JP4956282B2 - Image processing device - Google Patents

Description

  The present invention relates to an image processing apparatus such as an image forming apparatus (digital multifunction peripheral, digital copying machine, facsimile apparatus, printer, etc.), image reading apparatus (scanner apparatus, etc.), personal computer (hereinafter abbreviated as “PC”).

For example, an image processing apparatus such as a digital multi-function peripheral that reads image data of a document by a reading unit (image reading means) and prints an image by a writing unit (image forming means) based on the image data. The image data is variously processed by the image processing unit.
In such an image processing apparatus, in recent years, the demand for image quality has become stricter, and in order to realize high image quality, memory capacity has increased and circuits have become more complex. Further, in the image processing, since the calculation is performed on the target pixel using surrounding pixels in the main scanning direction and the sub-scanning direction orthogonal thereto, the FIFO (First In) corresponding to the image size (image data size) in the main scanning direction is performed. First Out (memory) (hereinafter, also simply referred to as “FIFO”) is required in a plurality of stages, and the number of FIFO stages is also increasing for higher image quality.

However, for example, when the original to be read is a wide machine such as an A0 size, the required memory capacity becomes enormous, and having a FIFO of the same size in the ASIC (Application Specific Integrated Circuit) is practical in terms of yield and cost. Not right. Further, when scaling processing such as enlargement processing is performed, the required FIFO capacity is further increased.
Therefore, there is a need for a technique that can perform image processing on an image having a document size exceeding the FIFO size while minimizing the FIFO size. For this purpose, the image data transferred from the reading unit is once stored in the external memory, and the image data is divided into rectangles and transferred to the subsequent module in a size determined by the capacity of the FIFO and the magnification.

However, if the image data of each page divided into rectangles is sequentially subjected to a scaling process of an arbitrary size in the main scanning direction, the image size after scaling for the image data of each page does not become a good size for separation. In some cases, there is a problem that the circuit for adjusting the joint portion of the page becomes complicated when each image data is transferred to the outside.
Therefore, as shown in Patent Document 1, when the image size of the image data (rectangular region) of the page divided into rectangles is changed to a value that has a fractional part after the decimal point, An image processing apparatus has been proposed in which the number of pixels is adjusted by rounding up or down the decimal part at the joint portion of each rectangular area to adjust the final size to a desired scaling size.
Japanese Patent Laid-Open No. 2004-220484

However, in the device described in Patent Document 1, there is a possibility that an adverse effect on image quality (such as streaking) may appear at the joint portion of each rectangular area due to truncation / rounding up after the decimal point caused by scaling processing. Further, depending on the image size after scaling, the image transfer efficiency is deteriorated.
The present invention has been made in view of the above problems, and is intended to prevent image quality degradation at a low cost when image data of a rectangularly divided page is subjected to scaling processing and transferred to the outside. Objective.

The present invention includes a rectangular dividing unit that divides image data into a plurality of pages, a scaling processing unit that performs a scaling process in the main scanning direction on the image data of the page that has been rectangularly divided by the rectangular dividing unit , An image processing apparatus having image transfer means for transferring the image data scaled by the scaling process means to the outside. In order to achieve the above object, the image processing apparatus is characterized as follows.

The image processing apparatus according to the invention of claim 1, when the image data of the rectangle divided page is transferred to the outside by the image transfer means via said scaling processing unit by said block dividing means, said variable power main scanning direction size of the image data from the processing means, when not an integer multiple of the boundary size is the number of pixels of the set value corresponding to the condition of the image transfer in the image transfer means, to an integral multiple of the boundary size The image data up to the maximum main scanning length is transferred, the remaining pixels are discarded , and at least the number of pixels before scaling used for the previous image transfer is held until the image data transfer period of the next page. When transferring image data, based on the number of pixels before scaling, the scaling processing is performed on the next page of image data that is traced back to the number of discarded pixels. It is provided with a control means for controlling to transfer to the outside via the stage.

Invention an image processing apparatus according to claim 2, the boundary size definitive to the image processing apparatus according to claim 1 is one that is set value of the number of pixels calculated from the bus width of the image transfer bus.
The image processing apparatus according to the invention of claim 3, the boundary size definitive to the image processing apparatus according to claim 1 is one that is set value of the number of pixels calculated from the burst length of the burst transfer.

Invention an image processing apparatus according to claim 4, Oite to any one of the image processing apparatus of claim 1, said control means is the image data before the scaling processing to be inputted to the scaling processing unit The main scanning counter before scaling for counting the number of pixels in the main scanning direction of the image data of the page divided into rectangles by the rectangular dividing means, and transferred to the outside after the scaling processing in the main scanning direction by the scaling processing means. The main scanning counter after scaling that counts the number of pixels in the main scanning direction of the image data, the boundary size register that holds the boundary size, and the maximum value that the value of the main scanning counter after scaling is the integer multiple of the boundary size Upon detecting that the value of the main scanning length, and holds the value, and the zooming value before the main scan counter of the variable power after the main scanning counter at that time, the block dividing means those values Therefore and a counter register for holding up the rectangular split transfer to an external image data of the next page is completed, when the transfer of image data of the next page, the transfer from the values which the counter register holds The image data to be determined is determined .

