JP6717286B2 - Image inspection apparatus, image inspection method, and image inspection apparatus control program - Google Patents

Description

The present invention relates to an image inspection device, an image inspection method, and a control program for the image inspection device, and more particularly, to setting a threshold for determining a defect in an image when inspecting the image.

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

However, plateless printing devices such as electrophotography, which have become widespread in recent years, are good at printing a small number of prints, and in many cases, different pages have different print contents, such as variable printing. Then, it is inefficient to make a comparison. In order to deal with this problem, it is possible to generate a master image from print data. This makes it possible to efficiently handle variable printing.

In such an image inspection process, the degree of the difference described above, that is, the position of the image read from the output paper and the master image generated from the print data are aligned and the size is adjusted. By setting a predetermined threshold value for the result of comparing the images for each pixel, it is determined whether or not the printed matter is defective.

As a technique for verifying the inspection accuracy in such image inspection, defects that are likely to occur when using an inkjet printer are pseudo-printed, and the inspection results of the paper on which the pseudo-defects are printed are verified. By doing so, a method of verifying whether or not an appropriate inspection has been proposed has been proposed (for example, refer to Patent Document 1).

Since the setting of the threshold value for the image comparison result described above relates to the accuracy of the inspection, it is necessary to set an appropriate threshold value in order to perform the highly accurate inspection. The technique disclosed in Patent Document 1 is for determining whether or not the inspection is properly performed, including the threshold value that has already been set. Therefore, in order to set an appropriate threshold value, it is necessary for the user to change the threshold value and perform inspection many times to confirm whether the inspection is properly performed.

The present invention has been made in view of the above circumstances, in the inspection of the image by comparing the image read the output result of the image forming output and the master image, the threshold value for determining the defect based on the comparison result. The purpose is to easily and suitably set.

In order to solve the above problems, one embodiment of the present invention includes a reading device, and forms on the recording medium based on a read image generated by reading an image formed and output on the recording medium by the reading device. An image inspection apparatus having an image inspection unit for inspecting a defect of the formed image, the image including a reference pattern, and the image is arranged in each of a predetermined direction and a direction orthogonal to the predetermined direction. Different from the image including the reference pattern formed on the recording medium based on the read image obtained by reading the recording medium on which the image in which the pseudo defect is added to the plurality of marks is formed by the reading device. comprising a threshold determiner, wherein the image inspecting unit against the image to determine the threshold used when performing the test, the pseudo-defect, the predetermined direction, or in at least one direction of the direction the perpendicular A width is provided, and the width is different for each of the marks arranged in each of the predetermined direction or the orthogonal direction .

Further, another aspect of the present invention includes a reading device, and based on a read image generated by reading an image formed and output on the recording medium by the reading device, an image formed on the recording medium is displayed. An image inspection method executed in an image inspection apparatus having an image inspection unit for inspecting a defect and a threshold determination unit, wherein the threshold determination unit is an image including a reference pattern, and has a predetermined direction and a predetermined direction. based on the a direction orthogonal to the direction of the scanned image placed multiple marks pseudo defects the said recording medium on which an image is formed by adding a reader to have read to each, on the recording medium The image inspection unit determines a threshold value used when performing the inspection on an image different from the image including the reference pattern , and the pseudo defect is the predetermined direction or the orthogonal direction. It has a width in at least one of the directions, and the width is different for each of the marks arranged in the predetermined direction or the orthogonal direction .

Still another aspect of the present invention includes a reading device, and an image formed on the recording medium based on a read image generated by reading an image image-outputted on the recording medium by the reading device. Is a control program of an image inspection apparatus having an image inspection unit for inspecting defects, and is an image including a reference pattern , and is arranged in each of a predetermined direction and a direction orthogonal to the predetermined direction. Different from the image including the reference pattern formed on the recording medium based on the read image obtained by reading the recording medium on which the image in which the pseudo defect is added to the plurality of marks is formed by the reading device. The image inspection apparatus is caused to execute a step of determining a threshold value used when the image inspection unit performs the inspection on the image, and the pseudo defect is at least in the predetermined direction or in the orthogonal direction. It has a width in one direction, and the width is different for each of the marks arranged in each of the predetermined direction or the orthogonal direction .

According to the present invention, in the image inspection by comparing the image obtained by reading the output result of the image forming output with the master image, the threshold value for judging the defect based on the comparison result is easily and suitably set. be able to.

