JP2013164557A - Image forming control device, image forming control method, and image forming control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transfer reference data to an inspection apparatus with high efficiency, in inspecting an image by comparing an image formed by reading a result of image forming output and a master image.SOLUTION: In an image inspection system for inspecting an image, an engine controller 2 for controlling a print engine 3 includes: a data acquiring part 201 that acquires bitmap data; an engine control part 202 that causes the print engine 3 to execute image forming output on the basis of the bitmap data; and a master image processing part 203 that transmits information generated for an inspection apparatus 4 for inspecting images, on the basis of the bitmap data for the master image to be referred in the inspection. In a solid area of a predetermined range or larger in the bitmap data, information for specifying the solid area is generated instead of the information on the pixel of the range.

Description

  The present invention relates to an image inspection apparatus and an image inspection method, and more particularly to a method for transferring an image referred to when inspecting an image to the inspection apparatus.

  Conventionally, inspection of printed matter has been performed manually, but in recent years, an apparatus for performing inspection has been used as post-processing of offset printing. In such an inspection apparatus, a master image serving as a reference is generated by manually selecting and reading a non-defective product from the read image of the printed matter, and a corresponding portion of the master image and the read image of the printed matter to be inspected. And the defect of the printed matter is discriminated by the degree of these differences.

  However, plateless printing devices such as electrophotography, which have become popular in recent years, are good at printing a small number of parts, and there are many cases where the content of printing on each page differs, such as variable printing, and a master image is generated from printed matter like an offset printer. In comparison, it is inefficient. In order to cope with this problem, it is conceivable to generate a master image from print data. Thereby, it is possible to efficiently cope with variable printing.

  As described above, in order to generate a master image from print data and perform comparison inspection of the image, at least one of the print data and the master image generated based on the print data in the inspection apparatus that performs image comparison inspection (Hereinafter referred to as “reference data”). If the variable printing described above is assumed, the contents of the images on each page are different, and therefore the reference data must be transferred on each page.

  On the other hand, as a technique for improving the transfer efficiency of image information, a method has been proposed in which blank area information corresponding to a blank area where information is not printed is transferred to an engine unit from other than the storage means (for example, a patent). Reference 1).

  In order to improve the productivity of printing indicated by PPM (Page Per Minute) or the like, the reference data is transferred to the inspection device so that the plotter indicated by PPM corresponds to the speed at which image forming output is executed, and every page. It is necessary to complete the inspection. However, since the print data of a printed matter requiring high quality such as commercial printing is high definition, the amount of data is large, and it takes time to transfer the data.

  The method disclosed in Patent Document 1 determines whether or not each predetermined band unit is blank, and if there is even a small print range in the band, the image information of that band is as usual. Therefore, it is insufficient for reducing the transfer amount of image data.

  Further, the method disclosed in Patent Document 1 is based on the premise of image transfer to an engine that executes image formation output, and aims to reduce blank data from the actual print end position to the end of the print area. Therefore, the gist of the present invention is different from that of the present invention, which aims to transfer a master image or print data for generating a master image to an inspection apparatus.

  The present invention has been made in view of the above circumstances, and improves the transfer efficiency of reference data to an inspection apparatus in an image inspection by comparing an image obtained by reading an output result of image formation output with a master image. For the purpose.

  In order to solve the above-described problem, an aspect of the present invention provides an image forming apparatus that controls an image forming apparatus in an image inspection system that inspects a read image obtained by reading an image formed and output on a paper surface by an image forming apparatus. A control device, a pixel information acquisition unit for acquiring pixel information which is information on an image to be imaged and output and which is information of each pixel constituting an image to be imaged and output, and based on the pixel information Information generated based on the pixel information for an inspection image that is referred to in an inspection with respect to an output execution control unit that causes the image forming apparatus to perform image formation output and an inspection apparatus that inspects the read image The inspection image processing unit transmits information on pixels in the range of the pixel information with respect to a plain range greater than or equal to a predetermined range. Instead and generates the information for specifying the range of plain and.

  According to another aspect of the present invention, there is provided an image formation control method for controlling the image forming apparatus in an image inspection system that inspects a read image obtained by reading an image formed and output on a paper surface by the image forming apparatus. , Obtaining pixel information that is information on an image to be image-formed and that is information on each pixel that constitutes an image to be image-formed, and executes image-formation output to the image-forming apparatus based on the pixel information And transmitting information generated on the basis of the pixel information for an inspection image to be referred to in the inspection to the inspection apparatus that inspects the read image. For the plain range, information for specifying the plain range is generated instead of the pixel information of the range.

  Still another embodiment of the present invention is an image formation control program for controlling an image forming apparatus in an image inspection system that inspects a read image obtained by reading an image formed and output on a paper surface by an image forming apparatus. Acquiring pixel information which is information on an image to be image-formed and which is information on each pixel constituting the image to be imaged and output, and forming an image on the image forming apparatus based on the pixel information. A step of executing an output; a step of transmitting information generated based on the pixel information for an inspection image referred to in an inspection to an inspection device that inspects the read image; and When generating the information to be transmitted, the plain area of the pixel information that is equal to or larger than the predetermined range is replaced with the plain area range. Characterized in that to be executed by the information processing apparatus and generating information indicating a.

  According to the present invention, it is possible to improve the transfer efficiency of reference data to an inspection apparatus in an image inspection by comparing an image obtained by reading an output result of image formation output with a master image.

1 is a diagram illustrating a configuration of an image forming system including an inspection apparatus according to an embodiment of the present invention. It is a block diagram which shows the hardware constitutions of the test | inspection apparatus which concerns on embodiment of this invention. It is a block diagram which shows the function structure of the engine controller which concerns on embodiment of this invention, a print engine, and an inspection apparatus. It is a figure which shows the mechanical structure of the printing process part which concerns on embodiment of this invention. It is a block diagram which shows the function structure of the master image process part which concerns on embodiment of this invention. It is a figure which shows the example of the bitmap data which concerns on embodiment of this invention. It is a flowchart which shows operation | movement of the engine controller which concerns on embodiment of this invention. It is a flowchart which shows the operation | movement of the page head process which concerns on embodiment of this invention. It is a flowchart which shows the operation | movement of the page termination process which concerns on embodiment of this invention. It is a figure which shows the example of the original master image which concerns on embodiment of this invention. It is a figure which shows the production | generation main body of the analysis result information which concerns on other embodiment of this invention. It is a figure which shows the production | generation main body of the analysis result information which concerns on other embodiment of this invention. It is a figure which shows the example of the original master image which concerns on other embodiment of this invention. It is a figure which shows the example of the bitmap data which concerns on other embodiment of this invention. It is a figure which shows the example of the bitmap data which concerns on other embodiment of this invention. It is a flowchart which shows operation | movement of the engine controller which concerns on other embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, an image forming system including an inspection device that inspects an output result will be described with a feature of a transfer mode of print data that is a source of an inspection image referred to when the inspection device inspects an output result.

