit 52 is set to 2, as shown in FIG. First, the first rotation processing unit 51 obtains the right to use the work memory 53 and performs rotation processing of 8 data blocks, and then the second rotation processing unit 52 obtains the right to use the work memory 53 to obtain 2 data blocks. The rotation process is performed. By repeating this operation alternately, the processing for one page is completed.

  FIG. 11 shows the right to use the work memory 53 for each image format necessary for rotating the image data of one data block as the number of continuous acquisitions of the work memory 53.

  Referring to FIG. 11, for example, multi-access accompanied by a request for rotation processing of image data is performed by scanner unit 1 (RGB (24-bit) data rotation processing request) and printer unit 2 (CMYK (4-bit) data rotation processing request). The time-division use of the work memory 53 when it occurs will be described.

  In this case, 128 pixels (384 bytes) × 64 lines, which is the block size of the scanner unit 1, are continuously rotated 64 times, and then the block size of the printer unit 2 is 256 pixels (128 bytes) × 256 lines. Rotate 32 times continuously. As a result, 100 MB data is transferred from the scanner unit 1 to the large capacity memory 3 at a speed of 80 PPM with rotation, and 66 MB data is transferred from the large capacity memory 3 to the printer section 2 at a speed of 80 PPM with rotation. can do.

  12 to 15 compare the usage forms of the work memory 53 in a plurality of data rotation units 11 having different configurations. In FIG. 12, the data rotation unit 11 includes only one work memory 53, and the work memory 53 is shared by the first rotation processing unit 51 and the second rotation processing unit 52, but time division use is not performed. It is explanatory drawing of. FIG. 13 is an explanatory diagram when the data rotation unit 11 includes a dedicated work memory 53 for each of the first rotation processing unit 51 and the second rotation processing unit 52. FIG. 14 is an explanatory diagram in the case where the data rotation unit 11 includes only one work memory 53, and the work memory 53 is shared by the first rotation processing unit 51 and the second rotation processing unit 52 by time division use. is there. In FIG. 15, the data rotation unit 11 includes only one work memory 53, the work memory 53 is shared by the first rotation processing unit 51 and the second rotation processing unit 52 by time division use, and the first rotation is performed. It is explanatory drawing when the ratio of the usage time of the work memory 53 is not equal by the process part 51 and the 2nd rotation process part 52, and is deviating to one side.

  In the operation of the data rotation unit 11 shown in FIGS. 12 to 15, the first rotation processing unit 51 is between the first preprocessing by the first preprocessing unit 12 and the first postprocessing by the first postprocessing unit 13. The rotation processing is performed, and the second rotation processing unit 52 performs the rotation processing between the second preprocessing by the second preprocessing unit 14 and the second postprocessing by the second postprocessing unit 15.

  In the operation of FIG. 12, since only one work memory 53 is not shared by the first rotation processing unit 51 and the second rotation processing unit 52, for example, the first preprocessing unit 12 performs image data for one page by the first preprocessing unit 12. One pre-processing (first pre-), rotation processing (rotation) by the first rotation processing unit 51, and first post-processing (first post-processing) by the first post-processing unit 13 are completed, for example, image data for one page Second pre-processing (second pre-) by the second pre-processing unit 14, rotation processing (rotation) by the second rotation processing unit 52, and second post-processing (second post-) by the second post-processing unit 15 are performed. Is called. Therefore, as described above, the configuration in which the number of work memories 53 is simply reduced causes the processing speed of the image processing unit 5 to decrease.

  In the operation of FIG. 13, the first rotation processing unit 51 and the second rotation processing unit 52 perform rotation processing using the dedicated work memory 53, respectively, whereby the first preprocessing unit 12 and the first rotation processing unit. 51 and the processing by the first post-processing unit 13 and the processing by the second pre-processing unit 14, the second rotation processing unit 52, and the second post-processing unit 15 can be performed in parallel. Therefore, the image processing unit 5 can maintain a desired processing speed. However, since the first rotation processing unit 51 and the second rotation processing unit 52 are each provided with the dedicated work memory 53, the number of work memories 53 increases, resulting in an increase in cost.

