JP2021190928A - Image inspection device, image forming apparatus, image inspection method, and program - Google Patents

Abstract

To automatically detect the positional deviation between individual images based on a plurality of pieces of image data on a recording medium in an inspection image obtained by combining the individual images formed at different timings.SOLUTION: An image inspection device comprises: correct answer information acquisition means (correct answer information acquisition unit 51) that acquires correct answer information including composite image data of a plurality of pieces of image data and position information on the boundary part between adjacent individual images; positioning means (positioning unit 52) that performs positioning between the composite image data and read image data obtained by reading an inspection image formed on a recording medium; boundary part detection means (positional deviation determination unit 53) that detects, from the read image data, an inspection boundary part based on the position information on the boundary part; and positional deviation detection means (positional deviation detection unit 53) that compares a pixel value between the boundary part of the composite image data and the inspection boundary part of the read data in a state in which the positioning is performed, and thereby detects the positional deviation between the individual images in the inspection image.SELECTED DRAWING: Figure 2

Description

The present invention relates to an image inspection device, an image forming device, an image inspection method and a program.

Conventionally, in decorative (processing) printing that adds value to printed matter, there is a process of printing the decorated part and the non-decorated part at different timings, and the decorated part and the non-decorated part are combined. In the final printed matter, which is a printed matter, when the decorated portion and the non-decorated portion are printed adjacent to each other, it is desired that there is no positional deviation in terms of quality.

As an image inspection technique for the additional print result in the case of performing additional print to print the decorative portion, for example, in Patent Document 1, the influence of the pre-printed image data on the inspection is reduced and the image to be inspected is generated. , It is described that the quality of the reprint printing result is inspected.

Japanese Unexamined Patent Publication No. 2011-70548

When the reprint image is inspected by the technique described in Patent Document 1, the quality of the reprint print result in which the influence of the preprint image data is reduced is only inspected, and the preprint formed on the recording medium is inspected. Since the purpose is not to detect the misalignment between the image data and the reprinted image data, the user has to visually inspect the misalignment of the final printed matter.

An object of the present invention is to automatically perform positional deviation between individual images in an inspection image obtained by forming and synthesizing individual images based on a plurality of image data on a recording medium at different timings.

In order to solve the above problems, the image inspection apparatus according to claim 1 is the image inspection device.
An image inspection device that detects positional deviations between individual images in an inspection image obtained by forming individual images based on a plurality of image data on the same recording medium at different timings and synthesizing them.
Correct answer information acquisition means for acquiring correct answer information including composite image data of a plurality of image data and position information of a boundary portion of adjacent individual images, and
An alignment means for aligning the composite image data and the read image data obtained by reading the inspection image formed on the recording medium, and
A boundary portion detecting means for detecting an inspection boundary portion based on the position information of the boundary portion from the read image data, and a boundary portion detecting means.
Positional deviation detection that detects the positional deviation between individual images in the inspection image by comparing the pixel values of the boundary portion of the composite image data and the inspection boundary portion of the read image data in the aligned state. Means and
To prepare for.

The invention according to claim 2 is the invention according to claim 1.
The position information of the boundary portion includes edge information of the plurality of image data.

The invention according to claim 3 is the invention according to claim 1 or 2.
The correct answer information includes direction information indicating the directionality of the boundary portion.
The misalignment detecting means detects the misalignment based on the direction information.

The invention according to claim 4 is the invention according to any one of claims 1 to 3.
It is provided with a misalignment width setting means for setting a misalignment width to be detected.

The image forming apparatus of the invention according to claim 5 is
An image forming unit that forms the inspection image on a recording medium,
The image inspection device according to any one of claims 1 to 4, which inspects the inspection image formed by the image forming unit.
To prepare for.

The invention according to claim 6 is the invention according to claim 5.
A reading unit for acquiring read image data obtained by reading an inspection image formed on a recording medium is provided.

The invention according to claim 7 is the invention according to claim 6.
When the misalignment is detected, the recording medium on which the inspection image in which the misalignment has occurred is discharged to a tray different from the recording medium in which the inspection image in which the misalignment has occurred is formed. A paper ejection control means is provided.