  FIG. 1 is a diagram illustrating an overall configuration of an image forming system according to the present embodiment. As shown in FIG. 1, the image forming system according to the present embodiment includes a DFE (Digital Front End) 1, an engine controller 2, a print engine 3, and an inspection device 4. The DFE 1 generates image data to be printed out based on the received print job, that is, bitmap data that is an output target image, and outputs the generated bitmap data to the engine controller 2.

  The engine controller 2 controls the print engine 3 based on the bitmap data received from the DFE 1 to execute image formation output. In addition, the controller 2 according to the present embodiment has information (hereinafter, referred to as a master image) that is information of an image for inspection to be referred to when the inspection apparatus 4 inspects the result of image formation output by the print engine 3. The “original master image” is generated based on the bitmap data and transmitted to the inspection apparatus 4. The transmission mode of information to the inspection device 4 is a characteristic configuration according to the present embodiment.

  The print engine 3 executes image formation output based on the bitmap data according to the control of the engine controller 2, and inputs read image data generated by reading the output paper with a reading device to the inspection device 4. The inspection device 4 generates a master image based on the original master image input from the engine controller 2. The inspection device 4 is an image inspection device that inspects the output result by comparing the read image input from the print engine 3 with the generated master image.

  Here, a hardware configuration constituting functional blocks of the engine controller 2, the print engine 3, and the inspection apparatus 4 according to the present embodiment will be described with reference to FIG. FIG. 2 is a block diagram showing a hardware configuration of the engine controller 2 according to the present embodiment. In FIG. 2, the hardware configuration of the engine controller 2 is shown, but the same applies to the print engine 3 and the inspection apparatus 4.

  As shown in FIG. 2, the engine controller 2 according to the present embodiment has the same configuration as an information processing apparatus such as a general PC (Personal Computer) or a server. That is, the engine controller 2 according to the present embodiment includes a CPU (Central Processing Unit) 10, a RAM (Random Access Memory) 20, a ROM (Read Only Memory) 30, an HDD (Hard Disk Drive) 40, and an I / F 50. Connected through. Further, an LCD (Liquid Crystal Display) 60, an operation unit 70, and a dedicated device 80 are connected to the I / F 50.

  The CPU 10 is a calculation means and controls the operation of the entire engine controller 2. The RAM 20 is a volatile storage medium capable of reading and writing information at high speed, and is used as a work area when the CPU 10 processes information. The ROM 30 is a read-only nonvolatile storage medium and stores a program such as firmware. The HDD 40 is a non-volatile storage medium that can read and write information, and stores an OS (Operating System), various control programs, application programs, and the like.

  The I / F 50 connects and controls the bus 90 and various hardware and networks. The LCD 60 is a visual user interface for the user to check the state of the engine controller 2. The operation unit 70 is a user interface such as a keyboard and a mouse for the user to input information to the engine controller 2.

  The dedicated device 80 is hardware for realizing dedicated functions in the engine controller 2, the print engine 3, and the inspection device 4. In the case of the print engine 3, a plotter device that executes image formation output on a paper surface, A reading device for reading an image output on a paper surface. Further, the engine controller 2 and the inspection device 4 are dedicated arithmetic devices for performing image processing at high speed.

  In such a hardware configuration, a program stored in a recording medium such as the ROM 30, the HDD 40, or an optical disk (not shown) is read into the RAM 20, and the CPU 10 performs calculations according to those programs, thereby configuring a software control unit. The A functional block that realizes the functions of the engine controller 2, the print engine 3, and the inspection apparatus 4 according to the present embodiment is configured by a combination of the software control unit configured as described above and hardware.

  FIG. 3 is a block diagram showing functional configurations of the engine controller 2, the print engine 3, and the inspection apparatus 4 according to the present embodiment. As shown in FIG. 3, the engine controller 2 according to the present embodiment includes a data acquisition unit 201, an engine control unit 202, and a master image processing unit 203. The print engine 3 includes a print processing unit 301 and a reading device 302. The inspection apparatus 4 includes a read image acquisition unit 401, a master image processing unit 402, an inspection control unit 403, and a comparative inspection unit 404.

  The data acquisition unit 201 acquires bitmap data input from the DFE 1 and operates the engine control unit 202 and the master image processing unit 203, respectively. Bitmap data is information of each pixel constituting an image to be imaged and output, and the data acquisition unit 201 functions as a pixel information acquisition unit. The engine control unit 202 is an output execution control unit that causes the print engine 3 to execute image formation output based on the bitmap data transferred from the data acquisition unit 201.

  The master image processing unit 203 is a configuration according to the gist of the present embodiment, and generates the above-described original master image based on the bitmap data transferred from the data acquisition unit 201. At that time, the master image processing unit 203 generates an original master image subjected to the compression processing according to the gist of the present embodiment, and transmits the original master image to the inspection apparatus 4. That is, the master image processing unit 203 functions as an inspection image processing unit. This process will be described in detail later.

  The print processing unit 301 acquires bitmap data input from the engine controller 2, executes image formation output on the printing paper, and outputs printed paper. The print processing unit 301 according to the present embodiment is realized by a general electrophotographic image forming mechanism. The reading device 302 reads an image formed on the paper surface of the printing paper that has been printed and output by the print processing unit 301, and outputs the read data to the inspection device 4. Further, as described above, the reading device 302 generates a preprint image by scanning the preprint paper and outputs the preprint image to the inspection device 4.