FIG. 1 is a diagram showing a configuration of an image forming system including an inspection device according to an embodiment of the present invention. It is a block diagram which shows the hardware constitutions of the inspection apparatus which concerns on embodiment of this invention. It is a block diagram showing functional composition of an engine controller, a print engine, and an inspection device concerning an embodiment of the present invention. It is a figure which shows the mechanical structure of the print processing part which concerns on embodiment of this invention. It is a block diagram which shows the functional structure of the master image processing part which concerns on embodiment of this invention. 6 is a flowchart showing a threshold value determining operation according to the embodiment of the present invention. It is a figure which shows the example of the image output in the threshold value determination operation which concerns on embodiment of this invention. It is a figure which shows the setting aspect of the pseudo defect which concerns on embodiment of this invention. It is a figure which shows the example of the individual threshold value calculated about each of the some pseudo defect which concerns on embodiment of this invention. 6 is a flowchart showing an operation of calculating an individual threshold value according to the embodiment of the present invention. It is a figure which shows the example of the threshold value selection screen which concerns on embodiment of this invention. It is a figure which shows the other example of the threshold value selection screen which concerns on embodiment of this invention. It is a figure which shows the structure of the system which concerns on other embodiment of this invention. It is a figure which shows the structure of the system which concerns on other embodiment of this invention. It is a chart. It is a figure which shows the aspect of the comparison inspection of the image which concerns on embodiment of this invention. It is a figure which shows the example of the threshold value setting which concerns on embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, in the image forming system including the inspection device that inspects the output result by comparing the image obtained by reading the output result of the image forming output and the master image, in order to determine the defect of the image based on the comparison result. A process for easily and preferably setting the threshold according to the inspection accuracy intended by the user will be described as a feature.

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

The engine controller 2 controls the print engine 3 based on the bitmap data received from the DFE 1 to execute image forming output. Further, the engine controller 2 according to the present embodiment serves as a source of an inspection image for referring to the bitmap data received from the DFE 1 when the inspection device 4 inspects the result of the image forming output by the print engine 3. The information is transmitted to the inspection device 4.

Under the control of the engine controller 2, the print engine 3 performs image forming output on a sheet that is a recording medium based on the bit map data, and inspects the read image data generated by reading the output sheet with a reading device. Input to the device 4. Incidentally, as the recording medium, in addition to the above-described paper, a sheet-shaped material such as a film or plastic, which is an object of image forming output, can be adopted. The inspection device 4 generates a master image based on the bitmap data input from the engine controller 2. The inspection device 4 is an image inspection device that inspects the output result by comparing the read image input from the print engine 3 with the generated master image.

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

As shown in FIG. 2, the inspection device 4 according to the present embodiment has the same configuration as an information processing device such as a general PC (Personal Computer) or a server. That is, in the inspection device 4 according to the present embodiment, a CPU (Central Processing Unit) 10, a RAM (Random Access Memory) 20, a ROM (Read Only Memory) 30, an HDD (Hard Disk Drive) 40, and an I/F 50 are a bus 90. Connected through. Further, an LCD (Liquid Crystal Display) 60, an operation unit 70, and a dedicated device 80 are connected to the I/F 50.

The CPU 10 is a calculation means and controls the operation of the inspection device 4 as a whole. The RAM 20 is a volatile storage medium that can read and write information at high speed, and is used as a work area when the CPU 10 processes information. The ROM 30 is a read-only non-volatile storage medium, and stores programs such as firmware. The HDD 40 is a non-volatile storage medium capable of reading and writing information, and stores an OS (Operating System), various control programs, application programs, and the like.

The I/F 50 connects and controls the bus 90 and various hardware and networks. The LCD 60 is a visual user interface for the user to confirm the state of the inspection device 4. The operation unit 70 is a user interface such as a keyboard and a mouse for the user to input information to the inspection device 4.

The dedicated device 80 is hardware for realizing a dedicated function in the engine controller 2, the print engine 3, and the inspection device 4, and in the case of the print engine 3, a plotter device that executes image forming output on a paper surface or A reading device that reads an image output on a sheet of paper. Further, the engine controller 2 and the inspection device 4 are dedicated arithmetic devices for performing high-speed image processing. Such a computing device is configured as, for example, an ASIC (Application Specific Integrated Circuit).

