Image processing apparatus, image processing method, and program

Abstract

To provide processing for performing inspection of a printed material with high accuracy.SOLUTION: An image processing apparatus has: first inspection means that, with a document image as a reference image, performs inspection of a target image obtained by reading a printed material printed based on the document image; second inspection means that performs inspection of the target image, with a read image obtained by reading the printed material as the reference image; and output means that outputs a result of the inspection of the target image based on a result of the inspection performed by the first inspection means and a result of the inspection performed by the second inspection means.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an image processing technique for inspecting printed matter. [Background technology]

[0002] Printed matter output by a printing device may have stains caused by color materials such as ink or toner adhering to unintended locations, or color loss caused by insufficient color materials adhering to locations where an image is to be formed. As a system for inspecting the presence or absence of such print defects, there is a print inspection system that reads the printed matter output by the printing device with a camera or a line sensor of a scanner, and automatically inspects whether printing is performed normally based on the read image. Such a print inspection system can determine the presence or absence of defects in the printed matter to be inspected based on the difference between a reference image, which is an image of a printed matter without defects, and the read image of the printed matter to be inspected.

[0003] Known methods of inspecting printed matter include an inspection using an original image as a reference image (hereinafter referred to as RIP inspection) and an inspection using a scanned image as a reference image (hereinafter referred to as Scan inspection). RIP is an abbreviation for Raster Image Processor. Patent Document 1 discloses a technique for performing an inspection using a scanned image as a reference image when the inspection level is high, and an inspection using an original image as a reference image when the inspection level is low. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2021-41628 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, since there are factors that reduce the inspection accuracy in both RIP inspection and Scan inspection, there are cases where the method described in Patent Document 1 is unable to perform inspection with high accuracy.

[0006] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a process for inspecting printed matter with high accuracy. [Means for solving the problem]

[0007] In order to solve the above problems, the image processing device of the present invention is characterized in having a first inspection means for inspecting a target image obtained by reading a printed matter printed based on an original image, using an original image as a reference image, a second inspection means for inspecting the target image, using a read image obtained by reading the printed matter as a reference image, and an output means for outputting an inspection result for the target image based on the inspection result by the first inspection means and the inspection result by the second inspection means. Effect of the Invention

[0008] Printed materials can be inspected with high precision. [Brief description of the drawings]

[0009] [Figure 1] Diagram showing the configuration of a print inspection system [Diagram 2] Block diagram showing the functional configuration of an image processing device [Diagram 3] 1 is a flowchart showing a process executed by an image processing device; [Figure 4] A diagram showing an example of a user interface. [Diagram 5] Flowchart showing defect determination processing [Figure 6] Flowchart showing defect determination processing [Figure 7] Flowchart showing defect determination processing DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Each embodiment will be described below with reference to the drawings. Note that the following embodiments do not necessarily limit the present invention. Furthermore, not all of the combinations of features described in each embodiment are necessarily essential to the solution of the present invention.

[0011] [First embodiment] RIP inspection and Scan inspection each have good and bad points in terms of accuracy. In RIP inspection, since the unprinted original image does not contain defects, overdetection due to defects in the reference image does not occur. However, since the original image and the scanned image differ in color characteristics, thin line reproduction characteristics, geometric distortion, etc., overdetection due to the difference in these image characteristics is likely to occur. On the other hand, in Scan inspection, since the reference image and the image to be inspected are both scanned images, overdetection due to the difference in image characteristics is unlikely to occur. However, if the scanned image used as the reference image contains micro defects, it may be determined that there are defects even in areas of the image to be inspected that are free of defects. In addition, if the scanned image contains macro defects such as uneven density and the image to be inspected also contains similar macro defects, defects that should be detected may be overlooked.

[0012] Therefore, the image processing device in this embodiment performs both RIP inspection and Scan inspection, and judges the presence or absence of defects based on the results of the two inspections. This reduces overdetection compared to conventional methods, and enables inspection of printed matter with high accuracy.

