Image inspection device, image inspection method, and image inspection program

Abstract

To provide an image inspection device, an image inspection method and an image inspection program which can further shorten a time required in processes ranging from generation of a reference image to image inspection in comparison with in a conventional technique.SOLUTION: An image inspection device 300 comprises a first control part 501, a second control part 502, and a third control part 503. The first control part 501 controls generation of a reference image that is used for inspecting an image formed on a recording medium, on the basis of obtained image data. The second control part 502 controls formation of an image on the recording medium, on the basis of the obtained image data. The third control part 503 controls execution of an inspection based on the reference image, of the image formed on the recording medium. At least one control part of the first control part 501, the second control part 502 and the third control part 503 operates independently from the other control parts.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an image inspection device, an image inspection method, and an image inspection program. [Background technology]

[0002] Conventionally, the quality of printed matter has been inspected by comparing a scanned image of the printed matter to a pre-registered reference image. The reference image may be, for example, an image of the printed matter that has been scanned and has no quality abnormalities. Whether or not there is a quality abnormality is determined, for example, by an inspector visually checking and determining whether or not there is an abnormality. For example, the image forming apparatus described in Patent Document 1 below is known as an image forming apparatus having an image inspection unit that inspects the quality of printed matter.

[0003] However, it takes time and effort for an inspector to visually check all pages of a printed matter to obtain a reference image, as in the image forming device of Patent Document 1. In response to this, Patent Document 2 below discloses a printed matter inspection device that inspects the quality of a printed matter by comparing a document image as a reference image with a scanned image. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-146514 [Patent Document 2] Japanese Patent Application Laid-Open No. 2015-53561 Summary of the Invention [Problem to be solved by the invention]

[0005] The print inspection device of Patent Document 2 uses an original image as a reference image, thereby saving the time and effort required to create the reference image. However, it is necessary to complete the generation of the reference image (steps S101 to S115 in FIG. 6) before starting the generation of the inspection image (step S117 in FIG. 6). Therefore, there is a problem in that the process from the generation of the reference image (steps S101 to S115 in FIG. 6) to the image inspection (steps S117 to S119 in FIG. 6) still requires a considerable amount of time.

[0006] The present invention has been made in consideration of the above circumstances, and aims to provide an image inspection device, an image inspection method, and an image inspection program that can further reduce the time required for processing from the generation of a reference image to image inspection compared to conventional technology. [Means for solving the problem]

[0007] The above object of the present invention can be achieved by the following means.

[0008] (1) A first control unit controls the generation of a reference image used for inspecting an image formed on a recording medium based on acquired image data, a second control unit controls the formation of the image on the recording medium based on the acquired image data, and a third control unit controls the execution of inspection of the image formed on the recording medium based on the reference image, The first control unit, the second control unit, and the third control unit are configured by assigning a core to each control unit in a CPU. Inspection equipment.

[0010] ( 2 ) The number of cores assigned to each control unit is changed based on the test conditions of the test. 1 ) An image inspection device according to the present invention.

[0011] ( 3 ) The inspection conditions include at least one of the number of inspection exclusion areas, the number of variable areas, the amount of information in the variable areas, and the inspection level. 2 ) An image inspection device according to the present invention.

[0012] ( 4) Allocating cores to the first control unit and the third control unit with priority over the second control unit, 1 ) An image inspection device according to the present invention.

[0013] ( 5 ) Allocating cores to the first control unit with priority over the third control unit, 1 ) An image inspection device according to the present invention.

[0014] ( 6 ) When the inspection level is changed during the inspection of the image, the ratio of cores allocated to the first control unit and the third control unit is changed based on the change in the inspection level. 1 ) An image inspection device according to the present invention.

[0015] ( 7 2. The image inspection device according to claim 1, wherein the generation of the reference image and the formation of the image on the recording medium are performed in parallel. (8) An image inspection device having a reference image generation control unit that controls the generation of a reference image used to inspect an image formed on a recording medium based on acquired image data, and an inspection control unit that controls the execution of inspection of the image formed on the recording medium based on the reference image, wherein the reference image generation control unit and the inspection control unit are configured by assigning a core to each control unit in a CPU. (9) The image inspection device according to (8) above, wherein the number of cores assigned to each control unit is changed based on the inspection conditions of the inspection. (10) The image inspection device according to (9) above, wherein the inspection conditions include at least one of the number of inspection exclusion areas, the number of variable areas, the amount of information in the variable areas, and the inspection level. (11) The image inspection device according to (8) above, wherein cores are allocated to the reference image generation control unit with priority over the inspection control unit. (12) An image inspection device as described in (8) above, which, when changing the inspection level during inspection of the image, changes the proportion of cores allocated to the reference image generation control unit and the inspection control unit based on the change in the inspection level.

[0016] ( 13 1.) An image inspection method for inspecting an image formed on a recording medium based on a print job, comprising: a first control step of controlling generation of a reference image used for inspecting the image formed on the recording medium based on acquired image data; acquisition a second control step of controlling image formation on a recording medium based on the print job; acquisition a third control step of controlling inspection of an image formed on a recording medium based on the print job; The first control unit, the second control unit, and the third control unit are configured by allocating a core to each control unit in a CPU. An image inspection method comprising: (14) An image inspection method for inspecting an image formed on a recording medium based on a print job, comprising: a reference image generation control step in which a reference image generation control unit controls the generation of a reference image used to inspect an image formed on a recording medium based on acquired image data; and an inspection control step in which an inspection control unit controls the execution of inspection of the image formed on the recording medium based on the reference image, wherein the reference image generation control unit and the inspection control unit are configured in a CPU with a core assigned to each control unit. (15) The image inspection method according to (14) above, wherein the number of cores assigned to each control unit is changed based on the inspection conditions of the inspection. (16) The image inspection method according to (15) above, wherein the inspection conditions include at least one of the number of inspection exclusion areas, the number of variable areas, the amount of information in the variable areas, and the inspection level. (17) The image inspection method according to (14) above, wherein a core is allocated to the reference image generation control unit with priority over the inspection control unit. (18) An image inspection method as described in (14) above, wherein, when the inspection level is changed during inspection of the image, the proportion of cores allocated to the reference image generation control unit and the inspection control unit is changed based on the change in the inspection level.