  Here, the mechanical configuration of the print processing unit 301 and the reading device 302 will be described with reference to FIG. As shown in FIG. 4, the print processing unit 301 according to the present embodiment has a configuration in which image forming units 106 of respective colors are arranged along a conveyor belt 105 that is an endless moving unit, and is a so-called tandem type. It is said that. That is, the conveyance belt 105, which is an intermediate transfer belt on which an intermediate transfer image is formed to be transferred from a paper feed tray 101 to a paper (an example of a recording medium) 104 that is separated and fed by a paper feed roller 102 and a separation roller 103. A plurality of image forming units (electrophotographic process units) 106BK, 106M, 106C, and 106Y are arranged in this order from the upstream side in the transport direction of the transport belt 105.

  The plurality of image forming units 106BK, 106M, 106C, and 106Y have the same internal configuration except that the colors of the toner images to be formed are different. The image forming unit 106BK forms a black image, the image forming unit 106M forms a magenta image, the image forming unit 106C forms a cyan image, and the image forming unit 106Y forms a yellow image. In the following description, the image forming unit 106BK will be described in detail. However, since the other image forming units 106M, 106C, and 106Y are the same as the image forming unit 106BK, the image forming units 106M, 106C, and 106Y are similar to the image forming unit 106BK. As for each of the components, only the symbols distinguished by M, C, and Y are displayed in the drawing in place of the BK attached to each component of the image forming unit 106BK, and the description thereof is omitted.

  The conveying belt 105 is an endless belt, that is, an endless belt that is stretched between a driving roller 107 and a driven roller 108 that are rotationally driven. The drive roller 107 is driven to rotate by a drive motor (not shown), and the drive motor, the drive roller 107, and the driven roller 108 function as a drive unit that moves the conveyance belt 105 that is an endless moving unit. .

  During image formation, the first image forming unit 106BK transfers a black toner image to the conveyance belt 105 that is driven to rotate. The image forming unit 106BK includes a photoconductor drum 109BK as a photoconductor, a charger 110BK arranged around the photoconductor drum 109BK, an optical writing device 200, a developing device 112BK, a photoconductor cleaner (not shown), and a static eliminator. 113BK and the like. The optical writing device 200 is configured to irradiate light to the respective photosensitive drums 109BK, 109M, 109C, and 109Y (hereinafter collectively referred to as “photosensitive drum 109”).

  In the image formation, the outer peripheral surface of the photosensitive drum 109BK is uniformly charged by the charger 110BK in the dark, and then writing is performed by light from a light source corresponding to the black image from the optical writing device 200. An electrostatic latent image is formed. The developing device 112BK visualizes the electrostatic latent image with black toner, thereby forming a black toner image on the photosensitive drum 109BK.

  This toner image is transferred onto the conveyance belt 105 by the action of the transfer unit 115BK at a position (transfer position) where the photosensitive drum 109BK and the conveyance belt 105 are in contact with or closest to each other. By this transfer, an image of black toner is formed on the conveyance belt 105. After the transfer of the toner image is completed, unnecessary toner remaining on the outer peripheral surface of the photosensitive drum 109BK is wiped off by the photosensitive cleaner, and then the charge is removed by the charge eliminator 113BK, and waits for the next image formation.

  As described above, the black toner image transferred onto the conveying belt 105 by the image forming unit 106BK is conveyed to the next image forming unit 106M by driving the rollers of the conveying belt 105. In the image forming unit 106M, a magenta toner image is formed on the photosensitive drum 109M by a process similar to the image forming process in the image forming unit 106BK, and the toner image is superimposed and transferred onto the already formed black image. Is done.

  The black and magenta toner images transferred onto the conveying belt 105 are further conveyed to the next image forming units 106C and 106Y, and the cyan toner image formed on the photosensitive drum 109C and the photosensitive member are subjected to the same operation. The yellow toner image formed on the body drum 109Y is superimposed and transferred on the already transferred image. Thus, a full-color intermediate transfer image is formed on the conveyance belt 105.

  The sheets 104 stored in the sheet feed tray 101 are sent out in order from the top, and the intermediate transfer image formed on the conveyance belt 105 is transferred at a position where the conveyance path is in contact with or closest to the conveyance belt 105. It is transferred onto the paper. As a result, an image is formed on the surface of the sheet 104. The sheet 104 on which the image is formed on the sheet surface is further conveyed, the image is fixed by the fixing device 116, and then discharged to the outside of the image forming apparatus.

  In the fixing device 116, the toner image transferred onto the paper surface is fixed on the paper surface by heat. For this reason, when the transfer paper passes through the high-temperature fixing device 116, moisture evaporates, and the paper shrinks so that the image on the transfer paper becomes smaller than the original image. When the transfer paper having the image reduced in this way is read by the reading device 302, a read image smaller than the original image is generated.

  In the case of double-sided printing, the sheet on which the image is fixed is conveyed to the reverse path, and after being reversed, is conveyed again to the transfer position. The sheet on which the image is formed and fixed on one side or both sides is conveyed to the reading device 302. Thereby, one side or both sides are imaged by the reader 302, and a read image that is an image to be inspected is generated.

  Next, each configuration of the inspection apparatus 4 will be described with reference to FIG. 3 again. The read image acquisition unit 401 acquires image information generated by reading the paper surface of the printing paper by the reading device 302 in the print engine 3 and inputs the image information to the comparison inspection unit 404 as an image to be inspected.

  The master image processing unit 402 acquires the original master image input from the engine controller 2 as described above, and generates a master image that is an inspection image for comparison with the image to be inspected. At this time, the master image processing unit 402 generates a master image by performing a decompression process corresponding to the compression method used when the master image processing unit 203 transmits information. This process will be described in detail later.

  The inspection control unit 403 is a control unit that controls the operation of the entire inspection apparatus 4, and each component included in the inspection apparatus 4 operates according to the control of the inspection control unit 403. The comparison inspection unit 404 compares the read image input from the read image acquisition unit 401 with the master image generated by the master image processing unit 402, and determines whether or not the intended image formation output is being executed. It is an image inspection unit.

  Next, details of functions included in the master image processing unit 203 will be described with reference to FIG. FIG. 5 is a block diagram illustrating an internal configuration of the master image processing unit 203. As illustrated in FIG. 5, the master image processing unit 203 includes a small-value / multi-value conversion processing unit 231, a resolution conversion processing unit 232, a color conversion processing unit 233, and a master image transmission unit 234. Note that the master image processing unit 203 according to the present embodiment is realized by the dedicated device 80 described with reference to FIG. 2, that is, the hardware operating according to software control.