[0013] <Print inspection system configuration> 1 is a diagram showing the configuration of a print inspection system that outputs and inspects printed matter in embodiment 1. The print inspection system in the first embodiment has an image processing device 100, a printing server 180, and a printing device 190.

[0014] The printing server 180 generates a print job including an original to be printed, and submits the print job to the printing device 190. The printing device 190 forms an image on a print medium based on the print job submitted from the printing server 180. The printing device 190 has a paper feed unit 191, and a user can supply the print medium to the paper feed unit 191 in advance. When a print job is submitted, the printing device 190 forms an image on one or both sides of the print medium while transporting the print medium supplied to the paper feed unit 191 along a transport path 192, and sends it to the image processing device 100.

[0015] The image processing device 100 inspects a print medium (medium to be inspected) on which printing has been performed for defects. The medium to be inspected is obtained by forming an image on the print medium by the printing device 190, and is transported through a transport path 192 inside the printing device 190. The image processing device 100 has a CPU 101, a RAM 102, and a ROM 103. The image processing device 100 also has an image reading device 105, a printing device interface (I / F) 106, a general-purpose interface (I / F) 107, a user interface (UI) panel 108, and a main bus 109. The image processing device 100 also has a transport path 110 for the print medium connected to the transport path 192 of the printing device 190. The image processing device 100 also has an output tray 111 to which the medium to be inspected that has been determined to pass the inspection is output, and an output tray 112 to which the medium to be inspected that has been determined to fail the inspection is output. 1, the output tray 111 and the output tray 112 are connected to the CPU 101 via the main bus 109. The destination of the medium to be inspected is set to either the output tray 111 or the output tray 112 depending on the inspection result of the medium to be inspected.

[0016] The image processing device 100 can be realized by a computer including a processor and a memory. For example, a processor such as a CPU 101 executes a program stored in a memory such as a RAM 102 or a ROM 103 to realize the functions of each unit. The processor such as the CPU 101 can also control each module in the image processing device 100 as necessary. The image processing device 100 may be composed of a plurality of processing devices connected via a network, for example. The CPU 101 is a processor that controls each unit in the image processing device 100. The RAM 102 temporarily holds applications executed by the CPU 101, data used in image processing, etc. The ROM 103 stores a group of programs executed by the CPU 101.

[0017] The image reading device 105 reads one or both sides of the print medium sent from the printing device 190 on the conveying path 110, and obtains the read result as image data. Since the conveying path 110 becomes the background when the image reading device 105 reads the image of the print medium, the conveying path 110 can be configured to have a color (e.g., black) that is easily distinguishable from the print medium on the image. The printing device I / F 106 is connected to the printing device 190, and the image processing device 100 can communicate with the printing device 190 through the printing device I / F 106. For example, the printing device 190 and the image processing device 100 can be synchronized via the printing device I / F 106 to notify each other of their operating status. The UI panel 108 can notify the user of information. The UI panel 108 may be a display device such as a liquid crystal display, and can function as a user interface for the image processing device 100. The UI panel 108 can notify the user of, for example, the current status or settings of the image processing device 100. The UI panel 108 may also include an input device such as a touch panel or buttons, and the image processing device 100 can receive instructions from a user via the input device. The main bus 109 is a transmission path that connects the modules of the image processing device 100.

[0018] While the print medium output from the printer 190 is being transported along the transport path 110, the image processing device 100 performs an inspection process to check for defects in the print medium based on image data of the print medium acquired by the image reading device 105. If the print medium is determined to pass the inspection process, it is transported to an output tray 111. If the print medium is determined to fail the inspection process, it is transported to an output tray 112. With this operation, only print media determined to have no defects is output onto the output tray 111.

[0019] Although the print inspection system in this embodiment includes the printing server 180, it may be configured not to include the printing server 180. For example, the printing device 190 may generate a print job by itself, or may receive a print job from another device connected to the printing device 190. Also, in this embodiment, the image processing device 100 includes the image reading device 105, the conveying path 110, the output tray 111, etc., but the image processing device 100 does not need to include all of the components. For example, the image processing device 100 may have only the CPU 101, the RAM 102, and the ROM 103, and the image reading device 105, the user interface (UI) panel 108, etc. may be separate devices.