In such a hardware configuration, a program stored in a recording medium such as the ROM 30, the HDD 40, or an optical disk (not shown) is read into the RAM 20, and the CPU 10 performs an operation according to the program, thereby configuring a software control unit. It A combination of the software control unit configured in this way and hardware constitutes a functional block that implements the functions of the engine controller 2, the print engine 3, and the inspection device 4 according to the present embodiment.

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

The data acquisition unit 201 acquires the bitmap data input from the DFE 1 and operates the engine control unit 202 and the bitmap transmission unit 203, respectively. The bitmap data is information on each pixel that forms an image to be image-formed and output, and the data acquisition unit 201 functions as a pixel information acquisition unit. The engine control unit 202 is an output execution control unit that causes the print engine 3 to execute image formation output based on the bitmap data transferred from the data acquisition unit 201. The bitmap transmission unit 203 transmits the bitmap data acquired by the data acquisition unit 201 to the inspection device 4.

The print processing unit 301 acquires the bitmap data input from the engine controller 2, executes image forming output on the print paper, and outputs the printed paper. That is, the print processing unit 301 functions as an image forming apparatus. The print processing unit 301 according to the present embodiment is realized by a general electrophotographic image forming mechanism, but it is also possible to use another image forming mechanism such as an inkjet system. The reading device 302 reads the image formed on the paper surface of the printing paper that is printed by the print processing unit 301 and is output, and outputs the read data to the inspection device 4. The reading device 302 is, for example, a line scanner installed in a conveyance path of the printing paper output by the print processing unit 301, and scans the paper surface of the conveyed printing paper to read an image formed on the paper surface. ..

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

The plurality of image forming units 106BK, 106M, 106C, and 106Y have the same internal configuration except that the colors of toner images to be formed are different. The image forming unit 106BK forms a black image, the image forming unit 106M forms a magenta image, the image forming unit 106C forms a cyan image, and the image forming unit 106Y forms a yellow image. In the following description, the image forming unit 106BK will be specifically described, but the other image forming units 106M, 106C, and 106Y are the same as the image forming unit 106BK, and therefore the image forming units 106M, 106C, and 106Y. For each constituent element of BK, BK attached to each constituent element of the image forming unit 106BK
Instead of the above, the symbols distinguished by M, C, and Y are only shown in the drawing, and the description thereof is omitted.

The conveyor belt 105 is an endless belt spanned by a driving roller 107 and a driven roller 108 that are rotationally driven, that is, an endless belt. The drive roller 107 is rotationally driven by a drive motor (not shown), and the drive motor, the drive roller 107, and the driven roller 108 function as drive means for moving the conveyor belt 105, which is an endless moving means. ..

At the time of image formation, the first image forming unit 106BK transfers the black toner image to the conveyor belt 105 that is rotationally driven. The image forming unit 106BK includes a photoconductor drum 109BK as a photoconductor, a charger 110BK arranged around the photoconductor drum 109BK, an optical writing device 200, a developing device 112BK, a photoconductor cleaner (not shown), and a charge eliminator. It is composed of 113BK and the like. The optical writing device 200 is configured to irradiate each of the photoconductor drums 109BK, 109M, 109C, and 109Y (hereinafter, collectively referred to as “photoconductor drum 109”) with light.

During image formation, the outer peripheral surface of the photoconductor drum 109BK is uniformly charged by the charger 110BK in the dark, and then writing is performed by the light from the light source corresponding to the black image from the optical writing device 200, and the static writing is performed. A latent image is formed. Current image unit 112BK is the electrostatic latent image into a visible image by a black toner, a black toner image is formed on the photosensitive drum 109BK by this.

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

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

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

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

In the fixing device 116, the toner image transferred on the paper surface is fixed on the paper surface by heat. Therefore, the transfer paper passes through the high-temperature fixing device 116 to evaporate water, and the paper contracts, so that the image on the transfer paper becomes smaller than the original image. When the reading paper is read by the reading device 302, a read image smaller than the original image is generated.

In the case of double-sided printing, the sheet on which the image is fixed is conveyed to the reversing path, is reversed, and is conveyed to the transfer position again. The sheet on which the image is formed and fixed on one side or both sides is conveyed to the reading device 302. As a result, the reading device 302 takes an image of one side or both sides and generates a read image as an image to be inspected.