  In the operation of FIG. 14, the first rotation processing unit 51 and the second rotation processing unit 52 use one work memory 53 in a time-sharing manner. Specifically, as shown in FIG. 14, the first rotation processing unit 51 rotates the data block processed by the first preprocessing unit 12 and passes it to the first post-processing unit 13. When the rotation processing by the first rotation processing unit 51 is completed, the second rotation processing unit 52 rotates the data block processed by the second preprocessing unit 14 and passes it to the second post-processing unit 15.

  For example, the first preprocessing unit 12 sequentially processes four data blocks, and the first rotation processing unit 51 sequentially rotates the four data blocks. The processing time in the first rotation processing unit 51 is shorter than the processing time in the first rotation processing unit 51. The data block rotation processing is performed in the first rotation processing unit 51, for example, a filter. This is because the process is completed in a shorter time than the processing.

  In the above operation, the processing by the first preprocessing unit 12 and the processing by the second preprocessing unit 14 can be performed in parallel. Therefore, the image processing unit 5 can reduce the circuit scale and the cost by reducing the work memory 53 while maintaining a desired processing speed.

  In the operation of FIG. 15, the first rotation processing unit 51 and the second rotation processing unit 52 use one work memory 53 in a time-sharing manner. This is the same as the operation of FIG. However, the ratio of the usage time of the work memory 53 between the first rotation processing unit 51 and the second rotation processing unit 52 is not the same but is biased to one side. This is due to the following reason.

  In a digital copying machine, a processing speed corresponding to the format of image data to be processed is required. That is, in a digital copying machine, for example, the copying speed of a monochrome image is required to be about three times the copying speed of a color image, which is usually such a specification. Therefore, the usage time ratio of the work memory 53 is set in accordance with such specifications. That is, the first preprocessing unit 12, the first rotation processing unit 51, and the first post-processing unit 13, the second pre-processing unit 14, the second rotation processing unit 52, and the second post-processing unit 15. When the format of image data to be processed is different between the second processing unit consisting of the first processing unit (first rotation processing unit 51) and the second processing unit (second rotation processing unit 52) according to the format of the image data. ) To set the ratio of the usage time of the work memory 53.

  The setting of the ratio of the usage time is performed by the control unit 4. In this case, for example, the control unit 4 receives an input requesting a color copy of the user on the operation panel of the digital copying machine (for example, processing by the first processing unit) or a personal computer connected to the digital copying machine. The above setting is performed based on a monochrome printing request (for example, processing by the second processing unit). Further, the control unit 4 performs this setting by calculation or referring to a table created in advance.

  FIG. 15 shows an example in which RGB data is processed in the first processing unit (first rotation processing unit 51) and monochrome data is processed in the second processing unit (second rotation processing unit 52). . Here, if the usage time of the work memory 53 is set equally between the first rotation processing unit 51 and the second rotation processing unit 52, the RGB data (24 bits) is eight times as many times as the monochrome data (1 bit). Therefore, the RGB data processing speed by the first rotation processing unit 51 is low, while the monochrome data processing speed by the second rotation processing unit 52 is high. Therefore, the ratio of the usage time of the work memory 53 between the first rotation processing unit 51 and the second rotation processing unit 52 is set to 2: 1.

  Specifically, for example, when RGB (24 bit) image data is rotated in block units of 16 horizontal pixels × 16 vertical pixels, the work memory 53 requires a 786-byte RAM area. When this RAM area is used, it is possible to rotate 48 (horizontal) × 16 (vertical) pixels for monochrome (1 bit) image data. If the image data to be processed is, for example, A4 size 600 dpi, the image data is 4960 pixels wide × 7015 pixels high. Therefore, for these RGB (24 bit) image data and monochrome (1 bit) image data, the rotation processing of 90 degrees or 270 degrees is completed by performing the following number of times processing.

RGB (24-bit) image data: 4960/16 × 7015/16 = 136,090 (times)
Monochrome (1 bit) image data: 4960/48 x 7015/16 = 17,121 (times)
In the above operation, the processing by the first preprocessing unit 12 and the first rotation processing unit 51 and the processing by the second preprocessing unit 14 and the second rotation processing unit 52 can be performed in parallel. Therefore, the image processing unit 5 can reduce the circuit scale and cost by reducing the work memory 53 while maintaining a desired processing speed.

