Plate inspection system, plate inspection method, and program

Abstract

To provide a plate inspection system, a plate inspection method, and a program that eliminate the need of the original of an appearance sample, and can execute plate inspection from scanned data obtained by reading the appearance sample with a scanner and the profile of the scanner.SOLUTION: The present invention comprises: creation means that performs color conversion of scanned data of a RGB appearance sample into a L*a*b* value, and subsequently creates a master image for executing inspection of a plate of an image printed by an image forming apparatus on the basis of the scanned data of the appearance sample; information storage means that can store the scanned data of the appearance sample and the master image in connection to each other; and notification means that notifies a user of the result of the execution of inspection of the plate of the image printed by the image forming apparatus on the basis of the scanned data of the appearance sample and the master image stored in the information storage means.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a plate inspection system, a plate inspection method, and a program. [Background technology]

[0002] 2. Description of the Related Art There is an image inspection technique that compares original image data, which is image data of an original print source, with image data obtained by scanning a printout of the original image data to inspect whether the printout is normal.

[0003] Patent Document 1 is an invention related to a digital plate inspection technology before plate making in offset printing, and discloses a technology to carry out plate inspection by comparing manuscript image data with scanned data of a format sample read by a scanner in bitmap format. This makes it possible to reduce the workload and the risk of overlooking differences compared to the conventional method of outputting after matching the editing work environment of DTP (Desk Top Publishing) with that of the client, and visually inspecting the output on paper or after converting it to digital. Summary of the Invention [Problem to be solved by the invention]

[0004] However, the above technology directly compares the original image data with the scanned data of the presentation sample, so there is no problem if the presentation sample is submitted on paper and can be read by a scanner whose characteristics are known. However, if the presentation sample is submitted as scanned data, accurate inspection cannot be performed because the scanner characteristics are unknown and the actual color of the presentation sample cannot be determined.

[0005] In addition, the above technology is designed for plate inspection before plate making in offset printing, and the actual printing is carried out using that plate, but in digital printing, the image is formed directly from the image data, so plate inspection of the output is necessary in the image forming device that performs the actual printing.

[0006] The present invention has been made in consideration of the above, and aims to provide a plate inspection system, plate inspection method, and program that eliminate the need for an original presentation sample and can perform plate inspection using scan data obtained by reading the presentation sample with a scanner and the scanner profile. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems and achieve the object, the present invention comprises a generation means for color-converting RGB scan data of a presentation sample to L*a*b* values ​​and then generating a master image for performing plate inspection of an image printed by an image forming device based on the scan data of the presentation sample, an information storage means for linking and saving the scan data of the presentation sample and the master image, and a notification means for notifying the results of plate inspection of an image printed by the image forming device based on the scan data of the presentation sample and the master image stored in the information storage means. Effect of the Invention

[0008] According to the present invention, an original presentation sample is not required, and plate inspection can be performed based on scan data obtained by reading the presentation sample with a scanner and a scanner profile. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram for explaining an example of the characteristics of the plate inspection system according to the present embodiment. [Diagram 2] FIG. 2 is a diagram showing an example of the configuration of the plate inspection system according to the present embodiment. [Diagram 3] FIG. 3 is a diagram showing an example of the functional configuration of an image forming apparatus included in the plate inspection system according to the present embodiment. [Figure 4] FIG. 4 is a flowchart showing an example of the flow of plate inspection in the plate inspection system according to this embodiment. [Diagram 5]FIG. 5 is a flowchart showing an example of the flow of a process for calculating CMYK correction amounts in the plate inspection system according to the present embodiment. [Figure 6] FIG. 6 is a diagram for explaining an example of the process of calculating the CMYK correction amounts in the plate inspection system according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a plate inspection system, a plate inspection method, and a program will be described in detail with reference to the accompanying drawings.