The image processing apparatus according to the invention of claim 5, Oite the image processing apparatus according to claim 4, said image transfer means has a part of the control means, the value after the scaling main scanning counter the boundary The value of the main scanning counter after scaling when the maximum main scanning length is a value that is an integral multiple of the size is received, and among the image data received from the scaling processing means, the value of the main scanning counter after scaling An image processing apparatus that transfers image data of a size in a main scanning direction up to a value to the outside.

The image processing apparatus according to the invention of claim 6, Oite to any of the image processing apparatus of claim 1, said control means, storage means for storing image data after the magnification change processing by the scaling processing unit the have the image data stored in the storage means when transferring to said image transfer means, the image data intended to be transferred to the maximum the image transfer means to the main scanning length of an integral multiple of the boundary size is there.

According to the present invention, when the image processing apparatus transfers image data of a page divided into rectangles to the outside by the image transfer unit via the scaling processing unit, the image data from the scaling processing unit is main. When the size in the scanning direction does not become an integral multiple of the boundary size , which is the set value of the number of pixels according to the image transfer conditions in the image transfer means , image data up to the maximum main scanning length that is an integral multiple of the boundary size When the image data of the next page is transferred, the remaining pixels are cut off from the image data traced back to the number of pixels of the previous page by the number of discarded pixels. By controlling the image data to be transferred to the outside, it is possible to prevent image quality degradation at a low cost when the image data of the page divided into rectangles is subjected to a scaling process and transferred to the outside.

Hereinafter, the best mode for carrying out the present invention will be specifically described with reference to the drawings.
[Hardware configuration example of a digital MFP]
First, a hardware configuration of a digital multi-function peripheral (hereinafter also referred to as “MFP”) which is an image processing apparatus in this embodiment will be described with reference to FIG. Instead of the MFP, another image forming apparatus such as a digital copying machine or a facsimile apparatus having a scanner function and a printer function may be used.

FIG. 1 is a block diagram showing a hardware configuration example of an MFP according to an embodiment of the present invention.
The MFP 100 is an image forming apparatus capable of realizing various functions including functions as a digital copying machine, a printer, a facsimile machine, and a scanner, that is, a copy function, a document storage (document box) function, a facsimile function, a printer function, and a scanner function. As shown in FIG. 1, the engine unit 110 and the controller 120 are included. These configurations are hardware resources for performing image processing such as image reading, printing (image formation), and image information transmission / reception of a document.

The engine unit 110 includes a CPU 111, a reading unit 112, a writing unit 113, an ASIC (Application Specific Integrated Circuit) -E 114, and an external memory 118.
The CPU 111 is a microcomputer that comprehensively controls the entire engine unit 110 via the ASIC-E 114, and includes a central processing unit, a program ROM, a RAM, and the like. The central processing unit of the CPU 111 can function as a boundary size setting unit by executing a program in the program ROM.
The reading unit 112 is an image reading unit such as a scanner that reads an image of a document as image data.

The writing unit 113 is an image forming unit such as a plotter that prints image data read by the reading unit 112 or image data received from an external device on a sheet (other recording medium) as a visible image.
The ASIC-E 114 is a device board having an image processing unit 115 and an image interface (hereinafter, “interface” is also referred to as “I / F”) unit 117. The ASIC-E 114 is configured to share a device to be controlled by the CPU 111. In view of the above, it is intended to support the improvement of the efficiency of development of application programs (hereinafter also simply referred to as “applications” or “applications”).

The image processing unit 115 performs image processing to be described later on image data read by the reading unit 112 or image data to be transferred to the writing unit 113.
The image I / F unit 117 is an image transfer unit that controls transmission / reception (transfer) of image data between the image processing unit 115 and the controller 120.
The external memory 118 is a recording medium such as an HDD (hard disk device) or a memory card.

The controller 120 controls each part of the MFP 100 in an integrated manner. Various functions can be realized by the control.
The controller 120 includes an operation unit 121, HDD 122, CPU 123, ASIC-C 124, MEM-C 127, NB 128, MEM-P 129, ASIC 130, OPTION 131, 132, SB 133, and ROM 134. Note that the operation unit 121 is actually disposed outside the controller 120.

The operation unit 121 includes various operation keys (“operation switch” or “operation” for inputting data such as operation instructions (operation requests) to the engine unit 110 and external devices based on the selection of the image processing function provided by the MFP 100. It is also an operation means having a display device such as an LCD or a CRT.
The HDD 122 is a storage unit for accumulating and storing various data such as image data and programs (software).