[0017] ( 19 ) an image inspection program for inspecting an image formed on a recording medium based on a print job; M and based on the received print job, The first control unit a first control procedure for controlling generation of a reference image based on the received print job; The second control unit a second control procedure for controlling image formation on a recording medium based on the received print job; The third control unit a third control procedure for controlling inspection of an image formed on the recording medium; The first control unit, the second control unit, and the third control unit are configured by allocating a core to each control unit in a CPU. An image inspection program characterized by: (20) An image inspection program for inspecting an image formed on a recording medium based on a print job, the image inspection program having a reference image generation control procedure in which a reference image generation control unit controls the generation of a reference image used to inspect an image formed on a recording medium based on received image data, and an inspection control procedure in which an inspection control unit controls the execution of inspection of the image formed on the recording medium based on the reference image, wherein the reference image generation control unit and the inspection control unit are configured in a CPU with a core assigned to each control unit. (21) The image inspection program according to (20) above, which changes the number of cores assigned to each control unit based on the inspection conditions of the inspection. (22) The image inspection program according to (21) above, wherein the inspection conditions include at least one of the number of inspection exclusion areas, the number of variable areas, the amount of information in the variable areas, and the inspection level. (23) The image inspection program according to (20) above, wherein a core is allocated to the reference image generation control unit with priority over the inspection control unit. (twenty four) The image inspection program described in (20) above, wherein when the inspection level is changed during inspection of the image, the ratio of cores allocated to the reference image generation control unit and the inspection control unit is changed based on the change in the inspection level. [Effects of the Invention]

[0018] According to the present invention, at least one of the first, second, and third control units operates independently of the other control units. Therefore, at least one of the steps of generating a reference image, forming an inspection image, and inspecting the reference image can be performed in parallel with the other steps, thereby reducing the time required for processing from generating the reference image to inspecting the image. As a result, productivity of printed matter is improved. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a schematic block diagram of a printing system according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic block diagram illustrating the configuration of the image forming system shown in FIG. [Figure 3] 3 is a block diagram for explaining an outline of the control operations of the control unit and the print controller unit shown in FIG. 2. FIG. [Figure 4]2 is a flowchart illustrating a processing procedure of an image inspection method performed by the image forming system shown in FIG. 1. [Figure 5] 5 is a subroutine flowchart illustrating the details of inspection of an inspection image in the flowchart shown in FIG. 4. [Figure 6] FIG. 2 is a schematic diagram showing the time series of processes of acquiring an original image, generating a reference image, forming an inspection image, and inspecting the inspection image. [Figure 7] FIG. 10 is a schematic diagram showing, in chronological order, the processes of acquiring an original image, generating a reference image, forming an inspection image, and inspecting the inspection image when recovery printing is performed. [Figure 8] FIG. 10 is a schematic block diagram illustrating the configuration of an image forming system according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are designated by the same reference numerals, and duplicate explanations will be omitted. Furthermore, the dimensional proportions in the drawings are exaggerated for the convenience of explanation, and may differ from the actual proportions.

[0021] (First embodiment) <Printing system configuration> FIG. 1 is a schematic block diagram of a printing system according to a first embodiment of the present invention, and FIG. 2 is a schematic block diagram illustrating the configuration of the image forming system shown in FIG.

[0022] 1, the printing system 100 includes a client terminal 200 and an image forming system 300. The client terminal 200 and the image forming system 300 are connected to each other via a communication line 400 so that they can communicate with each other.

[0023] The client terminal 200 may be, for example, a personal computer, a tablet terminal, a smartphone, or the like. A printer driver for converting manuscript data into a print job is installed in the client terminal 200. The printer driver generates a print job in a format compatible with the print controller unit 320 (see FIG. 2) of the image forming system 300, and transmits the print job to the image forming system 300 via a communication line 400. The client terminal 200 also has a display that can display the inspection results of the printed matter (good / defective), images of defective printed matter, etc.

[0024] A print job includes, for example, print data in PDL (Page Description Language) format and job information. The print data includes, for example, print data consisting of pages 1 to n. The job information includes, for example, print settings such as the number of pages, number of copies, paper (recording medium) type, size, basis weight, single-sided printing / double-sided printing, and inspection settings (inspection on / off, inspection level). By turning the inspection setting on, the user can issue an instruction to the image forming system 300 to inspect the image.

[0025] The communication line 400 may be a LAN (Local Area Network) that connects computers or network devices together according to a predetermined standard, or a WAN (Wide Area Network) that connects LANs together via a dedicated line, etc. Examples of predetermined standards include Ethernet (registered trademark), FDDI (Fiber Distributed Data Interface), and Wi-Fi (Wireless Fidelity).

[0026] The number of the above components connected to the communication line 400 is not limited to the example shown in FIG.

[0027] <Configuration of Image Forming System 300> 1 and 2, the image forming system 300 includes a control unit 310, a print controller unit 320, an image forming unit 330, an image reading unit 340, an image inspection unit 350, an operation display unit 360, a paper feed unit 370, a reference image generation unit 380, and a storage device 390. The image forming system 300 functions as an image inspection device.

[0028] In this embodiment, at least the controller control unit 321, reference image generation control unit 322, and communication control unit 325 in the print controller unit 320, and the reference image generation unit 380 constitute a first control unit 501. At least the image control CPU 311 in the control unit 310, and at least the printer control unit 331 in the image forming unit 330 constitute a second control unit 502. At least the scanner control unit 342 in the image reading unit 340, and at least the image inspection control unit 351 in the image inspection unit 350 constitute a third control unit 503.