The invention according to claim 8 is the invention according to claim 6 or 7.
A stop control means for automatically stopping the image forming operation when the misalignment is detected is provided.

The image inspection method of the invention according to claim 9 is
It is an image inspection method for detecting a positional deviation between individual images in an inspection image obtained by forming individual images based on a plurality of image data on the same recording medium at different timings and synthesizing them.
A correct answer information acquisition step for acquiring correct answer information including composite image data of a plurality of image data and position information of a boundary portion of adjacent individual images, and
An alignment step for aligning the composite image data and the read image data obtained by reading the inspection image formed on the recording medium, and
A boundary portion detection step for detecting an inspection boundary portion based on the position information of the boundary portion from the read image data, and a boundary portion detection step.
Positional deviation detection that detects the positional deviation between individual images in the inspection image by comparing the pixel values of the boundary portion of the composite image data and the inspection boundary portion of the read image data in the aligned state. Steps and
including.

The program of the invention according to claim 10 is
A computer of an image inspection device that detects a positional deviation between individual images in an inspection image obtained by forming individual images based on a plurality of image data on the same recording medium at different timings and synthesizing them.
Correct answer information acquisition means for acquiring correct answer information including composite image data of a plurality of image data and position information of a boundary portion of adjacent individual images.
An alignment means for aligning the composite image data and the scanned image data obtained by reading the inspection image formed on the recording medium.
A boundary portion detecting means for detecting an inspection boundary portion from the read image data based on the position information of the boundary portion.
Positional deviation detection that detects the positional deviation between individual images in the inspection image by comparing the pixel values of the boundary portion of the composite image data and the inspection boundary portion of the read image data in the aligned state. means,
To function as.

According to the present invention, it is possible to automatically detect the positional deviation between individual images in an inspection image obtained by forming and synthesizing individual images based on a plurality of image data on a recording medium at different timings.

It is a schematic sectional drawing which shows the whole structure of the image forming apparatus in embodiment of this invention. It is a block diagram which shows the functional structure of an image forming apparatus. It is a flowchart which shows the image inspection process executed by an image forming apparatus. It is a figure which shows the composite image data and the boundary part position information. It is a figure which shows the direction information in the boundary part position information. It is a figure which shows the case where the feature point used for alignment is an edge. It is a figure which shows the case where the feature point used for alignment is a marker. It is a figure which shows the pixel value comparison in a window. It is a figure which shows the continuity of the misalignment candidate coordinates, and the misalignment width.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the scope of the invention is not limited to the illustrated examples.

[Structure of image forming apparatus]
FIG. 1 is a schematic cross-sectional view showing the overall configuration of the image forming apparatus 100. FIG. 2 is a block diagram showing a functional configuration of the image forming apparatus 100. The image forming apparatus 100 forms an image composed of a plurality of colors on a recording medium.
The recording medium is not particularly limited, and a known recording medium can be used. For example, in addition to paper such as plain paper and coated paper, various media such as sheet-shaped resin capable of fixing a coloring material adhering to the surface can be mentioned.

As shown in FIG. 2, the image forming apparatus 100 includes a control unit 11, a storage unit 12, an operation unit 13, a display unit 14, a communication unit 15, an image generation unit 16, a scanner unit 17, an image memory 18, and an image processing unit 19. , An image forming unit 20, an image reading unit 30, a cutting unit 40, an inspection unit 50, and the like are provided.

The control unit 11 includes a CPU (Central Processing Unit) and a RAM (Random Access Memory).
) And the like, and each unit is controlled by reading and executing various programs from the storage unit 12.
For example, the control unit 11 causes the image processing unit 19 to process the image data generated by the image generation unit 16 or the scanner unit 17 and held in the image memory 18, based on the image data after the image processing. The image forming unit 20 forms an image on the recording medium.

The storage unit 12 stores a program that can be read by the control unit 11, data used when the program is executed, and the like. As the storage unit 12, a large-capacity memory such as a hard disk can be used.

