JP4316476B2 - Image processing apparatus and image forming apparatus - Google Patents

Description

  The present invention relates to an image processing apparatus that performs image processing on a target pixel using pixels in the vicinity of the target pixel to be processed, and an image forming apparatus including the image processing apparatus.

  Neighboring image processing that performs image processing of a target pixel using pixels in the vicinity of the target pixel to be processed is a commonly used image processing method. Various image input devices such as cameras and scanners, and image processing It is used in many devices such as image processing devices that perform image processing, image output devices such as printers and displays.

  In the near image processing, since a distant pixel is not referred to for the processing of the target pixel, the image can be divided by a plurality of CPUs (central processing units). Since it does not depend on the unit, each CPU can perform processing without cooperating with other CPUs.

  Further, when image data is appropriately divided (for example, divided into a plurality of square areas of the same size and distributed to each CPU), and processing is performed, it is often used for free CPUs or CPUs with high processing speed. By processing the divided data, the processing of the entire image data can be completed earlier.

  FIG. 4 is a diagram illustrating a divided image of image data. The whole figure represents one image data, and each subdivided area represents a pixel. When the pixel 31 is the target pixel, the eight pixels 32 in the surrounding shaded area are, for example, neighboring pixels used for image processing of the pixel 31. Each area delimited by the thick line is divided image data (divided data), and is distributed to each CPU for each unit and subjected to image processing in parallel. At this time, in order to perform image processing for the pixel at the outermost edge of the divided data (when eight pixels adjacent to the target pixel are used as neighboring pixels), one pixel outside (that is, one outside of the thick line) Since it is necessary to use pixels, it is also necessary to give each CPU a pixel row that is one outside of the divided area. Therefore, in practice, the pixels in the shaded area around the thick line are captured twice or four times for each divided area.

  For example, when eight pixels adjacent to the target pixel are used as neighboring pixels, the three columns of divided data shown in the hatched area 33 are data stored in the internal memory of the CPU. At this time, the pixels in the middle column are processed. After the processing of the pixels in the middle column is finished, the pixels in the upper column are discarded, the pixels in the next (lower) column of the hatched area 33 are taken into the internal memory, and the next (lower) in the middle column is taken. Image processing of the pixels in the column (b) is performed.

  However, when image processing is performed by dividing an image into each CPU as described above, data near the boundary of each division unit must be duplicated in each CPU. For this reason, since the data of the overlapping portion is fetched from the storage means such as the external memory into the internal memory of the CPU a plurality of times, there is a problem that it takes extra time.

  SUMMARY An advantage of some aspects of the invention is that it provides an image processing apparatus capable of performing image processing faster and an image forming apparatus including the image processing apparatus.

The image processing apparatus according to claim 1 is an image processing apparatus that determines a value of a target pixel using a value of a target pixel to be subjected to image processing and a value of a pixel in the vicinity thereof.
A plurality of image processing means each having an internal memory;
Dividing means for dividing the image data so that the capacity of each internal memory and the total size of pixels necessary for image processing for one line in the main scanning direction of each divided image data substantially match;
Each of the image data divided by the dividing means is distributed to the image processing means having a capacity of an internal memory in which the total size of pixels necessary for image processing for one line in the main scanning direction is substantially the same. Control means for performing processing;
Combining each image data processed by each image processing means into one image data ,
The dividing means divides the image data so that the length of the divided image data processed by the same image processing means becomes longer in the sub-scanning direction .

  According to this configuration, each image data divided by the dividing unit is controlled by the image processing unit having a capacity of an internal memory in which the total size of pixels necessary for image processing for one line in the main scanning direction substantially matches. The image processing is performed by being distributed by each of the means, and the processed image data is combined into one image data by the combining means.

An image processing apparatus according to a second aspect is the image processing apparatus according to the first aspect , further comprising storage means for storing processing speeds of the plurality of image processing means, wherein the dividing means is the storage means. The image data is divided on the basis of the processing speed of each image processing means stored in the image processing so that the image processing is completed at a time close to each image processing means.

An image processing apparatus according to claim 3 is the image processing apparatus according to claim 1 or 2 , wherein the dividing unit divides only the image processing unit that is not being processed among the plurality of image processing units. The control means distributes the image data divided by the dividing means only to the image processing means not being processed.