[0029] The first control unit 501 controls the generation of a reference image used to inspect an image formed on paper, based on the acquired original image (image data). The second control unit 502 controls the formation of an image on paper, based on the acquired original image. The third control unit 503 controls the execution of inspection of the image formed on paper, based on the reference image. The first control unit 501, the second control unit 502, and the third control unit 503 each have a CPU (Central Processing Unit), and at least one of the control units operates independently of the other control units. Therefore, at least one of the steps of generating the reference image, forming the inspection image, and inspecting the inspection image can be executed in parallel with the other steps.

[0030] <Configuration of control unit 310> The control unit 310 includes an image control CPU 311, a DRAM (Dynamic Random Access Memory) control IC 312, a memory 313, an image memory (DRAM) 314, a compression / decompression IC 315, a read processing unit 316, a write processing unit 317, a storage unit 318, and the like.

[0031] Image control CPU 311 loads various programs stored in storage unit 318 into memory 313, and controls the overall operation of image forming system 300 in cooperation with the loaded programs.

[0032] The reading processing unit 316 performs various processes, such as analog processing, A / D conversion processing, and shading processing, on the analog image signal output from the scanner 341 of the image reading unit 340 to generate digital image (read image) data. The generated digital image data is output to the compression / decompression IC 315 by the DRAM control IC 312. The compression / decompression IC 315 performs compression processing on the digital image data and decompression processing on the compressed digital image data under the control of the DRAM control IC 312. The DRAM control IC 312 also controls input / output to and from the image memory (DRAM) 314 for the compressed / decompressed digital image data.

[0033] The image memory 314 is made up of DRAM and has an internal compression memory and page memory area, and temporarily stores compressed image data, decompressed image data, and the like.

[0034] The write processing unit 317 outputs the decompressed digital image data to an exposure unit 332 of the image forming unit 330 .

[0035] <Configuration of print controller unit 320> The print controller unit 320 analyzes the print job received from the client terminal 200 via the communication line 400, and performs processes such as color conversion, screening, and rasterization to generate an original image in bitmap format. The generated original image is sent to the control unit 310. The print controller unit 320 functions as an original image acquisition unit.

[0036] The print controller unit 320 is configured with a controller control unit 321, a reference image generation control unit 322, a DRAM control IC 323, an image memory (DRAM) 324, a communication control unit 325, a communication I / F 326, etc. The controller control unit 321 comprehensively controls the operation of each unit of the print controller unit 320. The controller control unit 321 also receives print jobs from the client terminal 200, etc. via the communication I / F 326. The communication control unit 325 controls the communication I / F 326.

[0037] The received print job includes print data (mainly in PDL format) that is the source of the original image, and job information that describes print settings such as the type of paper to be used. The print controller unit 320 performs rasterization (RIP) processing, which converts the print data into bitmap data on a page-by-page basis based on the print settings. The RIP image after rasterization is temporarily stored in image memory 324. The RIP image in image memory 324 is temporarily stored in a compressed memory area within image memory 314 via compression / decompression IC 315 under the control of DRAM control IC 323 in print controller unit 320 and DRAM control IC 312 in control unit 310. During normal printing, the RIP image stored in the compressed memory area is decompressed by compression / decompression IC 315 and sent to image forming unit 330 as an original image via write processing unit 317, where it is printed.

[0038] The reference image generation control unit 322 outputs a reference image generation instruction to the reference image generation unit 380 (described later) to generate a reference image based on the document image at a predetermined generation timing. The predetermined generation timing may be, for example, when the inspection setting is on and the document image acquisition unit acquires the document image. The reference image generation unit 380 generates a reference image based on the reference image generation instruction.

[0039] Ideally, a scanned image generated by scanning an inspection image formed on paper would match the original image in terms of content. However, when scanning an inspection image formed on paper using a scanner, errors can occur in the scanned image compared to the original image due to various factors, such as variations in the paper transport path, misalignment of the scanner's reading position, color reproducibility, and differences in paper type. Furthermore, errors can also occur in the scanned image compared to the original image depending on the resolution of the scanner. Therefore, simply comparing the scanned image with the original image is likely to result in errors, and it is not realistic to inspect the inspection image by simply comparing the scanned image with the original image. Therefore, in this embodiment, various processes are performed on the original image regarding position, resolution, color, etc. to generate a reference image that can be compared with the scanned image, and the scanned image is then compared with the reference image. This allows for appropriate comparison with the scanned image, enabling accurate inspection of printed materials. Details of the reference image generation process will be described later. Although FIG. 2 illustrates an example in which the reference image generation control unit 322 is provided in the print controller unit 320, the reference image generation control unit 322 may be configured to be provided in the control unit 310.

[0040] <Configuration of Image Forming Unit 330> The image forming unit 330 forms (prints) an image on paper (recording medium) using an electrophotographic process, which includes charging, exposure, development, transfer, and fixing processes, in accordance with instructions from the control unit 310. In this embodiment, the image forming unit 330 forms an inspection image, which is inspected by the image inspection unit 350, on paper under image formation conditions set based on print settings. The image forming unit 330 includes a printer control unit 331 and an exposure unit 332. The printer control unit 331 is connected to the image control CPU 311 via serial communication and is controlled by the image control CPU 311. The printer control unit 331 drives the LD (laser diode) of the exposure unit 332 in response to a signal from the write processing unit 317, forming an electrostatic latent image corresponding to the original image on a photoreceptor (not shown). The toner image formed on the photoreceptor is developed through a development process and transferred onto paper supplied from the paper feed unit 370. The unfixed toner image on the paper is then fixed by applying heat and pressure. The paper on which the toner image has been fixed is transported to the image reading unit 340 .

[0041] The image forming unit 330 also includes a print sheet discharge device that separates and discharges (purges) paper (waste paper) on which an inspection image detected as abnormal by the image inspection unit 350 has been formed, from paper on which a normal inspection image has been formed.