Next, each component of the inspection device 4 will be described with reference to FIG. 3 again. The read image acquisition unit 401 acquires information of a read image generated by the reading device 302 reading the paper surface of the printing paper in the print engine 3, and inputs the information to the comparison inspection unit 404 as an image to be inspected. The master image processing unit 402 acquires the bitmap data input from the engine controller 2 as described above, and generates a master image which is an inspection image for comparison with the inspection target image. That is, the master image processing unit 402 functions as an inspection image generation unit that generates a master image, which is an inspection image for inspecting the read image, based on the output target image. The master image generation processing by the master image processing unit 402 will be described in detail later.

The inspection control unit 403 is a control unit that controls the operation of the entire inspection device 4, and each component included in the inspection device 4 operates according to the control of the inspection control unit 403. Further, the inspection control unit 403 includes a threshold value determination master image generation control unit 403a, a threshold value determination comparative inspection control unit 403b, a threshold value determination processing unit 403c, and a UI control unit 403d as the configuration according to the gist of the present embodiment. The comparison inspection unit 404 compares the read image input from the read image acquisition unit 401 with the master image generated by the master image processing unit 402, and determines whether the intended image forming output is being performed. The image inspection unit is configured by the ASIC as described above in order to quickly process a huge amount of calculation.

Next, details of the functions included in the master image processing unit 402 will be described with reference to FIG. FIG. 5 is a block diagram showing the internal configuration of the master image processing unit 402. As shown in FIG. 5, the master image processing unit 402 includes a low-value multi-value conversion processing unit 421, a resolution conversion processing unit 422, a color conversion processing unit 423, and a master image output unit 424. The master image processing unit 402 according to the present embodiment is realized by the dedicated device 80 described in FIG. 2, that is, the hardware configured as an ASIC, operating under the control of software. The comparison inspection unit 404 and the master image processing unit 402 are configured by the ASIC as described above, but can be realized by a software module by the CPU 10.

The small-value/multi-value conversion processing unit 421 performs a small-value/multi-value conversion process on a binary image expressed in color/colorless to generate a multi-valued image. The bitmap data according to the present embodiment is information to be input to the print engine 3, and the print engine executes image forming output based on a binary image of each color of CMYK (Cyan, Magenta, Yellow, blacK). On the other hand, the read image, which is the image to be inspected, is a multi-valued image of multi-gradation of each color of RGB (Red, Green, Blue) which is the basic three primary colors, and therefore, the low-value multi-value conversion processing unit 421 first performs binary conversion. The image is converted to a multi-valued image. As a multi-valued image, for example, each of CMYK is 8
An image represented by bit can be used.

In the present embodiment, the case where the print engine 3 executes the image forming output based on the binary image of each color of CMYK is taken as an example, and the master image processing unit 402 includes the small-value multi-value conversion processing unit 421. , But this is an example. That is, when the print engine 3 executes image forming output based on a multi-valued image, the small-value multi-value conversion processing unit 421 can be omitted.

The resolution conversion processing unit 422 performs resolution conversion so that the resolution of the multi-valued image generated by the low-value multi-valued conversion processing unit 421 matches the resolution of the read image that is the image to be inspected. In the present embodiment, the reading device 302 generates a read image of 200 dpi, so the resolution conversion processing unit 422 converts the resolution of the multi-valued image generated by the small-value multi-valued conversion processing unit 421 into 200 dpi.

The color conversion processing unit 423 acquires the image whose resolution has been converted by the resolution conversion processing unit 422 and performs color conversion. As described above, since the read image according to the present embodiment is an image in the RGB format, the color conversion processing unit 423 converts the CMYK format image that has undergone resolution conversion by the resolution conversion processing unit 422 into the RGB format. .. As a result, a 200-dpi multi-valued image represented by 8 bits of RGB for each pixel (24 bits in total) is generated.

The master image output unit 424 outputs the master image generated by the low-value multi-value conversion processing unit 421, the resolution conversion processing unit 422, and the color conversion processing unit 423 to the inspection control unit 403. The inspection control unit 403 causes the comparison inspection unit 404 to perform image comparison processing based on the master image acquired from the master image processing unit 402, and acquires the comparison result.