[0020] <Functional configuration of image processing device 100> Fig. 2 is a block diagram showing the functional configuration of the image processing device 100 in this embodiment. The CPU 101 functions as the functional configuration shown in Fig. 2 by reading and executing a program stored in the ROM 103 or the like using the RAM 102 as a work memory. Note that it is not necessary for all of the processes shown below to be executed by the CPU 101, and the image processing device 100 may be configured so that a part or all of the processes are executed by one or more processing circuits other than the CPU 101. The image processing device 100 has a reference image acquisition unit 201, a target image acquisition unit 202, an inspection information acquisition unit 203, a RIP inspection processing unit 204, a Scan inspection processing unit 205, a defect determination unit 206, and a display control unit 207.

[0021] The reference image acquisition unit 201 acquires document image data representing a document image to be printed as reference image data for RIP inspection, and acquires read image data obtained by reading a reference printed matter as reference image data for Scan inspection. The reference image acquisition unit 201 stores the acquired reference image data in the RAM 102 or the ROM 103. Note that the reference image acquisition unit 201 acquires read image data generated by the image reading device 105 reading the medium to be inspected on the conveying path 110, but may acquire read image data generated using another device. For example, read image data generated by a device other than the image reading device 105 may be stored in a storage device such as an HDD, and the reference image acquisition unit 201 may acquire the read image data from the storage device.

[0022] When using the scanned image data as the reference image data for the Scan inspection, the S / N ratio may be improved by combining multiple images to make it easier to detect defects in the image to be inspected. For example, the printing device 190 outputs multiple images of the same pattern, and the image reading device 105 generates multiple scanned images by reading the output. The reference image acquisition unit 201 calculates the average of the pixel values ​​of the multiple scanned images using formula (1).

[0023]

number

[0024] Here, (x, y) represents the coordinates of each pixel. i (x, y) represents the pixel values ​​of the multiple scanned images at the position (x, y), and I o (x, y) represents the pixel value of the image after synthesis at the position (x, y), and N represents the number of scanned images to be synthesized.

[0025] The target image acquisition unit 202 acquires inspection target image data representing a read image of an inspection target medium on which printing has been performed by the printing device 190. The target image acquisition unit 202 stores the acquired inspection target image data in the RAM 102 or the ROM 103. In this embodiment, the target image acquisition unit 202 acquires read image data generated by the image reading device 105 reading the inspection target medium on the transport path 110. The inspection information acquisition unit 203 acquires inspection job information related to inspection settings and information related to the inspection level based on a user instruction acquired via the UI panel 108. Note that the inspection information acquisition unit 203 may acquire inspection information representing predetermined inspection settings and inspection levels from a storage device such as an HDD.

[0026] The RIP inspection processing unit 204 judges the presence or absence of defects in the inspection target image by comparing the original image as a reference image with the inspection target image. The Scan inspection processing unit 205 judges the presence or absence of defects in the inspection target image by comparing the scanned image as a reference image with the inspection target image. The defect judgment unit 206 judges the presence or absence of defects in the inspection target image based on the results of the RIP inspection and the Scan inspection. The display control unit 207 displays a UI on the UI panel 108 for notifying the user of information and for allowing the user to input information required for processing.

[0027] <Processing Executed by Image Processing Device 100> The flow of processing executed by the image processing device 100 in this embodiment will be described with reference to the flowchart in Fig. 3. The processing shown in the flowchart in Fig. 3 starts when a user inputs an instruction via the UI panel 108 or the like and the CPU 101 accepts the input instruction. Hereinafter, each step (process) will be represented by adding an S before the reference number.