The CPU 123 is a microcomputer that comprehensively controls the entire controller 120, and includes a central processing unit, a program ROM, a RAM, and the like.
The ASIC-C 124 is a device board having a rotator 125 and an editor 126.
The rotator 125 performs a rotation process on the image data read by the reading unit 112 or the image data to be transferred to the writing unit 113.

The editor 126 performs an editing process such as scaling on the image data read by the reading unit 112 or the image data to be transferred to the writing unit 113.
The MEM-C 127 is a storage unit such as a RAM for temporarily storing image data read by the reading unit 112.
The NB 128 is a north bridge for connecting the CPU 123 to the ASIC-C 124, MEM-P 129, and SB 133.
The MEM-P 129 is a storage unit such as a RAM used for developing image data to be transferred to the engine unit 110.

The SB 133 is a south bridge for connecting the NB 128 and peripheral devices (ASIC 130, OPTION 131, 132).
The ROM 134 is a memory that stores a program (including a boot program) used when the CPU 123 controls the MFP 100.

[Specific configuration example of engine section]
Next, a specific configuration of the engine unit 110 of FIG. 1 will be described with reference to FIG.
FIG. 2 is a block diagram showing a specific configuration example of the engine unit 110 of FIG.
The image processing unit 115 includes a scanner image processing unit 115a and a printer image processing unit 115b.

The scanner image processing unit 115a performs shading correction, reading γ correction, MTF correction, and the like on the R, G, and B image data read from the original by the reading unit 112, and the corrected R, G, and B of the image data. The image data is converted into C, M, Y, K image data.
The printer image processing unit 115b reads the C, M, Y, and K image data from the image I / F unit 117 into the writing units 113a, 113b, 113c, and 113d of the C, M, Y, and K colors of the writing unit 113. Are converted into C, M, Y, and K image data suitable for the image expression characteristics. In “R, G, B”, R represents red, G represents green, and B represents blue. In “C, M, Y, K”, C represents cyan, M represents magenta, Y represents yellow, and K represents black.

[Configuration example of scanner image processing unit]
Next, the configuration and control of the scanner image processing unit 115a in FIG. 2 will be described with reference to FIG.
FIG. 3 is an explanatory diagram showing an example of the configuration and data flow of the scanner image processing unit 115a of FIG.

  The scanner image processing unit 115a of the ASIC-E 114 includes an input I / F unit 201, an asynchronous absorption FIFO memory (hereinafter simply referred to as “FIFO”) 202 and 203, an external memory I / F unit 204, a preprocessing unit 205, a filter. A processing unit 206, a scaling processing unit 207, and the like are included. The scanner image processing unit 115a can function as a rectangle dividing unit, a scaling unit, a control unit, and a line gate signal output unit.

Next, each embodiment of the configuration related to the present invention in MFP 100 configured as described above will be specifically described with reference to FIGS.
[First embodiment]
First, the first embodiment will be described.
When the scanner image processing unit 115a shown in FIG. 3 receives image data from the reading unit 112 in the original image size (actually the main scanning size that is the size in the main scanning direction), the image data is input I / F. The data is stored in the external memory 118 via the unit 201, the FIFO 202, and the external memory I / F unit 204.

FIG. 4 is an explanatory diagram showing an example of margins for each image size after division when performing rectangular division processing on image data on the external memory 118.
When rectangular division processing is performed on image data on the external memory 118, if the divided rectangular regions are transferred as they are, the boundary portion is streaked in the image processing of the filter unit 206 and the like, and the image quality deteriorates. Therefore, the image data needs to be fogged and read from the external memory 118 so that the image quality does not deteriorate.

  Therefore, when transferring the image data stored in the external memory 118 to the subsequent module, for example, when the rectangular division as shown in FIG. 4 is used, the first page has a main scanning length (length in the main scanning direction) “X1 + 304” pixels. The sub-scan length (length in the sub-scan direction) is read from the external memory 118 as “Y1 + 3” pixels. The “+304” pixel in the main scanning length and the “+3” pixel in the sub-scanning length indicate the size at which image data is overlapped so that image quality degradation such as streak does not occur at the boundary between pages in the image processing of the subsequent module. . The main scanning length must be less than the line buffer size of the subsequent module. The size of the next page to be transferred is the main scanning length “X2 + 304 + 304” pixels and the sub-scanning length “Y1 + 3” pixels.

Normally, the image forming apparatus such as the MFP 100 or the copying machine has a function of enlarging / reducing (enlarging or reducing) image data of a document and printing it on a recording material such as paper as a visible image. Even when the data is divided into rectangles and transferred, enlargement / reduction is performed using the scaling unit.
The effective image areas in the main scanning direction (hereinafter simply referred to as “image effective areas”) in the preprocessing unit 205, the filter processing unit 206, and the scaling processing unit 207 of the scanner image processing unit 115a shown in FIG.