[0042] <Configuration of image reading unit 340> The image reading unit 340 has a scanner 341 and a scanner control unit 342. The scanner 341 reads the paper (printed material) being transported along the transport path, for example, using a CCD (Charge Coupled Device) image sensor. The scanner control unit 342 controls the scanner to read the inspection image formed on the paper transported from the image forming unit 330 in accordance with a reading instruction from the control unit 310. The scanner control unit 342 outputs the read image obtained by reading the inspection image formed on the paper to the control unit 310.

[0043] <Configuration of image inspection unit 350> The image inspection unit 350 performs an image inspection based on the reference image. More specifically, the image inspection unit 350 acquires the reference image and the read image, and compares the reference image and the read image for each page, thereby inspecting the inspection image formed on the paper.

[0044] The image inspection unit 350 includes an image inspection control unit 351. The image inspection control unit 351 includes an image control CPU 311 or a CPU, RAM, ROM, and auxiliary storage device (not shown). The inspection function of the inspection image is realized by the CPU executing an image inspection program. The image inspection control unit 351, for example, calculates the difference (error) in pixel values ​​between the reference image and the scanned image for each page and determines the pass / fail of the inspection image based on the magnitude of the difference. The calculation of the difference can be performed for each page, each object, or each region. For example, when calculating the difference for each page, if the total value of the pixel differences within a page is less than a specified value, a "pass" inspection result is output; if the total value of the differences is equal to or greater than the specified value, a "fail" inspection result is output. Furthermore, when calculating the difference for each object or region, the system can be configured to output a "pass" or "fail" inspection result based on the total value of the pixel differences within the selected object or region.

[0045] If the inspection result of the inspection image is "good", the control unit 310 determines that the printed matter is a good product, and if the inspection result of the inspection image is "bad", the control unit 310 determines that the printed matter is a defective product.

[0046] <Configuration of operation display unit 360> The operation display unit 360 includes a touch panel display 361, an operation control unit 362, a numeric keypad as hard keys, a start button, a stop button, and the like. The touch panel display includes, for example, a touch sensor and an LCD (Liquid Crystal Display) located behind the touch sensor. The operation control unit 362 accepts input from the touch sensor and hard keys and transmits the input data to the control unit 310. The operation control unit 362 also receives output data from the control unit 310 and displays it on the LCD. The operation display unit 360 is used by the user to input various settings (e.g., inspection on / off and inspection level in the inspection settings) and instructions (e.g., an instruction to start printing). The operation display unit 360 is also used to output (display) the status of the image forming system 300, the inspection results of printed materials (good / bad), images of defective printed materials, etc.

[0047] <Configuration of Paper Feed Unit 370> The paper feed unit 370 includes at least one large-capacity paper tray, and supplies paper to the image forming unit 330 one sheet at a time.

[0048] <Configuration of Reference Image Generator 380> Reference image generating unit 380 generates a reference image based on the original image acquired by the original image acquiring unit, and outputs the generated reference image to control unit 310. Reference image generating unit 380 can be realized by a CPU (not shown) separate from image control CPU 311 executing an image inspection program. This allows the generation of a reference image and the formation and inspection of an inspection image to be performed in parallel.

[0049] In the past, the same CPU was configured to generate the reference image and form and inspect the inspection image. Therefore, the CPU would form and inspect the inspection image after completing the generation of the reference image for each page, so it was not possible to generate the reference image and form and inspect the inspection image in parallel. In this embodiment, the generation of the reference image and the formation and inspection of the inspection image are configured to be performed by separate CPUs, so the generation of the reference image and the formation and inspection of the inspection image can be performed in parallel.

[0050] Furthermore, the CPU processing load (processing time) for generating the reference image may increase or decrease depending on the complexity of the original image, the presence or absence of variable printing, etc. For example, if the original image is complex, the CPU processing load for generating the reference image may increase significantly. By having a CPU separate from image control CPU 311 take charge of generating the reference image, the processing load on image control CPU 311 can be reduced.

[0051] <Configuration of storage device 390> The storage device 390 stores the reference image generated by the reference image generating unit 380. When reprinting an original image, the control unit 310 uses the reference image stored in the storage device 390, eliminating the need to generate the reference image again. This eliminates the need to generate the reference image again.

[0052] <Outline of Control Operations of Control Unit 310 and Print Controller Unit 320> FIG. 3 is a block diagram for explaining an outline of the control operations of the control unit 310 and the print controller unit 320 shown in FIG.

[0053] First, the control unit 310 receives an original image and job information from the original image acquisition unit (print controller unit 320) ((1) Image input). The original image is an RIP image obtained by rasterizing print data.

[0054] When the reference image generation unit 380 receives a reference image generation instruction from the reference image generation control unit 322 ((2)-1 reference image generation instruction), it generates a reference image based on the document image acquired by the document image acquisition unit and outputs it to the control unit 310. The control unit 310 stores the reference image in the page memory 1.

[0055] As described above, the reference image generation unit 380 generates a reference image by performing various processes on the document image regarding position, resolution, color, etc. For example, the reference image generation unit 380 can extract position information of content portions from the document image and add or embed the position information in the reference image so that the content portions (contents) of the reference image and the scanned image can be compared. That is, the reference image generated by the reference image generation unit 380 includes alignment information for aligning the reference image and the scanned image when performing image inspection based on the reference image. The alignment information includes image contour information and edge information. The reference image generated by the reference image generation unit 380 also includes area information regarding the inspection area and the non-inspection area used when performing image inspection based on the reference image. Furthermore, the reference image generation unit 380 can generate a reference image by adjusting the resolution of the document image to match the resolution of the scanner of the image reading unit 340. Furthermore, the reference image generating unit 380 can generate a reference image by converting the color space of the original image so that it matches the color space (for example, RGB) used by the scanner of the image reading unit 340 .

[0056] Furthermore, when the control unit 310 receives an original image from the original image acquisition unit, it instructs the image forming unit 330 to form an image and outputs the original image stored in the page memory 1 to the image forming unit 330 ((2)-2 Image output). In this embodiment, the image forming unit 330 forms an inspection image on paper based on the original image. The generation of the reference image by the reference image generation unit 380 and the formation of the inspection image by the image forming unit 330 are performed in parallel.