  The low-value / multi-value conversion processing unit 231 executes a low-value / multi-value conversion process on the binary image expressed in colored / colorless to generate a multi-value image. The bitmap data according to the present embodiment is information to be input to the print engine 3, and the print engine executes image formation output based on CMYK (Cyan, Magenta, Yellow, blackK) color binary images. On the other hand, the read image, which is the image to be inspected, is a multi-valued image of RGB (Red, Green, Blue), which is the basic three primary colors, and is a multi-valued image. The image is converted into a multi-valued image. As the multivalued image, for example, an image expressed by 8 bits for each of CMYK can be used.

  In this embodiment, the print engine 3 executes image formation output based on CMYK binary images, and the master image processing unit 203 includes the low-value multi-value conversion processing unit 231. Is an example. That is, when the print engine 3 executes image formation output based on a multi-value image, the low-value multi-value conversion processing unit 231 can be omitted.

  The resolution conversion processing unit 232 performs resolution conversion so that the resolution of the multi-value image generated by the small-value multi-value conversion processing unit 231 matches the resolution of the read image that is the image to be inspected. In the present embodiment, since the reading device 302 generates a 200 dpi read image, the resolution conversion processing unit 232 converts the resolution of the multi-valued image generated by the small-value multi-value conversion processing unit 231 to 200 dpi.

  The color conversion processing unit 233 acquires an image whose resolution has been converted by the resolution conversion processing unit 232 and performs color conversion. As described above, since the read image according to the present embodiment is an RGB format image, the color conversion processing unit 233 converts the CMYK format image after the resolution conversion by the resolution conversion processing unit 232 into the RGB format. . As a result, a 200 dpi multi-valued image expressed by 8 bits (total 24 bits) of each RGB color is generated for each pixel.

  Here, the color conversion processing unit 233 according to the present embodiment does not simply convert an image in the CMYK format into the RGB format, but performs conversion while compressing based on the processing according to the gist of the present embodiment. The original master image described above is generated. As described above, when the color conversion processing unit 233 performs color conversion from the CMYK format to the RGB plain, the gist of the present embodiment is to determine the compression format based on the pixel color, that is, the pixel value.

  By performing the compression format based on the pixel value, the compression efficiency can be improved without increasing the amount of calculation required for compression. However, the higher the image resolution, the greater the amount of calculation for determining the pixel value. On the other hand, in the present embodiment, since it is premised that the pixel value of each pixel is originally processed by color conversion, the huge amount of calculation described above is added by determining the compression format simultaneously with the processing. Therefore, it is possible to realize the determination of the compression format based on the pixel value.

  The master image transmission unit 234 transmits the original master image generated by the small-value / multi-value conversion processing unit 231, the resolution conversion processing unit 232, and the color conversion processing unit 233 to the master image processing unit 402 of the inspection apparatus 4. As described above, since the original master image is in a compressed state, the amount of information to be transmitted by the master image transmission unit 234 is reduced.

  Next, a characteristic compression format in the present embodiment will be described. FIG. 6A is a diagram illustrating an example of a master image in the state of CMYK-based paper generated through the small-value / multi-value conversion processing unit 231 and the resolution conversion processing unit 232. A hatched portion indicated by a solid line in FIG. A monochrome portion by gray scale or black and white binary, and a shaded portion by broken lines in the figure are color portions having a color, and the other portions are blank portions.

In the compression format according to this embodiment, the color of the image as shown in FIG. 6A is determined in units of main scanning lines, and the image is divided as shown by the dotted line in FIG. 6B. Specifically, white areas W ₁ and W ₂ that are blank spaces and no colored pixels, and monochrome areas B ₁ and B _{2 in} which the colored pixels are only a monochrome portion such as a grayscale or monochrome binary, The range of the master image is determined based on the color area F in which a colored portion includes a color portion having a color.

The area determination as shown in FIG. 6B is performed at the same time when the color conversion processing unit 233 converts the image in the CMYK format into the RGB format. Generally, when converting from CMYK to RGB, a conversion formula as shown in the following formula (1) is used.

  When color conversion is performed on the white area portion, that is, the portion where C = M = Y = K = 0, based on the above equation (1), the result is R = G = B = 1. That is, in the case of 8 bits (0 to 255) for each RGB color, R = G = B = 255. Further, when color conversion is performed on the monochrome area portion, that is, the portion where C = M = Y = 0 and K ≠ 0 based on the above formula (1), the result is R = G = B. That is, in the case of 8 bits (0 to 255) for each RGB color, R = G = B ≠ 255.

  Thus, if the color type of each area is known, information can be compressed according to each color type, and information compression and transfer can be performed efficiently. For example, in the case of a white area, if it is known that it is a white area, a white value may be substituted on the master image processing unit 402 side, and information indicating the white area and information indicating the leading end and end of the area , There is no need to transfer the white data itself.

  In addition, color conversion from CMYK data to RGB data is performed using a color conversion table configured to convert values according to a calculation such as the above equation (1). On the other hand, for areas that are known to be white, it is possible to determine that R = G = B = 255 without performing color conversion processing, thereby reducing the amount of processing. Is possible.

  In the case of a monochrome area, since R = G = B as described above, if data of any one of the three RGB colors is transferred, the same value as the transferred one color is used for the subsequent two colors. It is possible. Similarly, in the case of a monochrome area, if color conversion is performed for any one of the three RGB colors, the same value as the converted value can be used for the subsequent two colors. The gist of the present embodiment is to determine the compression mode of the master image on the basis of such a principle, compress it, and transmit it as the original master image.

The operation of the color conversion processing unit 233 according to this embodiment will be described with reference to FIG. As illustrated in FIG. 7, when the color conversion processing unit 233 according to the present embodiment acquires CMYK format image data after resolution conversion from the resolution conversion processing unit 232, the page _S that is the page start address and the page end address The page _E which is an address is set (S701). As described with reference to FIG. 6B, since the determination is performed in units of main scanning lines in the present embodiment, the address set in S701 is information indicating the number of lines.

Next, the color conversion processing unit 233, based on the CMYK respective data constituting the image data, C ≠ 0 and becomes closest to the page start address C _S and most pages terminating near the address C _E, the M ≠ 0 The address M _S closest to the top and the address M _E closest to the end of the page, the address Y _S closest to the top where Y ≠ 0, the address Y _E closest to the end of the page, and the address K closest to the top where K ≠ 0 _S and most pages terminating near the address _{K E} respectively extracted (S702).