  FIG. 5 shows an example of the relationship between the divided rectangular area shown in FIG. 4 and each gate signal corresponding to the image effective area to each module (the preprocessing unit 205, the filter processing unit 206, and the scaling processing unit 207). It is explanatory drawing shown. The gate signal includes a line gate signal and a frame gate signal. The line gate signal is a signal for controlling writing of image data in the main scanning direction. The frame gate signal is a signal for controlling writing of image data in the sub-scanning direction.

In the preprocessing unit 205 and the filter processing unit 206 (hereinafter also referred to as “filter processing unit 206 etc.”), the external memory 118 is used to prevent image quality degradation such as page breaks when image processing is performed on image data. The image data read out from each other is overlapped between the pages, but this size becomes the effective image area in the filter processing unit 206 and the like. A gate signal of an image size (an area where image processing is correctly performed) to be actually transferred to the subsequent module (on the controller 120 side) is issued to the scaling processing unit 207.
The scaling processing unit 207 enlarges / reduces the image data from the filter processing unit 206 in the main scanning direction according to an arbitrary scaling ratio set by software (actually by the CPU 111 operating according to the software). Processing (main scanning arbitrary scaling) is performed.

FIG. 6 is a diagram for explaining 150% (enlargement) and 67% (reduction) scaling processing in the main scanning direction performed by the scaling unit 207 on the image data.
FIG. 7 shows an image effective area of each module, that is, the number of pixels necessary for the filter processing unit 206 and the like (effective region), the number of input pixels to the scaling processing unit 207 (effective region), and the scaling by the scaling processing unit 207 6 is a conceptual diagram for explaining an example of the number of pixels after and an image size output from the image I / F unit 117 to the controller 120. FIG.
Figure 8 is a truncation of the remaining pixels, such tinged be an integral multiple of the boundary size, which is the set value of the number of pixels corresponding to the conditions of the image transfer in the image I / F unit 117 (hereinafter simply referred to as "boundary size") FIG. 6 is a diagram for explaining a method for adding the truncated pixels on the next page.

The scaling processing unit 207 performs scaling processing by calculating virtual pixels for pixels (input pixels) of input image data.
In the example of FIG. 6, with respect to pixels (input pixels) A to E of input image data, 1 to 7 virtual pixels are generated at 150% enlargement, and 1 to 3 virtual pixels are generated at 67% reduction. .
Then, for example, as shown in FIG. 7, if data having a main scanning length of 6,000 pixels is input to the scaling processing unit 207, the number of pixels after the 67% scaling processing is 4,020 pixels. If the boundary size is 512 pixels in the transfer from the image I / F unit 117 to the controller 120 side, as shown in FIG. 8, the main scanning size (image size) after scaling processing is 512 * 7 = If it is 3,584 pixels (the number of pixels of the maximum main scanning length that is an integral multiple of the boundary size) , the circuit configuration becomes easy. Therefore, 4,020-3,584 = 436 pixels are discarded.

The scaling processing unit 207 holds the information on the number of pixels before scaling and the fractional number used for the previous image transfer (image data transfer) until the image transfer period of the next page, and stores the number of pixels information externally. By notifying the memory I / F unit 204, the image data is fetched from the external memory 118 by going back to the image effective area of the next page by tracing back the area that was discarded when transferred from the image I / F unit 117 to the controller 120, The truncated image data can be transferred on the next page .

As described above, when the scanner image processing unit 115 a transfers the image data of the divided pages to the external controller 120 via the scaling processing unit 207 and the image I / F unit 117, the scaling processing unit 207. When the main scan size of the image data from is not an integral multiple of the boundary size for the image I / F unit 117 , pixels up to the maximum main scan length that is an integral multiple of the boundary size are transferred, and the remaining pixels are By performing the control so as to cut down, the transfer size of the image data in the main scanning direction can be matched with the boundary size for the image I / F unit 117, so that the circuit configuration of the image I / F unit 117 can be simplified. That is, it is possible to prevent image quality degradation at a low cost when the image data of a page divided into rectangles is scaled and transferred to the controller 120.

[Second Embodiment]
Next, a second embodiment will be described.
In the second embodiment, the following configuration is added to the configuration of the first embodiment.
The CPU 111 (software) in FIG. 1 can set the boundary size according to an instruction from the outside (the operation unit 121 or an external device such as a PC). As a result, the scanner image processing unit 115a, which is hardware, can discard pixels that have not become an integral multiple of the boundary size based on the set value.
Therefore, the hardware circuit configuration is simplified to the extent that the boundary size need not be calculated by hardware.

[Third embodiment]
Next, a third embodiment will be described.
In the third embodiment, the following configuration is added to the configuration of the first embodiment.
The scanner image processing unit 115a (hardware) can automatically calculate the boundary size based on a predetermined condition.