[0057] When the reference image generation unit 380 completes the generation of the reference image, it notifies the reference image generation control unit 322 of the completion of reference image generation ((3)-1 Reference image generation completed). Furthermore, when the image forming unit 330 completes image formation on paper, it notifies the control unit 310 of the completion of output ((3)-2 Output completed). The storage device 390 saves the generated reference image ((4)-1 Save reference image).

[0058] Furthermore, upon receiving notification of output completion, the control unit 310 immediately outputs an image reading instruction to the image reading unit 340 ((4)-2 Image reading instruction). The image reading unit 340 reads the paper on which the inspection image is formed, and outputs the read image of the paper to the control unit 310. The control unit 310 stores the read image in the page memory 2. Upon completion of reading the paper, the image reading unit 340 notifies the completion of image reading ((5)-2 Image reading completion).

[0059] Upon receiving notification that image reading is complete, the control unit 310 outputs an image inspection instruction to the image inspection unit 350 ((6)-2 Image inspection instruction). The image inspection unit 350 obtains the reference image and the read image from the page memory 1 and the page memory 2, respectively, and inspects the inspection image by comparing the reference image with the read image. The image inspection unit 350 then outputs the inspection result of the inspection image to the control unit 310 ((7)-2 Image inspection result).

[0060] In response to an instruction from the user, the control unit 310 controls the operation display unit 360 or the display of the client terminal 200 to display the inspection result (good / bad) of the printed matter based on the inspection result of the inspection image.

[0061] <Image Inspection Method Using Image Forming System 300> Fig. 4 is a flowchart illustrating the processing procedure of an image inspection method by image forming system 300 shown in Fig. 1. Fig. 5 is a subroutine flowchart illustrating the details of inspection of an inspection image in the flowchart shown in Fig. 4. The processing shown in Figs. 4 and 5 is realized by image control CPU 311 executing an image inspection program. Fig. 6 is a schematic diagram showing each process of obtaining an original image, generating a reference image, forming an inspection image, and inspecting the inspection image in chronological order.

[0062] As shown in FIG. 4, first, the control unit 310 acquires an original image (step S101). The control unit 310 receives the original image (RIP image) one page at a time from the original image acquisition unit, starting with the first page and ending with the nth page. For example, FIG. 6 illustrates a case in which the original images are received in order from the first page to the eighth page. Note that in this figure and in FIG. 7, "1P" represents the first page (the same applies to "2P" and so on). Furthermore, "print preparation" in forming the test image includes initial settings and preparations of each unit (for example, warming up the fixing unit) according to the image formation conditions in the image forming unit 330.

[0063] Next, the control unit 310 stores the document images (step S102). When a print job is started, the control unit 310 stores the document images acquired from the document image acquisition unit in the page memory 1 page by page.

[0064] Next, reference image generation control unit 322 controls the generation of a reference image to be used in inspecting the inspection image. Reference image generation unit 380 generates a reference image in accordance with an instruction from reference image generation control unit 322 (step S103). For example, when the first page of the original image is acquired and stored in page memory 1, reference image generation control unit 322 controls reference image generation unit 380 to generate a reference image based on the first page of the original image. Reference image generation unit 380 generates a reference image based on the first page of the original image. A reference image is similarly generated for the second page of the original image.

[0065] Next, the storage device 390 stores the reference image generated by the reference image generation unit 380 (step S104). For example, the storage device 390 stores the first and second pages of the document image. In this embodiment, as shown in FIG. 6, in parallel with the processes of steps S103 and S104, the control unit 310 controls the image forming unit 330 to form an inspection image on paper based on the document image and job information received from the document image acquisition unit. For example, the control unit 310 performs printing preparation and controls the image forming unit 330 to form an inspection image on paper for the first page of the document image. The image forming unit 330 forms an inspection image on paper for the first page of the document image in accordance with the instructions of the control unit 310 (step S105). After the inspection image for the first page of the document image is formed, an inspection image for the second page of the document image is similarly formed on paper.

[0066] Next, the image inspection unit 350 determines whether a reference image has been generated for each page of the acquired document image (step S106). If a reference image has been generated (step S106: YES), the image inspection unit 350 inspects the inspection image formed by the image forming unit 330 (step S107). On the other hand, if a reference image has not been generated (step S106: NO), the image inspection unit 350 waits until a reference image is generated. For example, if a reference image of the same document image (first page) as the document image (first page) that is the basis of the inspection image inspected in step S107 has not been generated, the image inspection unit 350 waits until a reference image of this document image (first page) is generated.

[0067] 6, the generation of a reference image by reference image generation unit 380 and the formation and inspection of an inspection image by image formation unit 330 are performed in parallel. This enables image formation system 300 to further reduce the time required for processing from the generation of a reference image to image inspection compared to conventional techniques.

[0068] [Parallel generation of reference image and formation of test image on paper] For example, in the example shown in the figure, the generation of reference images for the first page (1P) and the second page (2P) and printing preparation are performed in parallel, and the generation of the reference image for the third page (3P) and the formation of the inspection image for the first page (1P) (first half) are performed in parallel. Then, the generation of the reference image for the fourth page (4P) and the formation of the inspection image for the first page (1P) (second half) are performed in parallel. Note that in the figure, the generation of the reference image for the third page (3P) and the formation of the inspection image for the first page (1P) are shown to start simultaneously, but this is not limited to this. The formation of the inspection image for the first page (1P) can start at an appropriate time after the completion of printing preparation, and the generation of the reference image for the third page (3P) can start at an appropriate time after the generation of the reference image for the second page (2P). The start timing of the generation of the reference image and the generation of the inspection image is the same for subsequent pages.

[0069] [Generating a reference image, forming a test image on paper, and inspecting the test image in parallel] After that, the generation of the reference image of the fifth page (5P), the formation of the inspection image of the second page (2P), and the inspection of the inspection image of the first page are executed in parallel.