Next, based on the extraction result of S702, the color conversion processing unit 233 sets the color _S closest to the top of the page among C _S , Y _S , and M _S as the color _S , and the most page among C _E , Y _E , and M _E. Those near the end are set as Color _E (S703). Then, the color conversion processing unit 233 determines whether or not the range from Color _S to Color _E , that is, the full color range exceeds a predetermined threshold (S704).

  In the compression method according to the present embodiment, as described above, for the white area and the monochrome area, the optimum compression processing and color conversion processing are used to improve processing efficiency and transfer efficiency. Therefore, if the full color range is wide in the entire image, the effect of improving processing efficiency and transfer efficiency is low.

  Therefore, when the color area exceeds the predetermined threshold (S704 / NO), the color conversion processing unit 233 determines whether to perform color processing, that is, normal color conversion and data transfer from the top to the end of the page. (S707), the process ends. On the other hand, if the color area is equal to or smaller than the predetermined threshold value, the page top process (S705) and the page end process (S706) are performed, and the process ends.

FIG. 8 is a flowchart showing the contents of the page head process in S705. As shown in FIG. 8, the color conversion processing unit 233 determines whether or not K _S is on the page head side with respect to Color _S , that is, whether or not there is a monochrome area in front of the color area on the page head side. Judgment is made (S801). If K _S is to top side of the Color _S (S801 / YES), then, the color conversion processing unit 233 determines the range of monochromatic area in the page head side to or greater than a predetermined threshold value (S802).

  The determination in S802 is processing for determining whether or not the total processing time can be reduced by processing the monochrome area on the top side of the page as a monochrome area separately from the color area. That is, if the monochrome area is narrow, even if the monochrome process is performed and the transfer time is somewhat shortened, the reduced amount is absorbed by the overhead time for switching to the monochrome process. .

Results of the determination of S802, if the monochrome areas is equal to or greater than a predetermined threshold value (S802 / YES), the color conversion processing unit 233, a page head portion, i.e. the portion of _{W 1} shown in FIG. 6 (b) white processing, i.e. Then, a process of generating information indicating the white area and the address from the front end to the end of the area is performed. Also, monochrome processing portion B ₁ is a monochrome area from K _S, i.e., RGB one color only the color conversion, produces only one color in the image. Further, the portion of F, which is the color area from Color _S , is subjected to color processing, that is, color conversion is performed for all RGB colors, and RGB image data is generated as usual (S803).

On the other hand, if the monochrome area is less than the predetermined threshold (S802 / NO), the color conversion processing unit 233 performs white processing on the top portion of the page and performs color processing on the area after K _S (S804). When it is determined at S801, if there is no to top side than _{K S} is Color _S (S801 / NO), the color conversion processing unit 233, a page head portion as well as white-processing, color processing for subsequent Color _S Area (S805).

FIG. 9 is a flowchart showing the contents of the page end process in S706. As shown in FIG. 9, the color conversion processing unit 233, whether or not K _E is the page end side of the Color _E, i.e., the page termination side, determines whether there is a monochromatic area after the color area (S901). If K _E is the page end side of the Color _E (S901 / YES), then, the color conversion processing unit 233 determines the range of monochrome area on the page terminating party to or greater than a predetermined threshold value (S902).

The determination in S902 is the same as in S802. Results of the determination of S902, if the monochrome areas is equal to or greater than a predetermined threshold value (S902 / YES), the color conversion processing unit 233 performs color processing until Color _E performs monochrome processing until then _{K E,} until then the page end White processing is performed (S903).

On the other hand, if the monochrome areas is less than the predetermined threshold value (S902 / NO), the color conversion processing unit 233 performs color processing until _{K E,} the white processing until then page end (S904). When it is determined at S901, if _{K E} is not a page end side of the Color _E (S901 / NO), the color conversion processing unit 233 performs color processing until Color _E, the white processing until then page termination ( S905). By such processing, the processing by the color conversion processing unit 233 according to the present embodiment is completed.

  FIG. 10 is a diagram illustrating data of the original master image generated by the processes of FIGS. 7 to 9. FIG. 10 shows data generated through S803 in FIG. 8 and S903 in FIG. As shown in FIG. 10, the data of the original master image generated through S803 and S903 includes the white area, the monochrome area, and the color area according to the image configuration as shown in FIG. Contains information about.

  As described above, if the white area is a white area and the range of the area is known, the image data itself indicating white is unnecessary. Therefore, as shown in FIG. 10, the white area information includes “white area identifier” and “white area position information”.

“White area identifier” is information indicating a white area. “White area position information” specifies the area of the white area by specifying the start line and end line of the area, such as “Page _S- K _S ” or “K _E -Page _E ”. It is information to do.

  Since the monochrome area is R = G = B, the same value can be used for the other two color data if only one color RGB data is found. Therefore, as shown in FIG. 10, the monochrome area information includes “monochrome area identifier” and “monochrome area image information” of only one of RGB.

  “Monochrome area identifier” is information indicating a monochrome area. In addition, “monochrome area image information” is a pixel value of only one of RGB colors as described above. In other words, out of pixel values represented by three colors of RGB, values for two colors are thinned out. Value. In the present embodiment, from the above-mentioned meaning that R = G = B, two colors are thinned out to obtain a value for one color, but even if one color is thinned out, an information reduction effect can be obtained. It is.

  On the other hand, since it is necessary to describe all the colors of RGB for the color area, the color area information includes “color area identifier” and “color area image information” including information of each RGB color.

Each information shown in FIG. 10 corresponds to a range delimited by the address of the main scanning line as shown in FIG. 6B. That is, in the example shown in FIG. 6B, the white area W ₁ , monochrome area B ₁ , color area F, monochrome area B ₂ , and white area W ₂ are arranged in this order from the top of the page. As shown in FIG. 10, information corresponding to each area is also arranged in the original master image.

  When the information is generated through S707 in FIG. 7, the original master image is generated only from the information of the color area to which the “color area identifier” is attached, among the information shown in FIG. This is information that is not compressed at all, and is the same information as the information of the master image that is finally generated.