That is, since the image transfer from the image I / F unit 117 serving as the image transfer means to the controller 120 side is performed using the bus, the bus width to be used is switched depending on the operation mode. Is fixed. The burst length for burst transfer can also be set. Therefore, before the actual image transfer is performed, it becomes possible for the scanner image processing unit 115a to calculate the boundary size from such information ( image transfer conditions) using a multiplication circuit or the like.
Therefore, the software configuration is simplified because it is not necessary to have information on image transfer conditions such as the hardware bus width and burst length.

[Fourth embodiment]
Next, a fourth embodiment will be described.
The fourth embodiment is obtained by adding the following configuration to any configuration of the first to third embodiments.

  The main scanning arbitrary scaling processing module in the scaling processing unit 207 in FIG. 3 is the image data of the page divided into rectangles which is the image data before the main scanning scaling processing input to the main scanning arbitrary scaling processing module. A main scanning counter before scaling that sequentially counts the number of pixels in the main scanning direction (main scanning size before scaling), and the number of pixels in the main scanning direction of image data transferred to the subsequent module after the main scanning scaling process A post-magnification main scan counter that counts the post-magnification main scan size), a boundary size register that holds a boundary size (setting value) for image transfer from the image I / F unit 117 to the controller 120, and a post-magnification main scan And a counter register for holding the value of the scanning counter and the value of the main scanning counter before magnification.

  The pre-magnification main scanning counter counts up while the line gate signal input to the main scanning arbitrary magnification processing module is asserted. The post-magnification main scan counter counts up while the line gate signal output from the magnification processing unit 207 to the subsequent module is asserted.

When the main scanning arbitrary scaling processing module detects that the value of the main scanning counter after scaling is the maximum main scanning length value that is an integral multiple of the setting value of the boundary size register, the main scanning after scaling is performed at that time. The counter value and the pre-magnification main scanning counter value are held in the counter register, and when the line gate signal is negated, the transfer of the image data of the next page divided into rectangles to the controller 120 ends. Hold until.

When transferring the image data of the next page divided into rectangles, the filter processing or the like is performed based on the post-magnification main scan counter value and the pre-magnification main scan counter value held in the counter register on the previous page. The image data to be transferred is determined and read from the external memory 118 in consideration of the margin amount that does not affect the image quality in the image processing.
With such a configuration, it is possible to reliably prevent deterioration in the image quality of the joint portion between the rectangular areas when transferring the image data of the rectangular areas (rectangular divided pages).
[Fifth embodiment]
Next, a fifth embodiment will be described.
The fifth embodiment is obtained by adding the following configuration to the configuration of the fourth embodiment.

The main scanning arbitrary scaling processing module in the scaling processing unit 207 in FIG. 3 counts the main scanning size after the scaling processing, so that the image data after the scaling processing is processed at the timing when the line gate signal is negated. The maximum main scanning size (the value of the main scanning counter after scaling) that is an integral multiple of the boundary size is known. When this information is received by the image I / F unit 117 and actually transferred from the image I / F unit 117 to the controller 120, image data corresponding to the main scanning size up to the value of the main scanning counter after scaling is obtained. Is transferred, and the remaining part is not transferred (truncated). In this case, all the image data after the scaling process is transferred to the image I / F unit 117.

As described above, the image I / F unit 117 receives the value of the main scanning counter after scaling when the value of the main scanning counter after scaling reaches the maximum main scanning size value that is an integral multiple of the boundary size. The image data for the main scanning size up to the value of the main scanning counter after scaling among the image data received from the scaling processing unit 207 is transferred to the controller 120, whereby the boundary size for the image I / F unit 117 is transferred. Only the image data up to the maximum main scanning size which is an integral multiple of can be reliably transferred.

[Sixth embodiment]
Next, a sixth embodiment will be described.
The sixth embodiment is obtained by adding the following configuration to any one of the first to fourth embodiments.

The main scanning arbitrary scaling processing module of the scaling processing unit 207 in FIG. 3 performs the main scanning scaling processing when the main scanning scaling processing (magnification processing in the main scanning direction) is performed on the input image data. A line buffer (storage means) for storing the image data (line data) after the magnification processing is provided, and the image data after the main scanning scaling processing is once stored in the line buffer. After that, the image data in the line buffer is read out and transferred to the image I / F unit 117, so that the main scan size of the image data after the scaling process is also known. Therefore, the boundary size of the image I / F unit 117 ( By transferring the image data up to the maximum main scanning length which is an integral multiple of the boundary size register) to the image I / F unit 117, pixels that have not become an integral multiple of the boundary size are discarded. That is, image data that is an integral multiple of the boundary size after pixel truncation is transferred to the image I / F unit 117.

As described above, when the scaling processing unit 207 temporarily stores the image data after scaling processing in the line buffer and transfers the image data to the image I / F unit 117, the main scanning size of the image data is set. By adjusting the number of pixels to be an integral multiple of the boundary size for the image I / F unit 117, only image data up to the main scanning size that is an integral multiple of the boundary size for the image I / F unit 117 is reliably transferred. can do.