[0070] As shown in FIG. 5, in the process of inspecting the inspection image, the inspection image formed on paper is read by the image reading unit 340 (step S201), and the inspection image is inspected by the image inspection unit 350 by comparing the read image with a reference image (step S202).

[0071] The control unit 310 repeats the processes of steps S101 to S107 until inspection of the inspection images for all pages (from the first page to the final n-th page) is completed (step S108).

[0072] In this manner, in this embodiment, a reference image is generated based on the reception of the original image (starting from the reception of the original image), and an inspection image is formed on paper when printing preparations are complete, and the inspection image is then inspected. In this embodiment, the generation of the reference image and the formation and inspection of the inspection image are performed in parallel, thereby reducing the time required for processing from the generation of the reference image to the image inspection. As a result, productivity is improved in the series of processes leading up to the creation of a printout without any defects.

[0073] <print job> As described above, when image forming system 300 receives a print job and the inspection setting in the job information is inspection on, it generates a reference image and forms an inspection image in parallel. Control unit 310 and print controller unit 320 control reference image generation unit 380 and inspection image formation unit 330 to be performed in parallel using one (same) print job.

[0074] Alternatively, the image forming system 300 may generate a reference image and form and inspect an inspection image using separate print jobs. The control unit 310 and the print controller unit 320 control the reference image generation process (reference image generation job) and the inspection process (inspection job) to be executed in parallel. Here, the reference image generation process includes the generation of a reference image by the reference image generation unit 380. The inspection process includes the formation of an inspection image on paper by the image forming unit 330 and the image inspection unit 350 inspecting the scanned image generated by scanning the paper on which the inspection image is formed. For example, the reference image generation process may be executed by a CPU other than the image control CPU 311, and the inspection process may be executed by the image control CPU 311. Alternatively, if the control unit 310 has a multi-core CPU, the reference image generation process and the inspection process may be assigned to separate cores, and these cores may execute the reference image generation process and the inspection process in parallel.

[0075] <Recovery Print> FIG. 7 is a schematic diagram showing, in chronological order, the processes of acquiring an original image, generating a reference image, forming an inspection image, and inspecting the inspection image when recovery printing is performed.

[0076] The control unit 310 and the image forming unit 330 function as a recovery printing unit. If an abnormality is detected in the test image, the recovery printing unit performs reprinting (recovery printing) from the page of the original image corresponding to the page of the test image where the abnormality was detected. In this embodiment, the control unit 310 determines that an abnormality has been detected in the test image when the test image is found to be defective as a result of inspection by the image inspection unit 350. The control unit 310 purges the paper on which the test image where the abnormality was detected has been formed as waste paper to the outside of the image forming system 300.

[0077] Generally, the more complex the original image, the longer it takes for the reference image generation unit 380 to generate the reference image. For example, FIG. 7 illustrates an example in which the second page of an original image is complex, and therefore the generation of the second page of the reference image takes time. The recovery printing unit performs recovery printing if the generation of the reference image is not completed before the inspection of the corresponding test image. For example, in the example shown in FIG. 7, the generation of the second page of the reference image is not completed even after the formation of the second page of the test image. Therefore, the recovery printing unit waits for the generation of the reference image to be completed before performing recovery printing of the second page of the original image (forming the second page of the test image). The control unit 310 purges the paper for the second page of the test image that has already been printed. This prevents paper on which an uninspected test image has been formed from being mixed with paper on which a normal test image has been formed.

[0078] Furthermore, during recovery printing, the image inspection unit 350 can perform image inspection using the reference image stored in the storage device 390. This eliminates the need for the reference image generation unit 380 to generate the reference image again, thereby saving the time required to generate the reference image.

[0079] Furthermore, when performing recovery printing, the document image stored in page memory 1 in step S102 of FIG. 4 can be configured to be stored in storage device 390. By using the document image stored in storage device 390, the processes of steps S101 and S102, as well as the processes of generating and storing a reference image (steps S103 and S104), become unnecessary. Therefore, control unit 310 and print controller unit 320 control the print job so that only the process of forming an inspection image and inspecting it is executed. This reduces the time required from the start of a print job to the completion of inspection of the printed matter. As a result, productivity of printed matter is improved.

[0080] <Effects of the First Embodiment> The image inspection device, the image inspection method, and the image inspection program according to the first embodiment described above can achieve the following effects.

[0081] The first control unit 501, the second control unit 502, and the third control unit 503 each have a CPU, and at least one of the control units operates independently of the other control units. Therefore, at least one of the steps of generating a reference image, forming an inspection image, and inspecting the reference image can be executed in parallel with the other steps. As a result, the time required for processing from generating a reference image to inspecting the image can be shortened.

[0082] (Second embodiment) In the first embodiment, the first to third control units 501 to 503 are configured by separate CPUs. In the second embodiment, the first to third control units 501 to 503 are configured by a multi-core CPU, with a core assigned to each control unit. In the following description, to avoid duplication, descriptions of the same configuration as in the first embodiment will be omitted or simplified.

[0083] 8 is a schematic block diagram illustrating the configuration of an image forming system according to the second embodiment. The diagram shows that, in the initial state, cores 0, 1, 2, and 3 of one multi-core CPU are assigned to first to third control units 501 to 503, respectively. While the diagram illustrates a four-core CPU, the number of cores in the multi-core CPU of this embodiment is not limited to four, and may be six or more.

[0084] <Core allocation> The number of cores assigned to each of the first to third control units 501 to 503 can be changed. In this embodiment, for example, the number of cores assigned to each control unit can be changed based on the inspection conditions for inspecting the inspection image. The inspection conditions include at least one of the number of inspection exclusion areas, the number of variable areas, the amount of information in the variable areas, and the inspection level. The inspection exclusion areas are areas that are excluded from abnormality detection during inspection of the inspection image. The variable areas are areas where variable printing is performed. Variable printing refers to printing in which the printed content of each sheet can be partially replaced as needed. The inspection level (inspection level) indicates the degree of strictness when performing inspection and can be selected from multiple levels, such as "mild," "normal," and "strict." The user can set the inspection level in the inspection settings of the print settings. The user can also change the inspection level via the operation and display unit 360 even after inspection of the inspection image has begun.