  Further, when the data amount of the image data processed by the first rotation processing unit 51 and the second rotation processing unit 52 is different, for example, when the format of the image data is different, the data amount (format of the image data to be processed) ), The ratio of the usage time of the work memory 53 between the first rotation processing unit 51 and the second rotation processing unit 52 is set. Accordingly, there is no processing time imbalance such that one of the first rotation processing unit 51 and the second rotation processing unit 52 ends significantly earlier and the other ends significantly later. That is, when processing image data in parallel between the first processing unit and the second processing unit, for various image data having different data amounts (formats), the specification of the processing time ratio between the image data Processing that conforms to can be performed.

  In the digital copying machine of the present embodiment, processing including rotation of image data is performed in parallel in the first processing unit and the second processing unit in the following case. For example, the image data of the original read by the canner unit 1 is rotated and stored in the large-capacity memory 3, and the specified image data stored in the large-capacity memory 3 is rotated and output. In this case, the printer unit 2 performs printing in parallel.

  When the printer unit 2 prints image data, as described above, in addition to printing the image data read from the large-capacity memory 3, as shown in FIG. In some cases, image data received from a plurality of external devices connected via the H.63, for example, a personal computer (personal computer) 62 is printed.

  In the configuration shown in FIG. 16, the image data received from the personal computer 62 can be rotated by the first rotation processing unit 51 or the second rotation processing unit 52 and stored in the large-capacity memory 3.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims. That is, embodiments obtained by combining technical means appropriately changed within the scope of the claims are also included in the technical scope of the present invention.

1 is a block diagram showing a schematic configuration of a digital copying machine having an image data rotation processing function as an image processing apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram illustrating in detail a configuration of an image processing unit illustrated in FIG. 1. FIG. 3 is a block diagram illustrating in detail a configuration of a data rotation unit illustrated in FIG. 2. It is explanatory drawing which shows the outline | summary of the rotation process of the image data in the data rotation part shown in FIG. It is explanatory drawing which shows in detail the rotation process shown in FIG. 4 including the process on a work memory. 6A is an explanatory diagram showing a writing process to the work memory and a reading process from the work memory when the work memory shown in FIG. 5 is used without being divided, and FIG. 6B is a work memory. It is explanatory drawing which shows the write-in process to the work memory in the case of using and dividing, and the read-out process from a work memory. FIG. 7A is an explanatory diagram showing the writing process to the work memory shown in FIG. 2 when the image data to be processed is RGB (24 bit) bit data, and FIG. FIG. 7C is an explanatory diagram showing the writing process to the work memory when the image data to be processed is K (1 bit) data. It is. FIG. 3 is an explanatory diagram showing the number of pixels for each image format that can be stored in the work memory when the work memory shown in FIG. 2 has a configuration of 2048 words × 32 bits × 4. It is explanatory drawing which shows the data size (data amount) for every image format in A4 size 600dpi. It is explanatory drawing which shows the outline | summary of the sharing operation | work of the work memory by the 1st rotation process part shown in FIG. 2, and a 2nd rotation process part. It is explanatory drawing which shows the use right of the work memory shown in FIG. 2 for every image format required when image data of 1 data block is rotated as the frequency | count of continuous acquisition of a work memory. In the data rotation unit shown in FIG. 2, only one work memory is shared by the first rotation processing unit and the second rotation processing unit, and the operation of the data rotation unit when it is not used in a time-sharing manner is explained. It is. FIG. 5 is an explanatory diagram showing an operation of the data rotation unit in the case where the data rotation unit shown in FIG. 2 includes a dedicated work memory in the first rotation processing unit and the second rotation processing unit. FIG. 3 is an explanatory diagram showing an operation of the data rotation unit when only one work memory is shared by the first rotation processing unit and the second rotation processing unit by time division use in the data rotation unit shown in FIG. 2. In the data rotation unit shown in FIG. 2, only one work memory is shared by the first rotation processing unit and the second rotation processing unit by time division use, and the first rotation processing unit and the second rotation processing unit FIG. 5 is an explanatory diagram showing the operation of the data rotation unit when the ratio of the usage time of the work memory is not uniform and is biased to one side. 1 is a schematic block diagram illustrating a system including a digital copying machine as an image processing apparatus according to an embodiment. It is explanatory drawing which shows the outline | summary of the rotation process in the case of rotating the image data by the conventional digital copying machine 90 degree | times. FIG. 10 is a schematic block diagram showing a configuration for performing image data rotation processing in a conventional digital copying machine. It is a block diagram which shows the structure of the image processing part shown in FIG. 18 in detail. FIG. 20 is a block diagram illustrating in detail the configuration of a first data rotation unit and a second data rotation unit illustrated in FIG. 19.