[0028] In S11, the display control unit 207 displays a UI on the UI panel 108 for the user to input information required for the inspection. FIG. 4 illustrates an example of the UI displayed in this step. In FIG. 4, an inspection mode setting area 1101 is an area for setting the inspection mode, and the user can specify a reference image to be used for the inspection by pressing the inspection mode setting area 1101. "RIP" indicates an inspection mode based on document image data, "Scan" indicates an inspection mode based on scanned image data, and "RIP&Scan" indicates an inspection mode based on both document image data and scanned image data. When an inspection mode is selected, the screen transitions to an image specification screen, and an image specified by the user is stored in the RAM 102 or ROM 103 as a reference image. The inspection job setting area 1102 is an area for setting information on an inspection job in which a print job is associated with information on the image data to be inspected and information on the inspection settings. The user can specify a previously registered inspection job by pressing the inspection job setting area 1102. The inspection job specified by the user is stored in the RAM 102 or ROM 103.

[0029] The inspection level setting area 1103 is an area for setting the inspection level to be used for the inspection, and the user can select the inspection level from a pull-down menu. A value representing the selected inspection level is stored in the RAM 102 or the ROM 103. The inspection level is associated with a processing parameter required to detect the corresponding defect for each inspection level according to the size and contrast of the defect to be detected. In the inspection process, the defect is detected according to the inspection level selected by the user. In this embodiment, there are five inspection levels, and the higher the inspection level, the lower the defect is detected, and the higher the contrast and the larger the defect is detected. Note that the number of inspection levels may be any number, and the correspondence between the inspection levels and the features of the defect to be detected is not limited to the above example.

[0030] The inspection NG operation setting area 1104 is an area for setting the operation when the print is judged to have a defect in the inspection. "Stop on continuous NG" is a setting for stopping printing when the print is defective and a predetermined number of consecutive NG judgments are made. "Recovery" is a setting for stopping the print job when the print is defective and judged to have a NG judgment, and reprinting from the page judged to be defective. The inspection execution area 1105 is an area for executing the inspection process, and when the inspection execution area 1105 is pressed, the inspection process is executed based on the information set in 1101 to 1104. The display window 1106 is an area for displaying the inspection target image, defect map, and judgment result. The inspection image display window 1107 is an area for displaying the inspection target image. The RIP judgment result display window 1108 is an area for displaying the judgment result by the RIP inspection. The Scan judgment result display window 1109 is an area for displaying the judgment result by the Scan inspection. The overall result display window 1110 is an area for displaying an overall judgment result that combines the judgment results of both the RIP inspection process and the Scan inspection process. The list display area 1111 is an area for displaying a list of defects detected in the RIP inspection judgment result, the Scan inspection judgment result, and the overall judgment result.

[0031] In S12, the reference image acquisition unit 201 acquires document image data representing a document image to be printed as reference image data for RIP inspection, and acquires read image data obtained by reading a reference printed matter as reference image data for Scan inspection. In S13, the inspection information acquisition unit 203 acquires an inspection job. Specifically, the inspection information acquisition unit 203 acquires information on an inspection job set in the inspection job setting area 1102. In addition, the target image acquisition unit 202 acquires image data to be inspected. In S14, the inspection information acquisition unit 203 acquires an inspection level. Specifically, the inspection information acquisition unit 203 refers to information set in the inspection level setting area 1103, and acquires processing parameters related to the contrast and size of a defect associated with the inspection level. The order of the processes from S12 to S14 is not limited to the above example, and may be, for example, S14, S13, and S12, or a plurality of processes may be performed in parallel.

[0032] In S15, the inspection information acquisition unit 203 refers to the inspection mode set in the inspection mode setting area 1101 and proceeds with the process. Specifically, if the inspection mode is "RIP", the process proceeds to S16, if it is "Scan", the process proceeds to S18, and if it is "RIP&Scan", the process proceeds to S20. In S16, the RIP inspection processing unit 204 executes a RIP inspection using the original image data as the reference image data for the inspection target image represented by the inspection target image data. In this embodiment, the RIP inspection processing unit 204 performs a correction process for the color reproduction characteristics and the thin line reproduction characteristics of the original image in order to suppress overdetection of defects. In the correction process of the color reproduction characteristics, the correction is performed by referring to a LUT (lookup table) in which the correspondence between CMYK values ​​and RGB values ​​is described for each characteristic of the printing device 190, printing medium, and output condition. The LUT is created in advance and stored in a storage device such as a HDD. In addition, in the correction process of the thin line reproduction characteristics, the correction is performed using a filter with a predetermined filter coefficient. A thin line chart is output and read, and based on the line profile of the thin line, a filter coefficient for matching the line width with the read image and a filter coefficient for correcting blurring of edges during reading are calculated in advance.