  8, when the information is generated through S804 or S805, the information on the upper side is omitted from the information of the monochrome area with the monochrome area identifier “shown in FIG. When the information is generated through S904 or S905 in FIG. 9, the information on the lower side of the information of the monochrome area with the monochrome area identifier “shown in FIG. 10 is omitted.

  Information of the original master image as shown in FIG. 10 generated by the color conversion processing unit 233 is transmitted to the master image processing unit 402 of the inspection apparatus 4 by the master image transmission unit 234. Then, when acquiring the information of the original master image as shown in FIG. 10, the master image processing unit 402 expands the information compressed by the process corresponding to the identifier indicating each area, and generates a master image.

  In the case of information with “white area identifier” added thereto, the master image processing unit 402 generates RGB format information indicating white for the range indicated by “white area position information”. The information of white RGB format is R = G = B = 255 in the case of 8 bits per pixel. In the case of information with “monochrome area identifier” attached, the master image processing unit 402 sets image information for one color included as “monochrome area image information” as image information for each of RGB.

  The master image processing unit 402 generates master image information by combining the white area and monochrome area information generated in this way with “color area image information” to which a “color area identifier” is attached. . When combining the information of the white area, the monochrome area, and the color area, the master image processing unit 402 combines the information according to the order of information in the original master image as shown in FIG.

  As described above, in the image forming system according to the present embodiment, when the master image is input to the inspection apparatus 4, the engine controller 2 performs the master image based on the print data for causing the print engine 3 to execute the image forming output. In this case, the white and monochrome images are transferred to the original master image compressed by the corresponding compression method, and the information is transferred. Thereby, the information transfer efficiency to the inspection apparatus 4 can be improved.

  In such a process, a process for analyzing the contents of the pixels constituting the print data is required, and a process for compressing information is also required, which causes a problem of processing load. On the other hand, when generating a master image, a process for converting each pixel value in the CMYK format to the RGB format is originally required, and the additional processing of such a process greatly increases the processing load. It is possible to avoid it. In addition, a dedicated hardware accelerator provided for image processing when generating a master image can be used, and more efficient processing can be realized.

  Further, as described above, the information compression format according to the present embodiment is simple according to the color of the image such as plain, monochrome, or color. For this reason, the master image processing unit 402 can decompress the information by a simple process according to each identifier such as “white area identifier”, “monochrome area identifier”, and “color area identifier”. However, there is no problem of processing load.

  Further, conventionally, since print data in CMYK format is transmitted from the engine controller 2 to the inspection apparatus 4 and a master image is generated in the inspection apparatus 4, high resolution is achieved for fine image formation output by the print engine 3. It was necessary to transfer the print data composed of In contrast, the master image processing unit 203 of the engine controller 2 according to the present embodiment reduces the resolution of the print data in accordance with the reading result by the reading device 302. This also makes it possible to reduce the amount of information transferred and shorten the transfer time.

  Further, the master image processing unit 203 of the engine controller 2 according to the present embodiment converts the print data in the CMYK format into the RGB format and generates an original master image. Therefore, the data is simply reduced by one color. From this point, the amount of information transferred can be reduced and the transfer time can be shortened.

  As described above, in the image forming system according to the present embodiment, the reference data is transferred to the inspection apparatus in the image inspection by comparing the image obtained by reading the output result of the image formation output with the master image. Efficiency can be improved.

In the above embodiment, in S701~S703 of FIG. 7, the color conversion processing unit 233, _{K S} and Color _S such information, i.e., information of a result of analyzing the contents of the pixels constituting the print data (hereinafter , “Analysis result information”) is generated as an example. However, if there is other information that can be used as analysis result information, the color conversion processing unit 233 does not need to perform analysis, and the system configuration can be made more efficient. Such an example will be described.

  FIG. 11 is a diagram illustrating an example in which when the DFE 1 generates bitmap data in the CMYK format, information corresponding to the analysis result information described above is generated and input to the engine controller 2 together with the bitmap data. . The DFE 1 generates bitmap data in the CMYK format based on image information described in a predetermined format such as a PDL (Page Description Language) format included in a print job received from the outside. Therefore, in the process of analysis of image information and output of bitmap data, it is possible to generate the above-described analysis result information as an additional process, and this also achieves the same effect as the above embodiment. It is possible.

  FIG. 12 is a diagram illustrating an example of the case where the engine controller 2 generates information corresponding to the analysis result information described above when controlling the print engine 3 based on the print data received from the DFE 1. The engine control unit 202 of the engine controller 2 transfers the bitmap data acquired by the data acquisition unit 201 to the print processing unit 301 when the print engine 301 executes image formation output. At this time, by analyzing the content of the data to be transferred, it is possible to generate the analysis result information described above as an additional process, and it is also possible to obtain the same effect as in the above embodiment. is there.

  In the above embodiment, the case where the compression processing based on the analysis result information described above is performed as an example when the CMYK data is converted into the RGB data has been described. However, if analysis result information is generated regardless of the conversion from CMYK data to RGB data as in the examples of FIGS. 11 and 12, the CMYK data itself is not converted without conversion to RGB data. It is possible to compress based on the analysis result information. In this case, in monochrome processing, only K information of CMYK is generated as information of the original master image. Then, the master image acquisition unit 402 of the inspection apparatus 4 performs conversion from CMYK data to RGB data.

  In the above embodiment, the data transfer amount is reduced by specifying the “white area identifier” and the “white area position information” for the white area, that is, the white area that does not require ink output. The case has been described as an example. However, such an aspect is not limited to the white area, and can be similarly applied to solid areas of the same color. The color conversion unit 233 specifies not only the white area but also a solid painting area such as “white area position information”, if the solid painting area of the same color is greater than or equal to a predetermined range. By generating such information, it is possible to reduce the amount of data as in the white area.

  Further, in the above embodiment, as illustrated in FIG. 6B, the case where the range for determining the compression method is divided in line units has been described as an example. This is because the information transfer from the engine controller 2 to the inspection device 4 is executed in units of lines, so that the processing efficiency can be improved by switching the compression method in units of lines.

On the other hand, since about half of the range of the monochromatic area B ₁ in FIG. 6 (b) is a white area, if it is possible to omit the information transfer of the portion as white areas W _1, W _2, required for the information transfer Time can be further reduced. Such an aspect can be realized, for example, by generating mixed area information as monochrome area B ₁ information, as shown in FIG.