[0011] Fig. 1 is a diagram for explaining an example of the characteristics of the plate inspection system according to the present embodiment. The plate inspection system according to the present embodiment is characterized in that even if the original of the presentation sample is not at hand, the plate inspection can be performed if there is scan data obtained by scanning the presentation sample with a scanner and a profile of the scanner. Specifically, the plate inspection system generates a master image to be compared for inspecting defects from the scanned image of the output (printed material) by converting the scan data of the presentation sample (presentation sample data) represented by RGB values ​​into L*a*b* values ​​that are not device-dependent, as shown in Fig. 1, and then reconverting the converted data into RGB values ​​in accordance with the characteristics of the scanner (scanner B) of the image forming device that performs the plate inspection and the actual printing.

[0012] In digital printing, which forms an image from original image data, by comparing the master image with scan data (actual print scan data) obtained by reading a printout of the original image data, it is possible to detect not only printing defects, but also problems such as garbled characters and content errors that can occur in the RIP (Raster Image Processor) process, as well as differences in color from the format sample.

[0013] Fig. 2 is a diagram showing an example of the configuration of a plate inspection system according to the present embodiment. As shown in Fig. 2, the plate inspection system according to the present embodiment includes an image forming apparatus 1 and a PC (Personal Computer) 2 for executing printing on the image forming apparatus 1.

[0014] Fig. 3 is a diagram showing an example of the functional configuration of an image forming device of a plate inspection system according to this embodiment. In this embodiment, image forming device 1 is an example of an image forming device having a plate inspection function for a printed image. Specifically, as shown in Fig. 3, image forming device 1 includes a data processing unit 100, an inspection unit 200, and a display unit 300. Data processing unit 100 includes a master image generating unit 101, an image data registration unit 102, a read image generating unit 103, and a correction amount calculating unit 104.

[0015] The master image generating unit 101 is an example of a generating means that converts the color of the RGB sample scan data (sample data) into L*a*b* values, and then generates a master image based on the sample data for plate inspection of an image printed by the image forming apparatus 1. In this embodiment, the master image generating unit 101 converts the color of the sample data into device-independent L*a*b* values. Here, the L*a*b* values ​​are those of Japanese JIS (JIS Z 8781-4).

[0016] The image data registration unit 102 is an example of an information storage unit capable of storing the layout sample data and the master image in association with each other. The read image generation unit 103 generates an RGB read image of the printed image.

[0017] The correction amount calculation unit 104 is an example of a calculation means for calculating the amount of color conversion of RGB output for CMYK input for each printing condition. The correction amount calculation unit 104 is also an example of a reflection means for calculating the amount of CMYK correction (CMYK correction amount) for matching the color of the read image to the master image based on the amount of color conversion corresponding to the printing conditions of the image forming apparatus 1 and the difference in color between the RGB master image and the RGB read image of the printed image, and reflecting the amount of CMYK correction in the image forming apparatus 1. As a result, when the color is NG in the plate inspection, the CMYK correction amount for matching the color is calculated from the result of comparing the scan data of the presentation sample with the scan data of the actual printed matter, and the amount of CMYK correction is fed back to the image forming apparatus 1, making it possible to perform automatic color adjustment and shorten the time required for adjustment.

[0018] The inspection unit 200 is an example of an inspection means that performs inspection (plate inspection) for printing defects, color, and the like by comparing two images (master image and read image) obtained by the master image generation unit 101 and the read image generation unit 103 of the printed matter. The inspection unit 200 is also an example of a notification means that performs plate inspection of an image (read image) printed by the image forming apparatus 1 based on the appearance sample data and the master image stored in the image data registration unit 102, and notifies the result of the inspection. This makes the original appearance sample unnecessary, and makes it possible to perform plate inspection using scan data obtained by reading the appearance sample with a scanner and a scanner profile.

[0019] In this embodiment, the inspection unit 200 includes a RIP process defect inspection unit 201, a print defect inspection unit 202, and a color inspection unit 203. The RIP process defect inspection unit 201 compares a master image with a read image to inspect for defects in the RIP process such as garbled characters. The print defect inspection unit 202 compares a master image with a read image to inspect for print defects such as dots and streaks. The color inspection unit 203 compares a master image with a read image to inspect for differences in color from a format sample.