[0033] The RIP inspection processor 204 applies the above two types of correction processing to the original image to generate a reference image for RIP inspection. The RIP inspection processor 204 also performs processing to convert the resolution of the original image to match the image size and resolution of the inspection target image used during inspection. The RIP inspection processor 204 aligns the reference image with the inspection target image, calculates the difference in pixel values ​​between the two images, and determines pixels for which the calculated difference is greater than a predetermined threshold as defective pixels. In this embodiment, the RIP inspection processor 204 determines the presence or absence of point defects and linear defects by referring to the contrast threshold for the difference and the sizes of point defects and linear defects stored for each inspection level.

[0034] In S17, the display control unit 207 displays the defect map in the display window 1106 as a result of the inspection process in S16. The defect map is a map showing the coordinate positions of defects detected by the inspection. The defect map is an image file having the same vertical and horizontal sizes as the reference image and the image to be inspected. In the defect map, for example, a pixel value of (R,G,B)=(255,255,255) is stored at a coordinate position where a defect exists, and a pixel value of (R,G,B)=(0,0,0) is stored at a coordinate position where no defect exists. In this embodiment, if there is a point-like defect, a pixel value of (R,G,B)=(255,0,0) is stored at the corresponding coordinate position, and if there is a line-like defect, a pixel value of (R,G,B)=(0,255,0) is stored at the corresponding coordinate position. Note that the pixel values ​​in the defect map are not limited to the above example as long as the presence or absence of a defect and the type of defect can be identified.

[0035] In S18, the Scan inspection processing unit 205 executes a Scan inspection using the read image data as reference image data for the inspection target image represented by the inspection target image data. The Scan inspection processing unit 205 aligns the reference image with the inspection target image, calculates the difference in pixel values ​​between the two images, and determines pixels for which the calculated difference is greater than a predetermined threshold value as defective pixels. In S19, the display control unit 207 displays a defect map in the display window 1106 as a result of the inspection processing in S18.

[0036] In S20, the RIP inspection processing unit 204 executes a RIP inspection similar to the process of S16. In S21, the Scan inspection processing unit 205 executes a Scan inspection similar to the process of S18. In S22, the defect determination unit 206 determines whether or not there is a defect in the inspection target image based on both the determination result of S20 and the determination result of S21. Details of the process of the defect determination unit 206 will be described later.

[0037] In S23, the display control unit 207 displays a defect map and an inspection report as the overall judgment result in S22 in a display window 1106. The display control unit 207 displays the defect map that is the judgment result in S20 in a RIP judgment result display window 1108, and displays the defect map that is the judgment result in S21 in a Scan judgment result display window 1109. The display control unit 207 displays the defect map that is the overall judgment result in S22 in an overall result display window 1110. The defects displayed in the overall result display window 1110 are defects that combine the locations judged to be defective by the defect judgment unit 206, the locations judged to be defective in the RIP inspection, and the locations judged to be defective in the Scan inspection, and are shown in different colors.

[0038] For example, if four defects (No1, No3, No4, No5) are detected in the RIP inspection, three defects (No1, No2, No3) are detected in the Scan inspection, and two defects (No1, No3) are detected in the overall judgment, each defect is color-coded based on the inspection result. In this embodiment, the display control unit 207 displays the defects (No1, No3) detected in the overall judgment with pixel values ​​of (R,G,B)=(255,255,0). In addition, the display control unit 207 displays the defects (No4, No5) detected only in the RIP inspection with pixel values ​​of (R,G,B)=(255,0,0), and displays the defect (No2) detected only in the Scan inspection with pixel values ​​of (R,G,B)=(0,0,255). The display control unit 207 displays the coordinates where no defect is detected with pixel values ​​of (R,G,B)=(0,0,0). The display control unit 207 displays the results of each determination in a list in a list display area 1111 as an examination report.