  As shown in FIG. 13, the mixed area information includes monochrome area information and white area information. The monochrome area information includes “monochrome area identifier”, “monochrome area image information”, and “monochrome area position information”. “Monochrome area identifier” and “monochrome area image information” are the same information as described above.

  “Monochrome area position information” is information indicating a range to be processed as a monochrome area. In the example of FIG. 13, the position on the image is represented by the number of lines and the number of dots indicating the number of pixels on the main scanning line, and the upper left position and the lower right position of the range defined by the rectangle The range is expressed by specifying the position. The example of FIG. 13 is an example when the number of lines and the number of dots are specified as shown in FIG.

Note that “monochrome area image information” in the example of FIG. 13 is not image information for each main scanning line but image information in a range defined by “monochrome area position information”. That is, in the case of the example in FIG. 14, the image information of the pixels from Dot ₁ to Dot ₂ is included as “monochrome area image information” for the main scanning lines from K _S to Color _S.

  Also, as shown in FIG. 13, the white area information includes “white area identifier” and “white area position information”. The “white area identifier” is the same information as the information described above. The “white area position information” in the example of FIG. 13 is information whose range is demarcated based on the main scanning line position and the dot position, similarly to the “monochrome area position information” described above.

Further, in the above embodiment, the start line of the monochrome area and the start line of the color area are determined from the start of the page of the image to be output, and the end line of the monochrome area and the end line of the color area are determined on the page end side. doing. In other words, this is processing for determining the presence / absence of processing as a monochrome area and the starting point of the area. Such an aspect simplifies the process of generating information such as C _S , Y _S , M _S , K _S , C _E , Y _E , M _E , and K _S in S702 of FIG. It is preferably solved.

However, when an image as shown in FIG. 15 is the target, Line ₁ to Line ₄ are processed as color areas even though a wide range from Line ₂ to Line ₃ is a monochrome area. Such a problem is solved by generating information on the presence or absence of colors other than monochrome, that is, whether or not any of CMY is zero (hereinafter referred to as “line color information”) for all lines. Is possible.

That is, the color conversion processing unit 233 refers to the above-described line color information in the color processing in the processing shown in FIGS. 8 and 9, and if the number of monochrome only lines exceeds a predetermined number of lines, the color processing to monochrome processing is performed. Switch to processing. Thereby, in the range from Line ₂ to Line ₃ shown in FIG. 15, the information of the original master image is generated by the monochrome process, and the above-described problems can be solved.

  Such an aspect can be applied not only to the monochrome area but also to the white area. In other words, the above-described line color information can be realized by generating information indicating any one of “plain”, “monochrome”, and “color” for each line. The operation in such a case will be described with reference to FIG.

  As illustrated in FIG. 16, when the color conversion processing unit 233 starts the color conversion process, the color conversion processing unit 233 refers to the line color information regarding the processing target line (S1601). When the processing target line is only white (S1601 / YES), the color conversion processing unit 233 determines whether or not the white only line continues for a predetermined number of lines (S1602). That is, the color conversion processing unit 233 determines whether or not the white area is greater than or equal to a predetermined range.

  As a result of the determination, if the number of white-only lines continues for a predetermined number of lines or more (S1602 / YES), the color conversion processing unit 233 performs white processing on the white-only lines that continue for the predetermined number of lines (S1603). The color conversion processing unit 233 continues the white processing until the white-only line ends (S1604 / NO).

  On the other hand, if the processing target line is not white, the color conversion processing unit 233 determines whether the processing target line is monochrome (S1606). In the determination in S1602, when the number of white-only lines does not continue for a predetermined number or more (1602 / NO) and the processing target line is monochrome (S1606 / YES), the color conversion processing unit 233 Alternatively, it is determined whether or not monochrome lines continue for a predetermined number of lines (S1607).

  As a result of the determination, if the number of white or monochrome lines continues for a predetermined number of lines or more (S1607 / YES), the color conversion processing unit 233 performs color processing for the white or monochrome lines that continue for the predetermined number of lines. Execute (S1608). The color conversion processing unit 233 continues the monochrome process until the white or monochrome line ends (S1609 / NO).

  If the line to be processed is not monochrome (S1606 / NO) and if the determination in S1607 is that the number of white or monochrome lines does not continue for a predetermined number of lines (S1607 / NO), the color conversion processing unit 233 Color processing is executed for the line to be processed (S1610).

  After white processing, when the line of only white is finished (S1604 / YES), after monochrome processing, when the white or monochrome line is finished (S1609 / YES), and when color processing is finished, the color conversion processing unit In step S1605, it is determined whether the process has been completed up to the end of the page. If the process has been completed to the end of the page (S1605 / YES), the process is completed. If the process has not been completed to the end of the page (S1605 / NO), the processes from S1601 are repeated. By such processing, it is possible to perform optimum compression processing according to the color paper of the image even for an image as shown in FIG.

  In the above embodiment, as described with reference to FIG. 10, the case where information obtained by arranging image information and information indicating the range of the white area according to a predetermined rule is used as the original master image has been described as an example. In addition, the engine controller 2 separately generates image information and information indicating the range for each area and transmits the information to the inspection device 4. The inspection device 4 performs mastering based on the information indicating the range for each area and the image information. An image can also be generated, and the same effect as described above can be obtained.

  In the above-described embodiment, the case where the master image processing unit 402 of the inspection apparatus 4 generates a master image by expanding compressed information has been described as an example. However, if the contents of the master image can be determined based on the compression method as described above, the master image generation process by decompressing the information can be omitted, and the master image is stored on the inspection apparatus 4 side. It is possible to reduce the memory area.

  That is, when the inspection control unit 403 causes the comparison inspection unit 404 to compare images, the inspection control unit 403 inputs a range to be compared, that is, a read image having a predetermined number of lines, from the read image acquisition unit 401, and a predetermined value corresponding to the range. An image of the number of lines is acquired from the original master image. At this time, if the target range is a white region, the inspection control unit 403 generates information indicating white, that is, information of R = G = B = 255, for the number of target lines, and inputs the information to the comparison inspection unit 404. .

  If the target range is a monochrome region, the inspection control unit 403 inputs image information for one color included as “monochrome area image information” to the comparison inspection unit 404 as RGB image information. To do. According to such an aspect, it is possible to cause the comparative inspection unit 404 to perform a comparative inspection without decompressing the original master image that is compressed information and generating the original master image. In other words, this aspect is equivalent to executing a comparison inspection by expanding a portion to be subjected to a comparison inspection each time in the original master image which is compressed information.