[0020] Next, an example of the operation when inspecting the appearance sample data when carrying out the actual printing will be described with reference to Fig. 4. The image forming device 1 (configuration B shown in Fig. 1) that carries out the actual printing is equipped with a scanner (scanner B in Fig. 1) to enable image inspection. The master image is RGB image data that has the same contents and colors as the appearance sample.

[0021] 4 is a flow chart showing an example of the flow of plate inspection in the plate inspection system according to the present embodiment. First, when plate inspection starts, the master image generating unit 101 selects whether or not to generate a master image (step S101). If a master image corresponding to the layout sample data to be used has already been generated, plate inspection can be performed using the generated master image, and if a master image does not exist, a new master image is generated. If a master image is to be generated (step S101: No), the master image generating unit 101 selects the layout sample data to be used for plate inspection (step S102). The layout sample data is sent to the image data registration unit 102 and then to the master image generating unit 101.

[0022] Further, PC2 selects the profile of the configuration A (scanner A in FIG. 1) used to generate the presentation sample data (step S103), selects the profile of the scanner B used to read the output of the machine (image forming device 1) that performs the actual printing (step S104), and sends the selected profile to the master image generating unit 101. The scanner profile includes information on the correspondence between the colors before and after reading by the scanner. Next, the master image generating unit 101 performs color space conversion from RGB to L*a*b* values ​​for the presentation sample data (step S105). At that time, the master image generating unit 101 uses the profile of the scanner A selected in step S103 to remove the scanner characteristics of the scanner A from the presentation sample data and obtain L*a*b* values ​​that correspond to the colors of the actual presentation sample.

[0023] Furthermore, the master image generating unit 101 uses the profile of scanner B selected in step S104 to further convert the appearance sample data obtained in step S105 from L*a*b* values ​​to RGB color space, thereby generating an RGB master image with the characteristics of scanner B added to the appearance sample (step S106). Since the scanned image to be compared with the master image during plate inspection contains the scanner characteristics of scanner B, generating the master image as an image containing the characteristics of scanner B in this way makes it possible to align the scanner characteristic conditions and directly compare differences in color tone due to the output from image forming apparatus 1.

[0024] If the scanner profile and the actual scanner characteristics differ, it will be impossible to accurately obtain the color of the presentation sample, and it will be impossible to compare the master image and the scanned image by matching the characteristics of scanner B. Therefore, it is desirable to generate a scanner profile based on the actual scanner characteristics before performing plate inspection.

[0025] The generated master image is sent to the image data registration unit 102, which links the generated master image with the layout sample data, making it possible to carry out plate inspection using the master image once generated. A master image to be used for plate inspection is selected from the master images registered in the image data registration unit 102 (step S107).

[0026] Next, after setting printing conditions such as paper type and screen (step S108), actual printing is performed by the image forming apparatus 1 based on the submitted document image data (step S109). The output by the actual printing by the image forming apparatus 1 is read by the scanner B, and an RGB read image is generated by the read image generating unit 103.

[0027] The master image is generated by color conversion based on the layout sample, so the content, layout, and color are as intended, and it is an RGB image that does not contain RIP defects or printing defects. The master image registered in the image data registration unit 102 and the read image generated by the read image generation unit 103 are sent to the RIP process defect inspection unit 201, the print defect inspection unit 202, and the color inspection unit 203, respectively.

[0028] Then, the RIP process defect inspection unit 201, the print defect inspection unit 202, and the color inspection unit 203 perform plate inspection including three inspections: inspection for RIP process defects such as garbled characters (step S110), inspection for print defects such as dents and streaks (step S111), and inspection for color differences from the presentation sample (step S112). Next, the display unit 300 displays the inspection results in steps S110, S111, and S112 to notify the user, and the plate inspection process ends (step S113).