[0039] In this embodiment, the RIP inspection result, the Scan inspection result, and the overall judgment result are all displayed, but it is also possible to display only the overall judgment result. Also, it is also possible to allow the user to select the inspection results to be displayed.

[0040] <Processing Executed by Defect Determination Unit 206> FIG. 5 is a flowchart showing the flow of the process executed by the defect determination unit 206 in S22. In S2201, the defect determination unit 206 acquires a defect map which is a result of the RIP inspection executed in S20. The defect map is generated by the RIP inspection processing unit 204. In S2202, the defect determination unit 206 acquires a defect map which is a result of the Scan inspection executed in S21. The defect map is generated by the Scan inspection processing unit 205. In S2203, the defect determination unit 206 compares each pixel of the defect maps acquired in S2201 and S2202, and determines whether or not there is a defect at the same coordinate position. If there is a defect at the same coordinate position, the process proceeds to S2204, and if there is no defect at the same coordinate position, the process proceeds to S2205. Note that the defect determination unit 206 in this embodiment determines whether the positions of the defects are at the same coordinates, but in order to increase the accuracy of the overall determination, it may also determine whether or not the types of the defects match in addition to the positions of the defects.

[0041] In S2204, the defect determination unit 206 determines that there is a defect if there is a defect at the same coordinate position, and stores a pixel value of (R,G,B)=(255,255,0) at the corresponding coordinates in the defect map. In S2205, the defect determination unit 206 determines that there is no defect if there is no defect at the same coordinate position, and stores a pixel value of (R,G,B)=(0,0,0) at the corresponding coordinates in the defect map. In S2206, the defect determination unit 206 determines whether or not the presence or absence of a defect has been determined for all pixel positions, and if the determination has been completed, the process proceeds to S2207, and if the determination has not been completed, the process returns to S2203. In S2207, the defect determination unit 206 outputs the defect map to the storage device, and the process of S22 ends. Note that the final output destination of the defect map is not limited to the storage device, and may be directly output to the display control unit 207 or may be output to another device.

[0042] As described above, the image processing device 100 in this embodiment performs both RIP inspection and Scan inspection, and by combining the results of both inspections, it is possible to improve the inspection accuracy and perform defect judgment with less overdetection of defects.

[0043] [Second embodiment] In the first embodiment, both the RIP inspection and the Scan inspection are performed, and when a defect is present at the same coordinate position in the defect map, it is determined that a defect is present at the corresponding coordinate position. In this embodiment, an edge area is extracted from the image to be inspected, and an inspection process is performed for the edge area using the scanned image as a reference image, and an inspection process is performed for the non-edge area using the original image and the scanned image as reference images. In the RIP inspection using the original image as the reference image, overdetection is likely to occur in the edge area due to differences in thin line reproduction characteristics, so the area is divided into edge areas and non-edge areas and the area for performing the overall judgment performed in the first embodiment is determined. This makes it possible to suppress overdetection of defects. Note that the hardware configuration and functional configuration of the image processing device in this embodiment are the same as those in the first embodiment, so the description will be omitted. In the following, the parts that are different between this embodiment and the first embodiment will be mainly described. Note that the same components as those in the first embodiment will be described with the same reference symbols.