[Seventh embodiment]
Next, a seventh embodiment will be described.
The seventh embodiment is obtained by adding the following configuration to any one of the first to sixth embodiments.

  In the scanner image processing unit 115a, the 436 pixels that were cut off by the transfer of the previous page divided into rectangles must be transferred to the next page, so that the size after the scaling process was actually transferred to the subsequent module. Information on how many pixels 3,584 pixels correspond to the image size before scaling processing is required. For this purpose, the scaling processing unit 207 must count the pixels before the scaling process and hold the count information as the pre-scaling pixel position information until the next page is transferred.

In the example of FIG. 8, it is necessary to hold count information of 5,349 (3,584 / 0.67) pixels as pre-magnification pixel position information. In addition, since the virtual pixel is generated in the scaling process, it does not necessarily coincide with the pixel position before the scaling process. In the example of FIG. 8, this corresponds to a fraction of 2/8. Therefore, this fraction information is also held up to the next page and used in the scaling process of the next page.
If the image transfer of the next page is performed in consideration of the truncated pixels, the pixels to be originally read from the external memory 118 are to be changed from the 6,000-304 = 5,696th pixels to the 5,349-304. = 5,045th pixel is changed.

  In this way, the image of the next page that has been divided into rectangles in consideration of the number of pixels that the scanner image processing unit 115a has cut off from the image data of the previous page that has been divided into rectangles and transferred to the controller 120 via the scaling processing unit 207. By transferring the image data of the pixel back to the controller 120 via the scaling processing unit 207 from the image data traced back to the pixel, between the rectangular areas when transferring the image data of the rectangular area (rectangular divided pages) It is possible to more reliably prevent deterioration in image quality at the joint portion.

[Eighth embodiment]
Next, an eighth embodiment will be described.
In the scanner image processing unit 115a of FIG. 3, if the main scanning size and the scaling factor of the image data before scaling processing by the scaling processing unit 207 are known in advance, the main scanning size of the image data after scaling processing is determined by software. Therefore, the main scan size (main scan length) of the image data of the page to be divided into rectangles can be calculated and set in advance so that the main scan size matches the boundary size. Thereby, the main scanning size (image size width) of the image data to be retransferred can be fixed.

  As described above, the main image data of the page that is divided into rectangles in advance by the scanner image processing unit 115a so that the size of the image data in the main scanning direction after the scaling processing by the scaling processing unit 207 matches the predetermined boundary size. By calculating and setting the size in the scanning direction, the image data does not fit the boundary size, so that it is not necessary to re-transfer unnecessary image data, and the transfer efficiency is improved. That is, it is possible to efficiently prevent the image quality deterioration at low cost when the image data of the divided pages is subjected to the scaling process and transferred to the controller 120.

[Ninth embodiment]
Next, a ninth embodiment will be described.
FIG. 9 is an explanatory diagram showing an example of the configuration and data flow of the scanner image processing unit 115a for explaining the adjustment of the line gate width.

  When image transfer from the reading unit 112 is started in the scanner image processing unit 115a in FIG. 3, the external memory I / F unit 204 receives image data from the input I / F unit 201, and the first image data to the external memory 118 is received. When the image transfer for one line is completed, the main scanning size can be detected (see FIG. 10A). Alternatively, the main scanning size is set in the register in advance by software (before actually starting image processing).

  After that, as shown in FIG. 9, a dummy line gate signal equivalent to the line gate signal is automatically issued from the external memory I / F unit 204 to the scaling processing unit 207 in the scanner image processing unit 115a, and the change is made. A dedicated calculation circuit (not shown) determines the width of the line gate signal actually used (during actual image transfer) (hereinafter also referred to as “line gate width”) so that the main scanning size after the doubling processing matches the boundary size. Calculate it. That is, before the image data of the page to be divided into rectangles is transferred to the scaling unit 207 in advance, the main scan size of the image data is automatically adjusted using the dummy line gate signal. The information of the line gate width is required for the number of rectangles divided in the main scanning direction.

At the time of actual image transfer, unnecessary image data is read out from the external memory 118 by reading out image data (image data divided into rectangles) for the image size to which the margins before and after are added based on the predetermined line gate width. Prevent re-transfer of image data.
When a dummy line gate signal for determining the line gate width is issued, that is, when the line gate width is determined, access to the external memory 118 is prohibited, thereby preventing the image data from the external memory 118 from being accessed. Reading and image transfer to the controller 120 are not performed. The same applies to the tenth embodiment described later.