As shown in FIG. 1, the operation unit 13 and the display unit 14 are user interfaces provided on the upper part of the image forming apparatus 100.
The operation unit 13 generates an operation signal according to the user's operation and outputs it to the control unit 11. As the operation unit 13, a keypad, a touch panel integrally configured with the display unit 14, and the like can be used.
When the inspection unit 50 detects the misalignment of the inspection image on the recording medium, the operation unit 13 discharges the printed matter in which the misalignment has occurred to a tray different from the printed matter in which the misalignment has not occurred. It is used when selecting whether or not. When it is selected to eject the paper to another tray, the control unit 11 controls to eject the printed matter in which the misalignment has occurred to a tray different from the printed matter in which the misalignment has not occurred. That is, the control unit 11 functions as a paper ejection control means.
Further, the operation unit 13 is used when the inspection unit 50 selects whether or not to automatically stop the image forming operation when the inspection unit 50 detects the positional deviation of the inspection image on the recording medium. When it is selected to automatically stop, the control unit 11 controls to automatically stop the image forming operation when the positional deviation is detected. That is, the control unit 11 functions as a stop control means.
Further, the operation unit 13 is used when setting a threshold value of the misalignment width used for determining the occurrence of misalignment. That is, the operation unit 13 functions as a misalignment width setting means.
The display unit 14 displays an operation screen or the like according to the instructions of the control unit 11. As the display unit 14, an LCD (Liquid Crystal Display), an OLED (Organic Electro Luminescence Display), or the like can be used.

The communication unit 15 transmits / receives data to / from an external device connected to the communication network. For example, the communication unit 15 receives data (PDL data) in which the instruction content for forming an image is described in a page description language (PDL) from an external device.

The image generation unit 16 rasterizes the PDL data received by the communication unit 15 and generates image data in bitmap format. This image data is composed of four colors of C (cyan), M (magenta), Y (yellow) and K (black), and each pixel has a pixel value of four colors. The pixel value is a data value representing a shade of an image, and for example, an 8-bit data value represents a shade of 0 to 255 gradations.

The scanner unit 17 reads the original surface and generates image data in bitmap format having pixel values of each of R (red), G (green), and B (blue). This image data may be converted into image data of each of the four colors of CMYK by a color conversion unit or the like.

The image memory 18 is a buffer memory that temporarily holds the image data generated by the image generation unit 16 or the scanner unit 17. As the image memory 18, a DRAM (Dynamic RAM) or the like can be used.

The image processing unit 19 reads image data from the image memory 18 and performs various image processing such as density correction processing, color correction processing, and halftone processing.

The image forming unit 20 forms an image composed of four colors of CMYK on the recording medium according to the pixel values of the four colors of each pixel of the image data image-processed by the image processing unit 19.
As shown in FIG. 1, the image forming unit 20 includes four writing units 21, an intermediate transfer belt 22, a secondary transfer roller 23, a fixing device 24, a paper feed tray 25, and an inversion path 26.

The four writing units 21 are arranged in series (tandem) along the belt surface of the intermediate transfer belt 22 to form an image of each color of CMYK on the intermediate transfer belt 22. Each writing unit 21 has the same configuration except that the color of the image to be formed is different, and as shown in FIG. 1, the exposed unit 2a, the photoconductor 2b, the developing unit 2c, the charging unit 2d, the cleaning unit 2e, and the primary unit 21 are used. A transfer roller 2f is provided.

At the time of image formation, in each writing unit 21, after charging the photoconductor 2b by the charging unit 2d, the light beam emitted by the exposed unit 2a scans the photoconductor 2b based on the image data to form an electrostatic latent image. do. When a color material such as toner is supplied by the developing unit 2c for development, an image is formed on the photoconductor 2b.
The images formed on the photoconductors 2b of the four writing units 21 are sequentially superimposed and transferred (primary transfer) on the intermediate transfer belt 22 by the respective primary transfer rollers 2f. As a result, an image composed of each color is formed on the intermediate transfer belt 22. After the primary transfer, the cleaning unit 2e removes the coloring material remaining on the photoconductor 2b.