An image processing apparatus according to a fourth aspect is the image processing apparatus according to any one of the first to third aspects, wherein the dividing unit is a greatest common divisor of a capacity of an internal memory included in each of the plurality of image processing units. Subdivision means for dividing the image data so that the total size of pixels necessary for image processing for one line in the main scanning direction of each divided image data substantially matches, the capacity of each internal memory, The image processing apparatus includes a combining unit that combines the image data divided by the subdivision unit so that the total size of pixels necessary for image processing for one line in the main scanning direction of each divided image data is substantially the same.

  According to this configuration, the image data is divided into fine unit areas by the subdivision unit, and the image data is combined by the combining unit, whereby the original image data is divided so as to correspond to each image processing unit. The

An image forming apparatus according to a fifth aspect includes the image processing apparatus according to any one of the first to fourth aspects. According to this configuration, it is possible to provide an image forming apparatus that exhibits any one of claims 1 to 4 .

  According to the first aspect of the invention, by dividing the image data in the main scanning direction, it is possible to reduce the area that is redundantly read with other image processing means and Since the access time for the image data can be reduced, it is possible to provide an image processing apparatus that can perform image processing faster.

Furthermore, according to the invention described in claim 1 , by dividing the image data in the sub-scanning direction, it is possible to reduce the area that is redundantly read between the same or other image processing means, Since the access time for the image data of the overlapping portion can be reduced, it is possible to provide an image processing apparatus that can perform image processing faster.

According to the second aspect of the present invention, since the image processing for the image data divided by each image processing means is completed at a near time (that is, almost at the same time), a vacant image processing means (the processing is finished early). Therefore, it is possible to provide an image processing apparatus that can use resources (image processing means) more effectively and perform image processing faster without creating image processing means).

According to the third aspect of the present invention, since image processing is performed using only image processing means that is not being processed (free), an image processing apparatus that can perform image processing easily and more quickly is provided. be able to.

According to the fourth aspect of the present invention, the image data can be easily divided so as to correspond to each image processing means.

According to the fifth aspect of the present invention, it is possible to provide an image forming apparatus having the effect of any one of the first to fourth aspects.

  Embodiments according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram illustrating a functional configuration of a multifunction peripheral that is an example of an image forming apparatus according to an embodiment of the present disclosure. The multifunction machine 2 is a digital copying machine having a plurality of functions such as a copying function, a printing function, and a facsimile function. The multifunction device 2 includes an image data acquisition unit 21, an image processing unit 1, and an image output unit 22.

  The image data acquisition unit 21 acquires image data by acquiring image data through a network or a telephone line, or by reading an image from a document with an image reading unit (not shown). The image output unit 22 prints the image data processed by the image processing unit 1 on a recording sheet and outputs it, or outputs it to another image forming apparatus or information processing apparatus (for example, a PC (Personal Computer) via a network or a telephone line. )) Etc. and output.

  The image processing unit 1 performs image processing on the image data acquired by the image data acquisition unit 21. Here, the image processing is processing such as removing noise of an image or smoothing lines such as characters. The image processing unit 1 includes a data division unit 12, a processing control unit 13, an image composition unit 14, processing unit units 15, 16, 17, a processing unit unit state acquisition unit 18, and a processing speed storage unit 19. The image processing unit 1 includes a plurality of processing unit units (three in this embodiment), divides the image data, and distributes the image data to the plurality of processing unit units 15, 16, and 17 for image processing. I do.

  The processing unit units 15, 16, and 17 are processing devices that perform various types of processing including image processing (for example, facsimile transmission / reception processing), and are, for example, a CPU (Central Processing Unit) or an ASIC (Application Specific Integrated Circuit). Each of the processing units 15, 16, and 17 may be dedicated for image processing, or may be a general-purpose device that performs other processing in addition to image processing. In this embodiment, the processing unit unit 15 is dedicated to image processing, and the processing unit units 16 and 17 are general-purpose units. In addition, the processing unit sections 15, 16, and 17 generally include internal memories 151, 161, and 171 having different sizes. The processing units 15, 16, and 17 can access the internal memories 151, 161, and 171 included in the processing units 15, 16, and 171 at higher speed with respect to an external storage device (for example, an external memory). Therefore, when processing can be completed using only data stored in the internal memory, processing can be performed at higher speed. In the present embodiment, the internal memories 161 and 171 of the processing unit units 16 and 17 have a capacity twice that of the internal memory 151 of the processing unit unit 15. In addition, the processing unit sections 15, 16, and 17 generally have different processing speeds. In the present embodiment, it is assumed that the processing unit units 15 and 16 have a processing speed twice that of the processing unit unit 17.

  The processing speed storage unit 19 stores the processing speed (for example, the number of operation clocks of the CPU) of each processing unit unit 15, 16, 17 included in the image processing unit 1. The processing unit unit state acquisition unit 18 acquires a state as to whether or not each processing unit unit 15, 16, 17 is processing.