  In the above embodiment, it is assumed that there are blank areas at the upper and lower page ends of a general paper document. As shown in FIGS. 8 and 9, the upper and lower page portions are shown. Was described on the premise of white processing. However, depending on the image to be output, the upper end portion of the page is not limited to the blank area, and may be a narrow blank area where the compression effect is low.

Therefore, in FIG. 8, the color conversion processing unit 233 confirms whether or not there is a margin at the upper end of the page by confirming that K _S , Color _S and Page _S are different before S801. Also good. Further, by comparing K _S , Color _S and Page _S , it may be confirmed whether or not the margin range of the upper end portion of the page is wide enough to obtain the compression effect.

Also in FIG. 9, the color conversion processing unit 233, after the _S902, K E, by where the Color _E and Page _E confirms different, may be confirmed whether there is a margin in the page bottom portion . Further, by comparing K _E , Color _E and Page _E , it may be confirmed whether or not the margin range at the lower end of the page is wide enough to obtain the compression effect.

  If there is no margin or the margin range is not wide enough to obtain the compression effect, the color conversion processing unit 233 omits the white processing for each of the upper end portion and the lower end portion of the page, and performs monochrome processing or color processing. It is preferable to process the upper end portion of the page and the lower end portion of the page by processing. By such processing, it is possible to more effectively realize the compression processing according to the content of the image.

1 DFE
2 Engine controller 3 Print engine 4 Inspection device 10 CPU
20 RAM
30 ROM
40 HDD
50 I / F
60 LCD
70 Operation Unit 80 Dedicated Device 90 Bus 101 Paper Feed Tray 102 Paper Feed Roller 103 Separation Roller 104 Paper 105 Conveying Belt 106BK, 106C, 106M, 106Y Image Forming Unit 107 Drive Roller 108 Driven Roller 109BK, 109C, 109M, 109Y Photosensitive Drum 110BK Charger 111 Optical writing device 112BK, 112C, 112M, 112Y Developer 113BK, 113C, 113M, 113Y Charger 115BK, 115C, 115M, 115Y Transfer device 116 Fixing device 116 Data acquisition unit 202 Engine control unit 203 Master image processing unit DESCRIPTION OF SYMBOLS 301 Print processing part 302 Reading apparatus 401 Reading image acquisition part 402 Master image processing part 403 Inspection control part 404 Comparison inspection part 421 Low value multi-value conversion processing part 422 Zodo conversion processing section 423 color conversion processing section 424 the master image processing unit 425 preprint master registration unit 425

JP-A-8-258378

Claims (10)

An image forming control apparatus for controlling the image forming apparatus in an image inspection system for inspecting a read image obtained by reading an image formed and output on a paper surface by an image forming apparatus,
A pixel information acquisition unit that acquires pixel information that is information on an image to be imaged and output and that is information on each pixel that constitutes an image to be imaged and output;
An output execution control unit for causing the image forming apparatus to execute an image forming output based on the pixel information;
An inspection image processing unit that transmits information generated based on the pixel information for an inspection image referred to in an inspection to an inspection apparatus that inspects the read image;
The image processing unit for inspection generates information for specifying a plain area for a plain area of a predetermined range or more in the pixel information, instead of information on pixels in the range. Control device.   The inspection image processing unit generates, for each pixel, value information indicating a plurality of different color densities based on the pixel information for the inspection image. The image forming control apparatus according to claim 1, wherein the achromatic color range generates information obtained by thinning out a value of at least one of the plurality of different colors and information indicating an achromatic color.   The inspection image processing unit transmits information generated by converting the value of each pixel in the pixel information to a value specifying each value of the basic three primary colors to the inspection apparatus, and at the time of the conversion, a predetermined range or more The image forming control apparatus according to claim 1, wherein, for the plain area, information indicating the plain area is generated instead of pixel information.   The inspection image processing unit generates information indicating an achromatic color and a value of only one of the basic three primary colors for an achromatic color range of a predetermined range or more in the inspection image. The image formation control device according to claim 3.   5. The image formation control apparatus according to claim 1, wherein the inspection image processing unit generates image information in which an image size of the pixel information is changed according to the read image. 6. .   The inspection image processing unit generates information indicating a main scanning line in the range instead of information on pixels in the range when the plain range is equal to or more than a predetermined number of main scanning lines. The image formation control apparatus according to claim 1.   The inspection image processing unit performs processing in the order of a plain range, an achromatic color range, and a chromatic color range from the front end side of the pixel information image to generate information to be transmitted to the inspection apparatus. The image formation control apparatus according to claim 2, wherein the image formation control apparatus is an image formation control apparatus. The inspection image processing unit includes:
Recognizing the upper achromatic pixel closest to the upper end of the image among the achromatic colored pixels in the pixel information and the upper chromatic pixel closest to the upper end of the image among the chromatic colored pixels,
The image forming control apparatus according to claim 7, wherein the achromatic range is processed when the upper achromatic pixel is located on the upper end side of the image with respect to the upper chromatic pixel. An image formation control method for controlling the image forming apparatus in an image inspection system for inspecting a read image obtained by reading an image formed and output on a paper surface by an image forming apparatus,
Obtain pixel information that is information of an image that is an image formation output target and that is information of each pixel that constitutes an image to be imaged and output;
Causing the image forming apparatus to execute an image forming output based on the pixel information;
Information generated based on the pixel information for an inspection image referred to in the inspection is transmitted to the inspection apparatus that inspects the read image. An image formation control method for generating information for specifying a plain area in place of the pixel information of the range. An image forming control program for controlling the image forming apparatus in an image inspection system for inspecting a read image obtained by reading an image formed and output on a paper surface by an image forming apparatus,
Obtaining pixel information which is information on an image to be imaged and output, and which is information on each pixel constituting an image to be imaged and output;
Causing the image forming apparatus to execute image forming output based on the pixel information;
Transmitting information generated based on the pixel information for an inspection image referred to in an inspection to an inspection apparatus that inspects the read image;
When generating information to be transmitted to the inspection apparatus, a step of generating information indicating a plain range instead of the pixel information of the pixel range of the pixel information that is equal to or greater than a predetermined range is processed. An image forming control program which is executed by an apparatus.

Images