As described above, the scanner image processing unit 115a automatically adjusts the main scan size of the image data using the dummy line gate signal before transferring the image data of the divided pages to the scaling processing unit 207 ( (The dedicated calculation circuit calculates the line gate width so that the main scan size of the image data after scaling processing matches the boundary size), so that unnecessary image data can be restored without calculating the line gate width by software. There is no transfer and the transfer efficiency is increased. That is, it is possible to efficiently prevent the image quality deterioration at low cost when the image data of the divided pages is subjected to the scaling process and transferred to the controller 120.
Further, when issuing a dummy line gate signal (determining the line gate width), prohibiting access to the external memory 118 prevents unnecessary image data transfer, which adversely affects image transfer efficiency. You do n’t have to.

[Tenth embodiment]
Next, a tenth embodiment will be described.
When image transfer from the reading unit 112 is started in the scanner image processing unit 115a in FIG. 3, the external memory I / F unit 204 receives image data from the input I / F unit 201, and the first image data to the external memory 118 is received. When the image transfer for one line is completed, the main scanning size can be detected (see FIG. 10A). Alternatively, the main scan size is set in advance in the register by software. Thereafter, as shown in FIG. 9, a dummy line gate signal is automatically issued from the external memory I / F unit 204 to the scaling unit 207 in the scanner image processing unit 115a.

  The scaling processing unit 207 performs actual processing based on the dummy line gate signal so that the main scanning size of the image data after the scaling processing (image data to be transferred by the image I / F unit 117) matches the boundary size. The main scanning size of the image data of the page to be divided into rectangles is calculated by causing the internal scaling control circuit (consisting of the above-described counters, etc.) to perform the same operation as the scaling process, and the line is based on the calculation result. The gate width information and the fraction information by the scaling process at that time are held. Further, the external memory I / F unit 204 is notified of information on the line gate width when the dummy line gate signal is negated. The fraction information is used for scaling processing when the next dummy line gate signal is issued.

FIG. 10 is a timing chart showing an example of an outline of operation when a dummy line gate signal is used in the scanner image processing unit 115a, and shows an example in which four rectangular divisions are performed on the image data in the main scanning direction.
In the scanner image processing unit 115a, before the external memory I / F unit 204 actually starts reading out the image data of the page divided into rectangles from the external memory 118, the scaling processing unit 207 in FIG. A dummy line gate signal as shown in FIG.

The scaling unit 207 performs the same calculation as in the actual scaling process based on the dummy line gate signal, so that the line gate widths b1, b2, b3 that are actually used in advance as described above. b4 and fractions B1, B2, B3, B4 are determined.
The external memory I / F unit 204 reads image data from the external memory 118 using the line gate widths b1, b2, b3, and b4.
FIG. 11 is a timing chart for explaining an example of a method for determining a line gate width and a fraction to be actually used when a dummy line gate signal is used in the scanner image processing unit 115a.

When the dummy line gate signal is asserted, the scaling unit 207 counts the assert period. In addition, the number of pixels after scaling processing is also counted, and the number of assertion periods of the dummy line gate signal when the number of pixels after scaling processing is an integral multiple of the boundary size of the image I / F unit 117 (In FIG. 11, it is assumed that the boundary size of the image I / F unit 117 is “128”. In this case, the values of the input line gate counter are a and b, and the main scanning is performed. The value of the fraction of coordinates is A and B).
This is repeated until the dummy line gate signal is negated, and the last information becomes the information of the actually used line gate width and fraction. The fraction of the main scanning coordinate is used when the dummy line gate signal for the next rectangular area is asserted.

  As described above, the size of the image data in the main scanning direction after the scaling processing by the scaling processing unit 207 before the scanner image processing unit 115a transfers the image data of the divided pages to the scaling processing unit 207. The main scan of the image data of the page to be divided into rectangles by using the dummy line gate signal so that the size is matched with the boundary size and causing the scaling control circuit of the scaling processing unit 207 to perform the same operation as in the actual scaling process. By calculating the size in the direction and determining the line gate width based on the calculation result, it is possible to obtain substantially the same effect as in the ninth embodiment. In this case, when the line gate width is calculated, a scaling control circuit that is actually used during scaling processing is used, so there is no need to add a dedicated calculation circuit.

  The embodiment in which the present invention is applied to the MFP has been described above. However, the present invention is not limited to this, and other image forming apparatuses such as a digital copying machine, a facsimile apparatus, and a printer, as well as an image reading apparatus (scanner apparatus, etc.). ) And various image processing apparatuses such as a PC.

  As is apparent from the above description, according to the present invention, it is possible to prevent image quality degradation at a low cost when the image data of a rectangularly divided page is subjected to scaling processing and transferred to the outside. Therefore, an image processing apparatus with high image quality and low cost can be provided.

1 is a block diagram illustrating a hardware configuration example of an MFP according to an embodiment of the present invention. It is a block diagram which shows the specific structural example of the engine part 110 of FIG. It is explanatory drawing which shows an example of a structure and data flow of the scanner image processing part 115a of FIG. It is explanatory drawing which shows an example of the margin with each image size after a division | segmentation in the case of performing a rectangular division process with respect to the image data on the external memory 118 of FIG.