The image forming unit 20 supplies a recording medium from the paper feed tray 25, transfers an image from the intermediate transfer belt 22 onto the recording medium (secondary transfer) by the secondary transfer roller 23, and then transfers the recording medium to the recording medium by the fixing device 24. It is heated and pressurized to perform fixing treatment.
When an image is formed on both sides of the recording medium, the recording medium is conveyed to the inversion path 26, the front and back sides of the recording medium are inverted, and then the recording medium is conveyed to the secondary transfer roller 23 again.

As shown in FIG. 1, the image reading unit 30 is arranged on the transport path of the recording medium, and the image forming unit 20 reads the recording medium on which the image is formed and generates the scanned image data. As the image reading unit 30, a line sensor in which a sensor such as a CCD (Charge Coupled Device) is arranged one-dimensionally, an area sensor or the like arranged in two dimensions can be used.

When the cutting process is set, the cutting unit 40 cuts the peripheral portion of the conveyed recording medium at a preset position. The cutting unit 40 may cut the recording media one by one, or may cut a plurality of recording media together.

As shown in FIG. 2, the inspection unit 50 includes a correct answer information acquisition unit 51, an alignment unit 52, a misalignment determination unit 53, and the like.
The processing content of each part of the inspection unit 50 can be realized by hardware processing using an image processing circuit such as an ASIC (Application Specific Integrated Circuit) or FPGA (Field-Programmable Gate Array), or can be realized by a CPU or GPU (Graphics). It can also be realized by software processing such as Processing Unit) that reads and executes the program.

The correct answer information acquisition unit 51 acquires the correct answer information stored in the storage unit 12 when the image inspection process described later is executed. When the correct answer information is stored outside, the correct answer information acquisition unit 51 acquires the correct answer information from the outside via the communication unit 15.
That is, the correct answer information acquisition unit 51 functions as a correct answer information acquisition means.

The alignment unit 52 aligns the inspection image of the scanned image data acquired by the image reading unit 30 reading the final printed matter with the composite image of the composite image data.
Specifically, the alignment unit 52 extracts edge coordinate positions or marker coordinate positions, which are feature points existing in each image data, from the composite image data and the read image data, and aligns the feature points with each other. ..
The edge coordinate position is extracted by scanning on the composite image data and the read image data.
The marker coordinate position is prepared in advance so that the alignment marker is printed at the same position on the composite image data and the recording medium, and is extracted by scanning on the composite image data and the read image data. ..
That is, the alignment unit 52 functions as an alignment means.

The misalignment determination unit 53 determines the occurrence of misalignment from the comparison between the read image data and the composite image data.
Specifically, the misalignment determination unit 53 detects the inspection boundary portion on the inspection image based on the boundary portion position information. That is, the misalignment determination unit 53 functions as a boundary portion detecting means.
Next, the misalignment determination unit 53 develops a window containing boundary portion position information on the composite image data and the read image data with the same size and the same phase coordinates as the base point.
Next, the misalignment determination unit 53 compares the boundary portion of the composite image data and the inspection boundary portion of the read image data in the above window, and there is a difference in the comparison result of the pixel values on the boundary portion position information. In this case, the coordinate position is stored in the storage unit 12 as a candidate for the occurrence of misalignment.
Next, the misalignment determination unit 53 determines whether the coordinate positions of the misalignment occurrence candidates have continuity based on the boundary portion position information.
Next, the misalignment determination unit 53 calculates the misalignment width in the direction perpendicular to the direction information of the boundary portion position information.
Next, the misalignment determination unit 53 finally determines that the misalignment has a problem with respect to the quality of the printed matter when the calculated misalignment width exceeds the threshold value even at one place. That is, the misalignment determination unit 53 functions as a misalignment detecting means.

The control unit 11, the storage unit 12, and the inspection unit 50 realize the function as the image inspection device 1000.

After the image is formed, the recording medium is discharged to the output tray T1 or the output tray T2 shown in FIG.

(Operation of image forming apparatus 1)
Next, the operation of this embodiment will be described.
FIG. 3 shows a flowchart of an image inspection process executed by the image forming apparatus 1. The image inspection process is executed in collaboration with the program stored in the control unit 11 and the storage unit 12.