[0029] Fig. 5 is a flow chart showing an example of the flow of the calculation process of the CMYK correction amount in the plate inspection system according to the present embodiment. Fig. 6 is a diagram for explaining an example of the calculation process of the CMYK correction amount in the plate inspection system according to the present embodiment. Fig. 5 is a flow chart in which a flow for calculating the color correction amount is added to the flow chart of the plate inspection flow shown in Fig. 4. In the following explanation, explanations of the same processes as those shown in Fig. 5 will be omitted.

[0030] If the color is found to be NG as a result of the plate inspection in steps S110 to S112, the correction amount calculation unit 104 calculates the CMYK correction amount to match the color of the master image by comparing the master image with the read image, as shown in FIG. 6, and reflects the CMYK correction amount in the image forming device 1.

[0031] First, the correction amount calculation unit 104 performs plate inspection in steps S110 to S112 to check whether the color result is OK (step S201), and if the color result is NG (step S201: No), selects whether to perform color correction (step S202).

[0032] When CMYK original image data is output by image forming apparatus 1 and then read by scanner B to obtain an RGB read image (RGB image), this RGB image contains the machine characteristics of image forming apparatus 1 and the scanner characteristics of scanner B. From the original image data and the read image, in a configuration for performing plate inspection and actual printing, it is possible to calculate the correspondence between CMYK and RGB, indicating what kind of RGB image can be obtained for the input CMYK original image data.

[0033] If color correction is to be performed (step S202: Yes), the correction amount calculation unit 104 generates a CMYK and RGB correspondence table based on the CMYK document image data and the RGB image (step S203). The correction amount calculation unit 104 also calculates the correction amount of RGB values ​​(RGB correction amount) for matching the RGB values ​​of the read image to those of the master image based on the difference obtained by comparing the RGB values ​​of the master image and the read image (step S204). The correction amount calculation unit 104 converts the RGB correction amount into a CMYK correction amount (CMYK correction amount) using the CMYK and RGB correspondence table (step S205), and transmits the CMYK correction amount to the image forming device 1 (step S206). After that, the image forming device 1 performs printing and plate inspection again based on the CMYK correction amount.

[0034] In this way, the plate inspection system according to the present embodiment does not require an original presentation sample, and plate inspection can be performed based on the scan data obtained by reading the presentation sample with a scanner and the scanner profile.

[0035] The program executed by the image forming apparatus 1 of this embodiment is provided in a state where it is pre-installed in a ROM (Read Only Memory) or the like. The program executed by the image forming apparatus 1 of this embodiment may be provided by being recorded in a computer-readable recording medium such as a CD-ROM, a flexible disk (FD), a CD-R, or a digital versatile disk (DVD) in the form of a file in an installable or executable format.

[0036] Furthermore, the program executed by the image forming apparatus 1 of the present embodiment may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. Also, the program executed by the image forming apparatus 1 of the present embodiment may be provided or distributed via a network such as the Internet.

[0037] The program executed by the image forming apparatus 1 of this embodiment has a modular structure including the above-mentioned units (data processing unit 100, inspection unit 200), and in terms of actual hardware, an example of a processor such as a CPU (Central Processing Unit) reads out the program from the ROM and executes it, thereby loading the above-mentioned units onto a main memory device, and the data processing unit 100 and inspection unit 200 are generated on the main memory device.

[0038] In the above embodiment, the image forming apparatus of the present invention is described as being applied to a multifunction peripheral having at least two of the functions of a copy function, a printer function, a scanner function, and a facsimile function. However, the image forming apparatus can be applied to any image forming apparatus such as a copier, a printer, a scanner device, or a facsimile device.