FIG. 5 is an explanatory diagram illustrating an example of a relationship between a divided rectangular area illustrated in FIG. 4 and each gate signal corresponding to an image effective area for each module. FIG. 4 is a diagram for explaining a scaling process of 150% (enlargement) and 67% (reduction) in the main scanning direction performed on image data by the scaling process unit 207 of FIG. 3. The number of pixels necessary for the filter processing unit 206 in FIG. 3, the number of input pixels to the scaling processing unit 207, the number of pixels after scaling by the scaling processing unit 207, and the output from the image I / F unit 117 to the controller 120 It is a conceptual diagram for demonstrating an example of the image size performed. FIG. 4 is a diagram for explaining a method of truncating the remaining pixels that have not become an integral multiple of a predetermined boundary size for the image I / F unit 117 of FIG. 3 and a method of adding the discarded pixels on the next page. .

It is explanatory drawing which shows an example of a structure and data flow of the scanner image processing part 115a of FIG. 3 for demonstrating adjustment of a line gate width. FIG. 10 is a timing diagram illustrating an outline example of an operation when a dummy line gate signal is used in the scanner image processing unit 115a illustrated in FIG. 9. FIG. 10 is a timing chart for explaining an example of a method of determining a line gate width and a fraction to be actually used when a dummy line gate signal is used in the scanner image processing unit 115a shown in FIG.

100: MFP 110: Engine unit 111: CPU 112: Reading unit 113: Writing unit 114: ASIC-E 115: Image processing unit 115a: Scanner image processing unit 115b: Printer image processing unit 117: Image I / F unit 118: External memory 120: Controller 121: Operation unit 122: HDD 123: CPU 124: ASIC-C
125: Rotator 126: Editor 127: MEM-C 128: NB
129: MEM-P 130: ASIC 131, 132: OPTION
133: SB 134: ROM 201: Input I / F unit 202, 203: FIFO 204: External memory I / F unit 205: Preprocessing unit 206: Filter processing unit 207: Scaling processing unit

Claims (6)

Rectangle dividing means for dividing image data into a plurality of pages, scaling processing means for performing scaling processing in the main scanning direction on the image data of the pages divided into rectangles by the rectangle dividing means, and the scaling processing An image processing apparatus having image transfer means for transferring image data scaled by the means to the outside ,
When the image data of the rectangle divided page is transferred to the outside by the image transfer means via said scaling means by said block dividing means, in the main scanning direction of the image data from the magnification processing unit When the size does not become an integral multiple of the boundary size , which is the set value of the number of pixels according to the image transfer conditions in the image transfer means , the image data up to the maximum main scanning length that is an integral multiple of the boundary size is transferred. The remaining pixels are discarded , and at least the number of pixels before scaling used for image transfer up to that time is held until the image data transfer period for the next page, and is held when transferring the image data for the next page. and that on the basis of the number of pixels before scaling, to transfer the image data back number of pixels truncated said the image data of the next page to the outside via said scaling means control The image processing apparatus characterized in that a control means for performing. Oite the image processing apparatus according to claim 1,
An image processing apparatus, wherein the boundary size is a set value of the number of pixels calculated from a bus width of an image transfer bus . Oite the image processing apparatus according to claim 1,
The image processing apparatus according to claim 1, wherein the boundary size is a set value of the number of pixels calculated from a burst length of burst transfer . Oite the image processing apparatus according to any one of claims 1 to 3,
The control means counts the number of pixels in the main scanning direction of the image data of the page divided into rectangles by the rectangle dividing means, which is image data before the magnification processing input to the magnification processing means. A scanning counter, a post-magnification main scanning counter that counts the number of pixels in the main scanning direction of image data transferred to the outside after scaling processing in the main scanning direction by the scaling processing unit, and a boundary that holds the boundary size When it is detected that the value of the size register and the post-magnification main scan counter are the maximum main scan length value that is an integral multiple of the boundary size, the post-magnification main scan counter value and the change holding the multiplied value before the main scan counter, held until the end of the transfer to the outside of the image data of the rectangle divided next page by the values the block dividing means Kauntare And a static, when the transfer of image data for the next page, the image processing apparatus, characterized in that the counter register to determine the image data to be transferred from the value held. Oite the image processing apparatus according to claim 4,
The image transfer means includes a part of the control means, and the post-magnification main scan counter value when the post-magnification main scan counter value is a maximum main scan length value that is an integral multiple of the boundary size. A scan counter value is received, and among the image data received from the scaling processing means, image data for the size in the main scanning direction up to the scaled main scan counter value is transferred to the outside. Image processing device. Oite the image processing apparatus according to any one of claims 1 to 4,
The control means has storage means for storing the image data after the scaling process by the scaling processing means, and when transferring the image data stored in the storage means to the image transfer means, the image data the image processing apparatus characterized by transferring to the image transfer means to the maximum main scanning length an integral multiple of the boundary size.

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