First, the control unit 11 receives the pre-printed image data and the reprint print image data designated in association with each other via the communication unit 15 (step S1).
Next, the control unit 11 synthesizes the pre-printed image data and the reprint print image data to create the composite image data. Then, the control unit 11 stores the composite image data in the storage unit 12 (step S2). The control unit 11 may receive the composite image data created in advance from the outside via the communication unit 15.
Here, the upper left figure of FIG. 4 is an example of an individual image of the pre-printed image data, and the upper right figure is an example of an individual image of the reprint print image data. The composite image data shown in the lower left figure is created from these data.

Next, the control unit 11 extracts the edge information in the pre-printed image data and the reprint print image data. The control unit 11 may extract the edge information based on the vector data embedded in each image data. Further, the control unit 11 may perform edge determination by scanning each RIP image data with a small window for extraction, or may output each image data to be combined in advance and output an image reading unit. Extraction may be performed by performing edge determination by scanning the image area read in No. 30.
The control unit 11 stores edge information adjacent to the image data to be combined as a boundary portion, and stores the coordinate position of the boundary portion on the composite image data in the storage unit 12 as the boundary portion position information (step S3).
Here, the lower right figure of FIG. 4 is the boundary portion position information which is the coordinate position on the composite image data of the boundary portion.

Next, the control unit 11 determines the directionality of the boundary portion from the angle of the boundary portion based on the boundary portion position information, and stores the direction information in the storage unit 12 (step S4).
Here, FIG. 5 is an example of direction information. For example, the control unit 11 determines that the directionality of the boundary portion parallel to the x-axis shown in the lower right of FIG. 5 is the horizontal direction, and the directionality of the other boundary portions is the vertical direction.
The threshold value for determining the horizontal direction and the vertical direction is set in advance, and the threshold value is not limited to this example. For example, the lateral direction may be determined from an angle parallel to the x-axis to a predetermined angle.

The control unit 11 controls the image forming unit 20 to perform pre-printing on the recording medium (step S5).
Next, the control unit 11 controls the image forming unit 20 and starts additional printing on the printed matter preprinted in step S5 (step S6).
Next, the control unit 11 uses the image reading unit 30 to perform additional printing to read the final printed matter on which the inspection image is formed, and acquires the scanned image data (step S7).

The alignment unit 52 aligns the inspection image of the read image data acquired in step S7 with the composite image of the composite image data acquired by the correct answer information acquisition unit 51 (step S8). Examples of edge coordinate positions and marker coordinate positions, which are feature points used for alignment, are shown in FIGS. 6A and 6B.
FIG. 6A is a case where the edge coordinate position is used as the feature point, and FIG. 6B is a case where the marker coordinate position is used as the feature point.
In addition, position correction by shift or scaling to match the feature points of the composite image and the inspection image is performed on the composite image data side.

The misalignment determination unit 53 detects the inspection boundary portion where the boundary portion on the inspection image is located, based on the boundary portion position information acquired by the correct answer information acquisition unit 51 (step S9).
Next, the misalignment determination unit 53 expands an m × n (m ≧ 1, n ≧ 1) window containing the boundary portion position information on the composite image data and the read image data with the same size and the same phase coordinates as the base point. (Step S10).
FIG. 7 is an expanded view of a 4 × 4 window.

Next, the position shift determination unit 53 unifies the color space between the composite image data and the read image data, and compares the pixel values on the boundary portion position information between the composite image data and the read image data in the window.
In FIG. 7, there are places where the pixel values are different between the left window, which is the window on the composite image data, and the right window, which is the window on the scanned image data.
When the difference in the comparison result of the pixel values is equal to or greater than a predetermined threshold value, the misalignment determination unit 53 determines that the candidate is a candidate for misalignment, and stores the coordinate position of the candidate location for misalignment in the storage unit 12 (. Step S11).
The misalignment determination unit 53 carries out step S11 for all inspection boundary portions.

Next, the misalignment determination unit 53 evaluates whether or not the coordinate positions of the misalignment occurrence candidates have continuity based on the boundary portion position information (step S12).
FIG. 8 is a diagram in which a position shift occurrence candidate location exists along the boundary portion. In this case, the misalignment determination unit 53 determines that the coordinate positions of the misalignment occurrence candidates have continuity based on the boundary portion position information.