In the comparison inspection unit 404, the read image of 200 dpi and the master image represented by 8 bits of each RGB color are compared for each corresponding pixel as described above, and the difference value of the pixel value of each 8 bits of each RGB color described above for each pixel. To calculate. Based on the magnitude relationship between the difference value calculated in this way and the threshold value, the comparison inspection unit 404 determines whether or not there is a defect in the read image. That is, the comparison inspection unit 404 functions as an image inspection unit that determines a defect in the read image based on the difference between the inspection image and the read image. Information in which the difference value calculated for each pixel is associated with each pixel position and formed in an image is called a “difference image”.

As a comparison method of the magnitude relationship between the difference value and the threshold value, the comparison inspection unit 404 sums the difference values calculated for the respective pixels for each predetermined range on the image, and compares the difference value with the threshold value set for the total value. Compare with the total value. The predetermined range in which the difference values of the respective pixels are totaled in this manner is, for example, a 20-dot square range. That is, the “threshold value” according to the present embodiment is a value provided for the sum of the difference values for the range in which such difference values are summed up (hereinafter referred to as “defect determination unit range”). .. Therefore, the comparison inspection unit 404 according to the present embodiment outputs, as the information indicating the presence or absence of a defect in the read image, the information of the position on the image of the defect determination unit range in which the sum of the difference values exceeds the threshold. As the information on the position on the image, for example, information on the coordinates on the image is used.

When comparing the read image and the master image, as shown in FIG. 15, the comparison inspection unit 404 superimposes the read image divided for each predetermined range on the master image corresponding to the divided range, and A pixel value, that is, a difference in density is calculated. Furthermore, while shifting the position where the divided range is superimposed on the master image vertically and horizontally, the position where the calculated difference value is the smallest is determined as the position of the accurate overlay, and the difference value calculated at that time is calculated. It is adopted as the comparison result. As shown in FIG. 15, each of the squares partitioned in a grid is the defect determination unit range described above.

Further, the above-mentioned "threshold value" is given to the comparison inspection unit 404 configured as an ASIC by register setting. That is, the inspection control unit 403 configured by the CPU 10 performing the calculation according to the program is provided for designating the threshold value set in the comparison inspection unit 404 as shown in FIG. By writing in the register, the above-mentioned "threshold value" is set.

As another method, first, it is determined whether each pixel is normal or defective based on the comparison result between the difference value calculated for each pixel and the threshold value, and the count value of the number of pixels determined to be defective and that There is a method of comparing with the threshold value set for.

In such a system, the gist of the present embodiment is to easily realize the setting of the threshold value according to the inspection accuracy intended by the user when the comparison inspection unit 404 sets the threshold value used in the above-described comparison processing. It is in. Therefore, in the present embodiment, each module included in the inspection control unit 403 determines the threshold value by using the function of each unit of the inspection device 4. The threshold setting operation according to this embodiment will be described below.

FIG. 6 is a flowchart showing the threshold setting operation according to the present embodiment. As shown in FIG. 6, in the threshold setting operation according to the present embodiment, the print engine 3 first prints the threshold determination image under the control of the engine controller 2 (S601). 7A to 7C are diagrams showing an example of the threshold value determination image according to the present embodiment. FIG. 7A shows a reference pattern 701 to which a pseudo defect is not added in the threshold value determination image according to the present embodiment, that is, a threshold value in which the normal state of the image for determining the threshold value is displayed. It is a figure which shows the normal image for determination. As shown in FIG. 7A, the reference pattern 701 according to this embodiment is formed by drawing marks of a predetermined color in the horizontal direction, that is, in four columns in the X direction and in the vertical direction, that is, in five rows in the Y direction. Has been done. The image shown in FIG. 7A is output from the print engine 3 as the first image under the control of the engine controller 2.

On the other hand, the images shown in FIGS. 7B and 7C are defect images for threshold determination in which a plurality of pseudo defects having different degrees are added to the normal image for threshold determination. FIG. 7B is an image in which pseudo defects having different color densities are added to the above-described reference pattern in the threshold value determination image according to the present embodiment (hereinafter referred to as density change defect pattern 702). FIG. As shown in FIG. 7B, the density change defect pattern 702 is an image in which pseudo defects having different aspects are added to the respective marks arranged in the X direction and the Y direction. The image shown in FIG. 7B is output as the second image from the print engine 3 under the control of the engine controller 2.