[0085] The processing load (processing time) of the core in generating the reference image may increase or decrease depending on factors such as the complexity of the original image and whether or not variable printing is used. For example, if the original image is complex, the processing load in generating the reference image may increase significantly. The processing load of the core in image processing for forming the inspection image may also increase or decrease depending on factors such as the complexity of the original image and whether or not variable printing is used. However, in forming the inspection image, the time required for paper transport and fixing is relatively longer than the time required for image processing. For this reason, when forming the inspection image, if averaged over time, the processing load of the core for image processing is often not large. The processing load of the core in inspecting the inspection image may also increase or decrease depending on the number of inspection exclusion areas, the number of variable areas, the amount of information in the variable areas, and the inspection level.

[0086] For example, the greater the number of non-inspection regions, the smaller the amount of processing that cores 2 and 3 must perform in inspecting the inspection image, and therefore the number of cores allocated to inspecting the inspection image by the third control unit 503 can be reduced. Therefore, the number of cores allocated to the first control unit 501 can be increased by the amount of the reduction in the number of cores required for inspecting the inspection image. For example, when the number of non-inspection regions is large, the allocation can be changed so that core 3, which was allocated to the third control unit 503, is allocated to the first control unit 501.

[0087] Furthermore, the greater the number of variable regions and the amount of information in the variable regions, the greater the processing load for generating the reference image, so it is preferable to increase the number of cores allocated to the first control unit 501.

[0088] Furthermore, when the inspection level is "strict," the processing load for inspecting the inspection image is large, so it is preferable to maintain or increase the number of cores allocated to the third control unit 503. On the other hand, when the inspection level is "gentle," the processing load for inspecting the inspection image is small, so the number of cores allocated to inspecting the inspection image can be reduced.

[0089] <Core allocation priority> As described above, while there is a high possibility that the processing load of a core will increase or decrease for generating a reference image and inspecting an inspection image, there is a low possibility that the processing load of a core will increase or decrease for forming an inspection image. Therefore, in this embodiment, the first control unit 501 and the third control unit 503 are assigned cores with priority over the second control unit 502. For example, more cores may be assigned to the first control unit 501 and the third control unit 503 than to the second control unit 502. Furthermore, when the cores of the first control unit 501 or the third control unit 503 and the cores of the second control unit 502 have approximately the same usage rate, more cores may be assigned to the first control unit 501 or the third control unit 503.

[0090] Furthermore, for example, if the original image is a complex image, the processing load on the cores for generating the reference image may increase significantly. Furthermore, generating a reference image often imposes a higher processing load than inspecting an inspection image. Therefore, cores are allocated to the first control unit 501 with priority over the third control unit 503. For example, more cores may be allocated to the first control unit 501 than to the third control unit 503. Furthermore, if the cores of the first control unit 501 and the cores of the third control unit 503 have approximately the same usage rate, more cores may be allocated to the first control unit 501.

[0091] In this way, cores are allocated with priority in the order of the first control unit 501, the third control unit 503, and the second control unit 502.

[0092] <Changing the core allocation ratio based on the change in inspection level> If the inspection level is changed during inspection of an inspection image, the ratio of the number of cores allocated to the first control unit 501 and the third control unit 503 is changed based on the change in inspection level. For example, the ratio of the number of cores of the first control unit 501 to the number of cores of the third control unit 503 is changed according to the changed inspection level. More specifically, if the inspection level is "strict," the ratio of core allocation is changed so that the ratio of the number of cores of the first control unit 501 to the number of cores of the third control unit 503 becomes smaller. On the other hand, if the inspection level is "lenient," the ratio of core allocation is changed so that the ratio of the number of cores of the first control unit 501 to the number of cores of the third control unit 503 becomes larger.

[0093] In addition, if the processing load on a core for generating a reference image is greater than the processing load on a core for inspecting an inspection image, the core allocation ratio is changed so that the ratio of the number of cores in the first control unit 501 to the number of cores in the third control unit 503 becomes larger.

[0094] <Effects of the Second Embodiment> The image inspection device, the image inspection method, and the image inspection program according to the second embodiment described above can achieve the following effects.

[0095] The first control unit 501, the second control unit 502, and the third control unit 503 are configured in a multi-core CPU with each control unit assigned a core. With this configuration, at least one of the control units operates independently of the other control units. Therefore, at least one of the steps of generating a reference image, forming an inspection image, and inspecting the reference image can be executed in parallel with the other steps. As a result, the time required for processing from generating a reference image to inspecting the image can be reduced.

[0096] As described above, the image inspection device, the image inspection method, and the image inspection program have been described in the embodiments. However, it goes without saying that those skilled in the art can appropriately add, modify, and omit the present invention within the scope of the technical concept thereof.

[0097] For example, in the above-described embodiment, a case where an original image is generated based on a print job has been described, but the present invention is not limited to such a case. The image forming unit 330 may be configured to have an image reading device 333 (see FIG. 1) that reads an original prepared by a user, and to generate an original image based on an image generated by reading the original using the image reading device 333. The image reading device 333, for example, uses a scanner to read an original transported to a predetermined reading position by an automatic document feeder, and generates image data.

[0098] The image inspection program may be provided on a computer-readable recording medium such as a USB memory, flexible disk, or CD-ROM, or may be provided online via a network such as the Internet. In this case, the program recorded on the computer-readable recording medium is typically transferred and stored in memory or storage. The inspection program may be provided as standalone application software, or may be incorporated into the software of each device as a function of the server.