Next, the misalignment determination unit 53 calculates the misalignment width of the misalignment occurrence candidate location determined to have continuity in step S12 (step S13).
In the calculation method, the continuous length of the candidate coordinate positions where the misalignment occurs is obtained in the direction perpendicular to the direction information acquired by the correct answer information acquisition unit 51, and is used as the misalignment width.
In FIG. 8, since the direction of the boundary portion where the white arrow is described is the vertical direction, the continuous length of the coordinate positions of the candidate for misalignment is obtained in the direction perpendicular to the vertical direction, that is, in the horizontal direction. .. The length is indicated by the length of the white arrow.

Next, the misalignment determination unit 53 determines whether or not all the misalignment widths calculated in step S13 are equal to or greater than the threshold value of the misalignment amount (step S14). If even one misalignment width is equal to or greater than the threshold value (step S14; YES), it is determined that a misalignment having a quality problem has occurred, and the process proceeds to step S15.
When automatic stop is set by the operation unit 13 in step S15 (step S15; YES), the control unit 11 automatically stops printing (image forming operation) in order to investigate the problem (step S16). ..
The threshold value for the amount of misalignment is preset by the user by the operation unit 13.

Further, when the operation unit 13 is set to eject the printed matter in which the misalignment has occurred to a tray different from the printed matter in which the misalignment has not occurred (step S17; YES), the control unit 11 has set. The output tray is switched from the output tray T1 to the output tray T2 (step S18), the recording medium after image formation is discharged to the output tray T2 of FIG. 1, and the process is completed.

Further, when all the misalignment widths calculated in step S13 are less than the threshold value of the misalignment amount (step S14; NO) and when automatic stop is not set (step S15; NO), the control unit 11 , The reprint printing is continued (step S19), and the process is terminated.
Further, when it is not set to eject the printed matter in which the misalignment has occurred to a tray different from the printed matter in which the misalignment has not occurred (step S17; NO), the control unit 11 has a normal paper ejection tray. The recording medium after image formation is ejected to (paper ejection tray T1) (step S20), and the process is completed.

As described above, the image inspection device 1000 detects the positional deviation between the individual images in the inspection image obtained by forming individual images based on a plurality of image data at different timings on the same recording medium. The inspection device 1000 includes a correct answer information acquisition means (correct answer information acquisition unit 51) for acquiring correct answer information including composite image data of a plurality of image data and position information of a boundary portion of adjacent individual images, and composite image data. The inspection boundary portion is detected based on the position information of the boundary portion from the alignment means (alignment unit 52) for aligning the scanned image data obtained by reading the inspection image formed on the recording medium and the scanned image data. By comparing the pixel values of the boundary portion detecting means (positional deviation determination unit 53) and the inspection boundary portion of the read image data with the boundary portion of the composite image data, the positional deviation between the individual images in the inspection image is detected. A misalignment detecting means (misalignment determination unit 53) is provided.
Therefore, it is possible to automatically detect the positional deviation between the individual images in the inspection image obtained by forming and synthesizing the individual images based on the plurality of image data on the storage medium at different timings.

Further, the boundary portion position information includes edge information of a plurality of image data.
Therefore, it is possible to accurately acquire the boundary portion to be inspected for the misalignment.

Further, the image inspection device 1000 includes a position shift width setting means (operation unit 13) for setting a position shift width to be detected.
Therefore, it is possible to detect the misalignment with the amount of misalignment arbitrarily set by the user.

Further, when the image forming apparatus 100 detects the misalignment, the recording medium on which the inspection image in which the misalignment has occurred is formed is different from the recording medium in which the inspection image in which the misalignment has not occurred is formed. A paper ejection control means (control unit 11) for ejecting paper to the tray is provided.
Therefore, the printed matter can be sorted according to the misalignment detection result.

Further, the image forming apparatus 100 includes a stop control means (control unit 11) that automatically stops the image forming operation when a positional deviation is detected.
Therefore, when the misalignment is detected, it is possible to avoid the output of the spoiled paper due to the misalignment.

The description in the above embodiment shows a suitable example of the image forming apparatus according to the present invention, and is not limited thereto.