[0039] For example, aspects of the present invention are as follows. <1> a generating means for converting the scanned data of a sample of RGB color into L*a*b* values ​​and generating a master image for carrying out a plate inspection of an image printed by an image forming device based on the scanned data of the sample; an information storage means capable of storing the scan data of the appearance sample and the master image in association with each other; a notification means for notifying a result of a plate inspection of an image to be printed by the image forming apparatus based on the scan data of the appearance sample stored in the information storage means and the master image; A plate inspection system equipped with <2> A calculation means for calculating a color conversion amount of an RGB output for a CMYK input for each printing condition; a reflecting unit that calculates a CMYK correction amount for adjusting the color tone of the read image to that of the master image based on the color conversion amount corresponding to the printing conditions of the image forming device and a color tone difference between the RGB master image and the RGB read image of the printed image, and reflects the calculated correction amount in the image forming device; Equipped with <1> The plate inspection system described in <3> The generating means converts the scanned data of the sample into L*a*b* values ​​of Japanese JIS (JIS Z 8781-4); <1> or <2> The plate inspection system described in <4> The image forming apparatus further includes an inspection unit for performing a plate inspection by comparing the master image with an image printed by the image forming apparatus. <1> from <3> 13. The plate inspection system according to claim 12, <5> A plate inspection method executed in a plate inspection system, comprising: A step of converting the scanned data of the RGB sample into L*a*b* values, and then generating a master image for inspecting an image printed by an image forming device based on the scanned data of the sample; a step of notifying a result of inspection of an image to be printed by the image forming device based on the scan data of the appearance sample and the master image stored in an information storage means; Inspection method including. <6> Computer, a generating means for converting the scanned data of a sample of RGB color into L*a*b* values ​​and generating a master image for carrying out a plate inspection of an image printed by an image forming device based on the scanned data of the sample; a notification means for notifying a result of the plate inspection of an image to be printed by the image forming apparatus based on the scan data of the appearance sample stored in an information storage means and the master image; A program to make it function as such. [Explanation of symbols]

[0040] 1. Image forming device 2 PC 100 Data processing unit 101 Master image generation unit 102 Image data registration section 103 Read image generating unit 104 Correction amount calculation unit 200 Inspection Department 201 RIP Process Defect Inspection Department 202 Printing Defect Inspection Department 203 Color Inspection Department 300 Display [Prior art documents] [Patent documents]

[0041] [Patent Document 1] JP 2015-187810 A

Claims

1. a generating means for converting the scanned data of a sample of RGB color into L*a*b* values ​​and generating a master image for carrying out a plate inspection of an image printed by an image forming device based on the scanned data of the sample; an information storage means capable of storing the scan data of the appearance sample and the master image in association with each other; a notification means for notifying a result of a plate inspection of an image to be printed by the image forming apparatus based on the scan data of the appearance sample stored in the information storage means and the master image; A plate inspection system equipped with

2. A calculation means for calculating a color conversion amount of an RGB output for a CMYK input for each printing condition; a reflecting unit that calculates a CMYK correction amount for adjusting the color tone of the read image to that of the master image based on the color conversion amount corresponding to the printing conditions of the image forming device and a color difference between the RGB master image and the RGB read image of the printed image, and reflects the calculated correction amount in the image forming device; The plate inspection system according to claim 1 , comprising:

3. 3. The plate inspection system according to claim 1, wherein the generating means converts the scanned data of the appearance sample into color values ​​of L*a*b* values ​​of Japanese JIS (JIS Z 8781-4).

4. 2. The plate inspection system according to claim 1, further comprising an inspection means for carrying out plate inspection by comparing the master image with the image printed by the image forming device.

5. A plate inspection method executed in a plate inspection system, comprising: A step of converting the RGB scan data of the appearance sample into L*a*b* values, and then generating a master image for carrying out a plate inspection of an image printed by an image forming device based on the scan data of the appearance sample; a step of notifying a result of inspection of an image to be printed by the image forming device based on the scan data of the appearance sample and the master image stored in an information storage means; Inspection method including.

6. Computer, a generating means for converting the scanned data of a sample of RGB color into L*a*b* values ​​and generating a master image for carrying out a plate inspection of an image printed by an image forming device based on the scanned data of the sample; a notification means for notifying a result of the plate inspection of an image to be printed by the image forming apparatus based on the scan data of the appearance sample stored in an information storage means and the master image; A program to make it function as such.

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