[0099] In addition, in the embodiment, part or all of the processing executed by the inspection program may be replaced with hardware such as a circuit. [Explanation of symbols]

[0100] 100 printing systems, 200 client terminals, 300 Image forming system, 310 control section, 311 Image control CPU, 312 DRAM control IC, 313 Memory, 314 image memory (DRAM), 315 Compression / Expansion IC, 316 reading processing section, 317 write processing unit, 318 Memory section, 320 Print controller section, 321 Controller control section, 322 Reference image generation control unit, 323 DRAM control IC, 324 image memory (DRAM), 325 Communications Control Section, 326 communication I / F, 330 Image forming unit, 331 Printer control unit, 332 Exposure section, 333 Image reading device, 340 Image reading unit, 341 scanner, 342 scanner control unit, 350 Imaging Department, 351 Image inspection control unit, 360 operation display section, 361 LCD / touch sensor, 362 Operation control section, 370 Paper feed section, 380 Reference image generation unit, 390 storage device, 400 communication lines, 501 First control section, 502 second control section, 503 Third Control Section.

Claims

1. a first control unit that controls generation of a reference image used for inspecting an image formed on a recording medium based on the acquired image data; a second control unit that controls the formation of the image on the recording medium based on the acquired image data; a third control unit that controls execution of inspection of the image formed on the recording medium based on the reference image, The image inspection device, wherein the first control unit, the second control unit, and the third control unit are configured by assigning a core to each control unit in a CPU.

2. The image inspection device according to claim 1 , wherein the number of cores allocated to each control unit is changed based on the inspection conditions of the inspection.

3. The image inspection device according to claim 2 , wherein the inspection conditions include at least one of the number of inspection exclusion areas, the number of variable areas, the amount of information in the variable areas, and an inspection level.

4. The image inspection device according to claim 1 , wherein cores are allocated to the first control unit and the third control unit with priority over the second control unit.

5. The image inspection device according to claim 1 , wherein cores are allocated to the first control unit with higher priority than to the third control unit.

6. 2. The image inspection device according to claim 1, wherein, when an inspection level is changed during inspection of the image, a ratio of cores allocated to the first control unit and the third control unit is changed based on the change in the inspection level.

7. 2. The image inspection device according to claim 1, wherein the generation of the reference image and the formation of the image on the recording medium are performed in parallel.

8. A reference image generation control unit that controls generation of a reference image used for inspecting an image formed on a recording medium based on the acquired image data; an inspection control unit that controls execution of inspection of the image formed on the recording medium based on the reference image, In the image inspection device, the reference image generation control unit and the inspection control unit are configured by allocating a core to each control unit in a CPU.

9. An image inspection device as described in claim 8, which changes the number of cores assigned to each control unit based on the inspection conditions of the inspection.

10. An image inspection device as described in Claim 9, wherein the inspection conditions include at least one of the number of inspection exclusion areas, the number of variable areas, the amount of information in the variable areas, and the inspection level.

11. An image inspection device as described in claim 8, in which cores are assigned to the reference image generation control unit in priority to the inspection control unit.

12. An image inspection device as described in Claim 8, which, when the inspection level is changed during inspection of the image, changes the proportion of cores allocated to the reference image generation control unit and the inspection control unit based on the change in the inspection level.

13. 1. An image inspection method for inspecting an image formed on a recording medium based on a print job, comprising: a first control step in which a first control unit controls generation of a reference image used for inspecting an image formed on a recording medium based on the acquired image data; a second control step in which a second control unit controls image formation on a recording medium based on the acquired print job; a third control step in which a third control unit controls an inspection of an image formed on a recording medium based on the acquired print job, An image inspection method, characterized in that the first control unit, the second control unit, and the third control unit are configured in a CPU with a core assigned to each control unit.

14. An image inspection method for inspecting an image formed on a recording medium based on a print job, comprising: a reference image generation control step in which a reference image generation control unit controls generation of a reference image used for inspecting an image formed on a recording medium based on the acquired image data; an inspection control step in which an inspection control unit controls execution of an inspection of the image formed on the recording medium based on the reference image, The image inspection method, wherein the reference image generation control unit and the inspection control unit are configured by allocating a core to each control unit in a CPU.

15. An image inspection method as described in claim 14, wherein the number of cores assigned to each control unit is changed based on the inspection conditions of the inspection.

16. An image inspection method as described in Claim 15, wherein the inspection conditions include at least one of the number of inspection exclusion areas, the number of variable areas, the amount of information in the variable areas, and the inspection level.

17. An image inspection method as described in claim 14, wherein a core is assigned to the reference image generation control unit in preference to the inspection control unit.

18. An image inspection method as described in Claim 14, wherein when the inspection level is changed during inspection of the image, the proportion of cores allocated to the reference image generation control unit and the inspection control unit is changed based on the change in the inspection level.

19. An image inspection program for inspecting an image formed on a recording medium based on a print job, a first control procedure in which a first control unit controls generation of a reference image based on the received print job; a second control procedure in which a second control unit controls image formation on a recording medium based on the received print job; a third control procedure in which a third control unit controls an inspection of an image formed on a recording medium based on the received print job, An image inspection program characterized in that the first control unit, the second control unit, and the third control unit are configured in a CPU by allocating a core to each control unit.

20. An image inspection program for inspecting an image formed on a recording medium based on a print job, comprising: a reference image generation control procedure in which a reference image generation control unit controls generation of a reference image used for inspecting an image formed on a recording medium based on the received image data; an inspection control procedure in which an inspection control unit controls execution of an inspection of an image formed on the recording medium based on the reference image; The reference image generation control unit and the inspection control unit are configured in a CPU with a core assigned to each control unit.

21. An image inspection program as described in claim 20, which changes the number of cores assigned to each control unit based on the inspection conditions of the inspection.

22. An image inspection program as described in Claim 21, wherein the inspection conditions include at least one of the number of inspection exclusion areas, the number of variable areas, the amount of information in the variable areas, and the inspection level.

23. An image inspection program as described in claim 20, which allocates a core to the reference image generation control unit in priority to the inspection control unit.

24. An image inspection program as described in Claim 20, which, when the inspection level is changed during inspection of the image, changes the proportion of cores allocated to the reference image generation control unit and the inspection control unit based on the change in the inspection level.

Images