  The data dividing unit 12 acquires the status of each of the processing unit units 15, 16, and 17 from the processing unit unit status acquisition unit 18, and when the image processing is distributed to the vacant (not processing) processing unit units, The image data is divided so that the image processing is completed at the same time. The data dividing unit 12 includes a fine dividing unit 121 and a combining unit 122. The subdivision unit 121 acquires the states of the processing unit units 15, 16, and 17 from the processing unit unit state acquisition unit 18, and sets the vacant (not processing) processing unit units as processing unit units that perform the image processing. select. The subdivision unit 121 divides the maximum common divisor (for example, the size of the internal memory of the processing unit unit 15) by 3 lines into the size of each internal memory of the selected processing unit unit (for example, the processing unit units 15, 16, and 17). (Here, a line is a line in which one pixel is connected in the main scanning direction in the sub-scanning direction.) The number of pixels (10 in this embodiment) obtained by subtracting two pixels from the storable line length (number of pixels). The main scanning direction is divided by pixel. Then, the sub-scanning direction is divided by a predetermined arbitrary number of pixels (15 pixels in the present embodiment).

  The combining unit 122 reads the processing speeds of the selected processing unit units 15, 16 and 17 from the processing speed storage unit 19. Then, the combining unit 122 sets each divided area divided by the subdividing unit 121 to a line length that can store three lines in each internal memory size of the selected processing unit units 15, 16, and 17. They are combined in the main scanning direction, and are further combined in the sub-scanning direction based on the processing speed so that the end times of the image processing in the processing unit units 15, 16, and 17 are almost the same time. That is, the combining unit 122 (when the processing speed of the processing unit units 15 and 16 is twice that of the processing unit unit 17) is divided into other subdivided regions in the main scanning direction as divided regions to be allocated to the processing unit unit 15. Are divided into two subdivision areas in the main scanning direction, and the division areas corresponding to the processing unit sections 15 and 16 are substantially the same. The entire area is divided so that the divided area corresponding to the processing unit section 17 is approximately half of the area corresponding to the processing unit sections 15 and 16 in terms of size. At this time, the combining unit 122 makes the regions of the image data processed by the same processing unit unit as continuous as possible in the sub-scanning direction. As long as the image data to be processed by the same processing unit is connected vertically, it is not necessary to read the data redundantly in the vertical direction, so that the image processing can be performed faster.

  2A and 2B are diagrams illustrating an image division method. FIG. 2A shows a first stage of division (that is, a division result by the fine division unit 121), and FIG. 2B shows a final division result (that is, a division result). , An example of a result of combining by the combining unit 122). Each figure shown in FIG. 2 represents the entire image, and each area obtained by subdividing the image represents pixels constituting the image. The divided data in the present embodiment shown in FIG. 2B has less shaded portions (that is, overlapping portions) than the conventional divided data shown in FIG. 4, so that image processing can be performed faster.

  Returning to FIG. 1, the processing control unit 13 sequentially applies the data divided by the data dividing unit 12 to the processing unit units 15, 16, and 17 (one line at a time) to perform processing. The image synthesizing unit 14 sequentially receives the image data processed by the processing unit units 15, 16, and 17 from the processing unit units, and synthesizes them to form one image. That is, the image is synthesized so that each processed pixel is at the same position as the original. The image composition unit 14 receives information on the position of the processed image data (within the image before the division) from the data division unit 12.

Next, the flow of image processing in the image forming apparatus 2 will be described. Figure 3 is a flow chart showing the flow of image processing in the image forming apparatus 2.

  In step S <b> 1, the image data acquisition unit 21 acquires image data and transmits it to the data division unit 12. In step S <b> 2, the data dividing unit 12 acquires the free state of each processing unit unit 15, 16, 17 from the processing unit unit state acquisition unit 18. In step S3, the data dividing unit 12 selects a free processing unit unit as a processing unit unit that performs the image processing. The data dividing unit 12 divides the image data acquired from the image data acquiring unit 21 so as to correspond to the selected processing unit units.