Further, in the above embodiment, the image inspection device is provided in the image forming device, but the present invention is not limited to this. The image inspection device may be a device separate from the image forming device including the image forming unit.

In addition, the detailed configuration and detailed operation of the image forming apparatus 100 can be appropriately changed without departing from the spirit of the present invention.

11 Control unit (paper ejection control means, stop control means)
12 Storage unit 13 Operation unit (positional deviation width setting means)
14 Display unit 20 Image forming unit 30 Image reading unit (reading unit)
40 Cutting department 50 Inspection department 51 Correct answer information acquisition department (correct answer information acquisition means)
52 Alignment part (alignment means)
53 Misalignment determination unit (boundary detection means, misalignment detection means)
100 Image forming device 1000 Image inspection device

Claims (10)

An image inspection device that detects positional deviations between individual images in an inspection image obtained by forming individual images based on a plurality of image data on the same recording medium at different timings and synthesizing them.
Correct answer information acquisition means for acquiring correct answer information including composite image data of a plurality of image data and position information of a boundary portion of adjacent individual images, and
An alignment means for aligning the composite image data and the read image data obtained by reading the inspection image formed on the recording medium, and
A boundary portion detecting means for detecting an inspection boundary portion based on the position information of the boundary portion from the read image data, and a boundary portion detecting means.
Positional deviation detection that detects the positional deviation between individual images in the inspection image by comparing the pixel values of the boundary portion of the composite image data and the inspection boundary portion of the read image data in the aligned state. Means and
Image inspection device equipped with. The image inspection device according to claim 1, wherein the position information of the boundary portion includes edge information of the plurality of image data. The correct answer information includes direction information indicating the directionality of the boundary portion.
The image inspection device according to claim 1 or 2, wherein the misalignment detecting means detects the misalignment based on the direction information. The image inspection apparatus according to any one of claims 1 to 3, further comprising a misalignment width setting means for setting a misalignment width to be detected. An image forming unit that forms the inspection image on a recording medium,
The image inspection device according to any one of claims 1 to 4, which inspects the inspection image formed by the image forming unit.
An image forming apparatus. The image forming apparatus according to claim 5, further comprising a reading unit for acquiring read image data obtained by reading an inspection image formed on a recording medium. When the misalignment is detected, the recording medium on which the inspection image in which the misalignment has occurred is discharged to a tray different from the recording medium in which the inspection image in which the misalignment has occurred is formed. The image forming apparatus according to claim 6, further comprising a paper ejection control means. The image forming apparatus according to claim 6 or 7, further comprising a stop control means for automatically stopping the image forming operation when the misalignment is detected. It is an image inspection method for detecting a positional deviation between individual images in an inspection image obtained by forming individual images based on a plurality of image data on the same recording medium at different timings and synthesizing them.
A correct answer information acquisition step for acquiring correct answer information including composite image data of a plurality of image data and position information of a boundary portion of adjacent individual images, and
An alignment step for aligning the composite image data and the read image data obtained by reading the inspection image formed on the recording medium, and
A boundary portion detection step for detecting an inspection boundary portion based on the position information of the boundary portion from the read image data, and a boundary portion detection step.
Positional deviation detection that detects the positional deviation between individual images in the inspection image by comparing the pixel values of the boundary portion of the composite image data and the inspection boundary portion of the read image data in the aligned state. Steps and
Image inspection method including. A computer of an image inspection device that detects a positional deviation between individual images in an inspection image obtained by forming individual images based on a plurality of image data on the same recording medium at different timings and synthesizing them.
Correct answer information acquisition means for acquiring correct answer information including composite image data of a plurality of image data and position information of a boundary portion of adjacent individual images.
An alignment means for aligning the composite image data and the scanned image data obtained by reading the inspection image formed on the recording medium.
A boundary portion detecting means for detecting an inspection boundary portion from the read image data based on the position information of the boundary portion.
Positional deviation detection that detects the positional deviation between individual images in the inspection image by comparing the pixel values of the boundary portion of the composite image data and the inspection boundary portion of the read image data in the aligned state. means,
A program to function as.

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