[0044] <Processing Executed by Defect Determination Unit 206> FIG. 6 is a flowchart showing the flow of the process executed by the defect determination unit 206 in S22. In S3201, the defect determination unit 206 acquires a defect map which is a result of the RIP inspection executed in S20. In S3202, the defect determination unit 206 acquires a defect map which is a result of the Scan inspection executed in S21. In S3203, the defect determination unit 206 acquires edge information of the inspection target image. Specifically, the defect determination unit 206 detects edges by applying a known edge detection filter such as a Sobel filter or a Laplacian filter to the inspection target image, and generates edge information by binarizing pixel values ​​after the filter application. The defect determination unit 206 may further apply an expansion filter or a contraction filter to the edge region. In S3204, the defect determination unit 206 judges whether the coordinates of the defect map acquired in S3201 and S3202 are edge regions based on the pixel values ​​of the edge region acquired in S3203. If the defect map coordinates are in an edge region, the process proceeds to S3205; if not, the process proceeds to S3206.

[0045] In S3205, the defect determination unit 206 adopts the determination result of the defect map acquired in S3202 for the coordinates determined to be an edge area. In S3206, the defect determination unit 206 compares each pixel of the defect maps acquired in S3201 and S3202, and determines whether or not there is a defect at the same coordinate position. If there is a defect at the same coordinate position, the process proceeds to S3207, and if there is no defect at the same coordinate position, the process proceeds to S3208. In S3207, the defect determination unit 206 determines that there is a defect if there is a defect at the same coordinate position, and stores a pixel value of (R,G,B)=(255,255,0) at the corresponding coordinates in the defect map.

[0046] In S3208, if there is no defect at the same coordinate position, the defect determination unit 206 determines that there is no defect, and stores pixel values ​​of (R,G,B)=(0,0,0) at the corresponding coordinates in the defect map. In S3209, the defect determination unit 206 determines whether or not the presence or absence of a defect has been determined for all pixel positions, and if so, proceeds to S3210, and if not, returns to S3204. In S3210, the defect determination unit 206 outputs the defect map to the storage device, and ends the processing of S22.

[0047] As described above, the image processing device 100 in this embodiment uses the inspection results of the Scan inspection for edge areas where the RIP inspection is difficult, and uses the inspection results of both the RIP inspection and the Scan inspection for non-edge areas. This makes it possible to obtain good inspection results even for inspection target images with many edges.

[0048] [Third embodiment] In this embodiment, whether or not to use both the RIP inspection and the Scan inspection results is determined depending on the inspection level. When the inspection level is high, the RIP inspection may overdetect due to minute differences in image characteristics, so the Scan inspection is performed. When the inspection level is medium or lower, both the RIP inspection and the Scan inspection are performed. Note that the hardware configuration and functional configuration of the image processing device in this embodiment are the same as those in the first embodiment, so a description thereof will be omitted. The following mainly describes the parts that differ between this embodiment and the first embodiment. Note that the same configurations as those in the above-mentioned embodiment are described with the same reference numerals.

[0049] <Processing Executed by Defect Determination Unit 206> FIG. 7 is a flowchart showing the flow of the process executed by the defect determination unit 206 in S22. In S4201, the defect determination unit 206 acquires a defect map which is a result of the RIP inspection executed in S20. In S4202, the defect determination unit 206 acquires a defect map which is a result of the Scan inspection executed in S21. In S4203, the defect determination unit 206 acquires the inspection level set in the inspection level setting area 1103. In S4204, the defect determination unit 206 compares the inspection level acquired in S4203 with a predetermined threshold, and if it is greater than the threshold, the process proceeds to S4205, and if it is equal to or less than the threshold, the process proceeds to S4206. In this embodiment, the threshold is set to 4 for the five inspection levels, and the process proceeds to S4205 only when the highest inspection level, 5, is set, but the threshold is not limited to the above example.

[0050] In S4205, when the inspection level is set higher than the threshold, the defect determination unit 206 adopts the determination result of the defect map acquired in S4202. When the inspection level is high, the sensitivity to the contrast and size of the defect to be detected increases, and adopting the result of the RIP inspection increases the frequency of overdetection, so the defect map of only the Scan inspection is adopted as the final determination result.