  In step S4, the processing control unit 13 performs the next one line of each image data corresponding to each processing unit unit 15, 16, and 17 divided by the data dividing unit 12 (first time is for three lines), Transmit to the corresponding processing unit. In step S5, each processing unit 15, 16, 17 performs image processing for one line. In step S6, the image synthesizing unit 14 receives image data for one line for which processing has been completed from the processing unit units 15, 16, and 17, and writes the image data in a storage position corresponding to the image data (that is, synthesizes the images). .) In step S7, the process control unit 13 checks whether there is still image data (line) for which image processing has not been performed. If there is still image data (YES in step S7), the process control unit 13 returns to step S4. If there is no more image data that has not undergone image processing in step S7 (NO in step S7), the process proceeds to step S8. In step S8, the image composition unit 14 transmits the synthesized image to the image output unit 22, and the image output unit 22 outputs this image (in the designated method).

  As described above, in the present embodiment, the division position of the image data in the main scanning direction is determined based on the capacity of the internal memory unit included in the usable processing unit unit, and further, the division unit to be processed by the same processing unit unit. Since it was not divided as much as possible in the sub-scanning direction, by dividing the image and processing it, there are fewer areas that overlap into a plurality of divisions, and it is not necessary to read this part redundantly. The processing speed can be further increased.

  In addition, this invention is not limited to the thing of the said embodiment, The aspect described below can be employ | adopted. In the present embodiment, eight pixels adjacent in the vertical, horizontal, and diagonal directions of the target pixel are used as the neighboring pixels in the pixel image processing, but the neighboring pixels are not necessarily the eight pixels. It may be a pixel further outside these eight pixels or a pixel at a distant location. Since the line read into the internal memory unit of the processing unit unit is a line including the target pixel and the neighboring pixel, the line and line read into the internal memory unit of the processing unit unit according to which pixel is used as the neighboring pixel. The number is different.

  In the above embodiment, the subdivision is performed once by the subdivision unit, and then the subdivision regions are combined by the combining unit to create the final subregion. However, subdivision is not necessarily performed. That is, the division may be directly performed on the final divided area without performing division into areas having the same shape and size smaller than the final divided area.

  The image dividing method according to the present invention need not always be performed, and may be performed only when processing needs to be performed quickly. For example, the image dividing method according to the present invention may be used when the copy function is used, and the image dividing method according to the present invention may not be used when the print function is used.

1 is a block diagram illustrating a functional configuration of an image forming apparatus according to an embodiment of the present invention. 2A and 2B are diagrams illustrating an example of image division according to an embodiment of the present invention, in which FIG. 3A is a diagram illustrating a first stage of image division, and FIG. 6 is a flowchart illustrating a processing flow of the image forming apparatus according to the embodiment of the present invention. It is a figure which shows the example of an image division in the conventional image processing apparatus.

1 Image processing unit (image processing device)
12 Data division unit 121 Subdivision unit (subdivision means)
122 coupling part (coupling means)
13 processing control unit 14 image composition unit 15, 16, 17 processing unit unit (image processing means)
19 Processing speed storage unit (storage means)
2 MFP (image forming device)
31 pixel of interest 32 neighboring pixels (neighboring pixels)

Claims (5)

In an image processing apparatus that determines a value of a target pixel using a value of a target pixel to be subjected to image processing and a value of a pixel in the vicinity thereof,
A plurality of image processing means each having an internal memory;
Dividing means for dividing the image data so that the capacity of each internal memory and the total size of pixels necessary for image processing for one line in the main scanning direction of each divided image data substantially match;
Each of the image data divided by the dividing means is distributed to the image processing means having a capacity of an internal memory in which the total size of pixels necessary for image processing for one line in the main scanning direction is substantially the same. Control means for performing processing;
Combining each image data processed by each image processing means into one image data ,
The division unit is an image processing apparatus that divides image data so that the length in the sub-scanning direction of the divided image data processed by the same image processing unit becomes longer . A storage means for storing the processing speed of each of the plurality of image processing means;
Said dividing means, based on the processing speed of the image processing unit stored in said storage means, according to claim 1 in which the image processing is to divide the image data so as to terminate at a time close in each image processing unit Image processing device. The dividing unit divides only the image processing unit not being processed among the plurality of image processing units,
Said control means, the image processing apparatus according to the image data divided by said dividing means to claim 1 or 2 is dispersed only in the image processing unit not being the process. The dividing unit has a maximum common divisor of the capacity of the internal memory included in each of the plurality of image processing units and a total size of pixels necessary for image processing for one line in the main scanning direction of each divided image data. Subdivision means for dividing the image data to match,
The image data divided by the subdivision means is arranged so that the capacity of each internal memory and the total size of pixels necessary for image processing for one line in the main scanning direction of each divided image data are substantially the same. the image processing apparatus according to any one of claims 1 to 3, and a coupling means for coupling to. An image forming apparatus including an image processing apparatus according to any one of claims 1-4.

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