Explanation of symbols

1 Scanner section (original image reading means)
2 Printer section (printing means)
3 Large capacity memory (image data storage memory)
4 control unit (time division use control unit)
5 Image processing unit 11 Data rotation unit 12 First pre-processing unit 13 First post-processing unit 14 Second pre-processing unit 15 Second post-processing unit 16 Bus arbitration unit (time division use control unit)
51 First Rotation Processing Unit 52 Second Rotation Processing Unit 53 Work Memory (Rotation Image Memory)

Claims (10)

An image memory for rotation,
Using the same image memory for rotation, the image data is rotated by changing the reading order of the image data from the image memory for rotation with respect to the order of writing the image data to the image memory for rotation. The first and second rotation processing units for performing the rotation processing by dividing the image data into a plurality of blocks;
An image processing apparatus, comprising: a time-division use control unit that causes the rotation image memory to be used in a time-sharing manner by the first rotation processing unit and the second rotation processing unit in the rotation process.   The time-sharing use control unit is responsive to a data amount of the first image data rotated by the first rotation processing unit and a data amount of the second image data rotated by the second rotation processing unit. The image processing apparatus according to claim 1, wherein a ratio of time division use of the image memory for rotation between the first rotation processing unit and the second rotation processing unit is set.   When one of the first image data and the second image data is color image data and the other is monochrome image data, the time-division use control unit performs the first rotation. Of the processing unit and the second rotation processing unit, the rotation image by the rotation processing unit that processes monochrome image data is the time-division use ratio of the image memory for rotation by the rotation processing unit that processes color image data. The image processing apparatus according to claim 2, wherein the image processing apparatus is larger than a ratio of time division use of the memory.   When the first image data and the second image data are color image data having the same data amount or monochrome image data having the same data amount, the time-division use control unit is configured to perform the first rotation. The image processing apparatus according to claim 2, wherein a ratio of time division use of the image memory for rotation by the processing unit and the second rotation processing unit is made equal.   3. One of the first image data and the second image data is color image data in RGB signal format, and the other is color image data in CMYK signal format. An image processing apparatus according to 1. Data can be transmitted / received to / from a document image reading unit that reads an image of a document and acquires image data,
It has a memory for storing image data,
The first rotation processing unit rotates the image data input from the document image reading unit and stores the image data after the rotation processing in the image data storage memory, while the second rotation processing unit The image processing apparatus according to claim 1, wherein the image data read from the image data storage memory is rotated and then stored in the image data storage memory. Data can be sent to and received from a printing means that performs printing based on image data.
The image processing apparatus according to claim 6, wherein the second rotation processing unit performs the rotation processing according to a printing operation of the printing unit.   An image reading apparatus comprising the original image reading means and the image processing apparatus according to claim 6. The document image reading means and the image processing apparatus according to claim 6, and printing means for performing printing based on image data,
The image forming apparatus, wherein the second rotation processing unit performs the rotation processing in accordance with a printing operation of the printing unit. Using the same image memory for rotation, rotating the image data by changing the reading order of the image data from the image memory for rotation relative to the order of writing the image data to the image memory for rotation, Having first and second rotation processing steps for performing the rotation processing by dividing the image data into a plurality of blocks;
An image processing method characterized in that in the rotation processing, the image memory for rotation is used in a time division manner in the first rotation processing step and the second rotation processing step.

Images