[0051] In S4206, the defect determination unit 206 compares each pixel of the defect maps acquired in S4201 and S4202, and determines whether or not there is a defect at the same coordinate position. If there is a defect at the same coordinate position, the process proceeds to S4207, and if there is no defect at the same coordinate position, the process proceeds to S4208. In S4207, the defect determination unit 206 determines that there is a defect if there is a defect at the same coordinate position, and stores a pixel value of (R,G,B)=(255,255,0) at the corresponding coordinates in the defect map. In S4208, the defect determination unit 206 determines that there is no defect if there is no defect at the same coordinate position, and stores a pixel value of (R,G,B)=(0,0,0) at the corresponding coordinates in the defect map.

[0052] In S4209, the defect determination unit 206 determines whether or not the presence or absence of a defect has been determined for all pixel positions, and if so, proceeds to S4210, otherwise returns to S4206. In S4210, the defect determination unit 206 outputs the defect map to the storage device, and ends the processing of S22.

[0053] As described above, the image processing device 100 in this embodiment adopts only the results of the Scan inspection when the inspection level is set to high, and uses the results of both the RIP inspection and the Scan inspection at other inspection levels. This makes it possible to perform highly accurate inspection regardless of the inspection level.

[0054] [Other embodiments] In the above-described embodiment, a form in which defects are detected by inspecting a printed matter has been described, but the present invention can also be applied to a form in which a pattern, texture, or the like having a predetermined characteristic is detected in a printed matter.

[0055] The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions. [Explanation of symbols]

[0056] 100 Image processing device 204 RIP inspection processing unit 205 Scan inspection processing unit 206 Defect Judgment Section

Claims

1. a first inspection means for inspecting a target image obtained by reading a printed matter printed based on an original image using the original image as a reference image; a second inspection means for inspecting the target image by using a read image obtained by reading a printed matter based on the original image as a reference image; an output means for outputting both the inspection result by the first inspection means and the inspection result by the second inspection means; 1. An image processing device comprising:

2. 2. The image processing device according to claim 1, wherein the output means determines whether or not there is a defect in the target image based on the inspection results from the first inspection means and the inspection results from the second inspection means, and outputs the determination result as the inspection result for the target image.

3. 3. The image processing apparatus according to claim 2, wherein the output means determines whether or not there is a defect in the target image based on the position of the defect detected by the first inspection means and the position of the defect detected by the second inspection means.

4. 4. The image processing apparatus according to claim 3, wherein when the position of the defect detected by the first inspection means and the position of the defect detected by the second inspection means match, it is determined that the target image has a defect.

5. 5. The image processing device according to claim 4, wherein the output means determines that the target image contains a defect when the position and type of the defect detected by the first inspection means match the position and type of the defect detected by the second inspection means.

6. 3. The image processing apparatus according to claim 2, wherein the output means acquires edge information of the target image, and determines whether or not there is a defect in the target image based on the edge information.

7. 7. The image processing device according to claim 6, wherein the output means determines the presence or absence of defects for edge areas in the target image using only the inspection results of the second inspection means, and determines the presence or absence of defects for non-edge areas in the target image using both the inspection results of the first inspection means and the inspection results of the second inspection means.

8. 3. The image processing apparatus according to claim 2, wherein the output means determines whether or not there is a defect in the target image based on an inspection level for the target image.

9. 9. The image processing device according to claim 8, wherein the output means determines the presence or absence of a defect using only the inspection result of the second inspection means when the inspection level is high, and determines the presence or absence of a defect using both the inspection result of the first inspection means and the inspection result of the second inspection means when the inspection level is low.

10. 2. The image processing apparatus according to claim 1, wherein the output means displays the inspection result by the first inspection means and the inspection result by the second inspection means in different colors.

11. A program for causing a computer to function as the image processing device according to any one of claims 1 to 10.

12. a first inspection step of inspecting a target image obtained by reading a printed matter printed based on an original image using the original image as a reference image; a second inspection step of inspecting the target image using a read image obtained by reading a printed matter based on the original image as a reference image; an output step of outputting both the inspection result in the first inspection step and the inspection result in the second inspection step; An image processing method comprising:

Images