Here, in the density variation defect pattern according to the present embodiment, pseudo defects of different colors are added to the respective marks arranged in the X direction, and different densities are applied to the respective marks arranged in the Y direction. Is added. That is, the image shown in FIG. 7B is an image to which a plurality of pseudo defects having different colors and different degrees are added. FIG. 8 is information (hereinafter, density change defect pattern information) referred to by the engine control unit 202 of the engine controller 2 when the density change defect pattern shown in FIG. 7B is output. The density change defect pattern information of FIG. 8 is stored in a storage medium such as the RAM 20, the ROM 30, the HDD 40, or the like that configures the engine control unit 202, or an external storage medium.

In FIG. 8, “PC”, “PM”, “PY”, and “PK” are values indicating pattern colors for each of CMYK colors. As shown in FIG. 8, in the density change defect pattern information, information on the color of the pseudo defect to be added is set for each pattern of 4 columns in the X direction and 5 rows in the Y direction. For example, “d1” is added to “PC” for the pattern in the first row and first column, and the colors having the same values as those of the pattern are added as pseudo defects for the other MYK. Then, by adding values to "PM" in the second column, "PY" in the third column, and "PK" in the fourth column, a pseudo defect of a color different from the original pattern is added. Will be done.

Further, as shown in FIG. 8, in the Y direction, the value to be added changes like “+d1”, “+d2”, “+d3”. Here, in the present embodiment, the larger the value of n of “dn”, the higher the density. That is, in the Y direction, the density of the color for which a value is added as a pseudo defect is high. In FIG. 7B, the change in the density is represented by a difference in the form of lines such as a dotted line and a broken line.

Here, at the time of outputting the density change defect pattern as shown in FIG. 7B, the engine control unit 202 acquires the setting of the range in which the density is changed, and based on the acquired setting of the range, it is shown in FIG. Determine the value of "dn". The setting of this range may be a value set in advance for the engine control unit 202, or may be manually set by the user when outputting the density change defect pattern.

When the lower limit of the set value of the above range is “dm” and the upper limit is “dM”, “dn” can be obtained by the following formula (1).
The range from "dm" to "dM" is equally divided by the five values "d1" to "d5" by the calculation of the above formula (1) and is used as the added value of the density.

FIG. 7C is an image in which pseudo defects having different line widths are added to the above-described reference pattern in the threshold value determination image according to the present embodiment (hereinafter, referred to as width change defect pattern 703). FIG. As shown in FIG. 7C, in the width change defect pattern 703, similar to the density change defect pattern 702, an image in which pseudo defects having different aspects are added to the respective marks arranged in the X direction and the Y direction. Is. That is, the image shown in FIG. 7C is also an image to which a plurality of pseudo defects having different colors and degrees are added, as in FIG. 7B. The image shown in FIG. 7C is output as the third image from the print engine 3 under the control of the engine controller 2. In the width change defect pattern 703, similar to the density change defect pattern 702, pseudo defects of different colors are added to the respective marks arranged in the X direction. Pseudo defects having different widths are added to the respective marks arranged in the Y direction.

The engine control unit 202 also changes the width of the pseudo defect between the set ranges in the same manner as the density change defect pattern, even when the width of the pseudo defect shown in FIG. 7C is changed. Such a change in width is possible by obtaining the width of the pseudo defect as "dn" by the same calculation as in the above formula (1). The engine control unit 202 stores the “dn” calculated in this way for use in the subsequent processing.

Note that, in the present embodiment, the case where the engine control unit 202 generates bitmap data for executing the image forming output of the patterns shown in FIGS. 7A to 7C is taken as an example. The DFE 1 may have such a function.

When the process of S601 is executed in this way, the engine controller 2, the print engine 3, and the inspection device 4 execute the respective processes as described above, and the bitmap data is transmitted from the engine controller 2 to the inspection device 4. At the same time, in the print engine 3, the read image of the output sheet is generated by the reading device 302 and input to the inspection device 4. On the other hand, the inspection device 4 in the threshold setting operation generates the master image based on the bitmap data of the first image among the bitmap data input from the engine controller 2 (S602a), and the second image. The read image of the image and the third image is acquired (S602b).

In S602a, the threshold determination master image generation control unit 403a of the inspection control unit 403 controls the master image processing unit 402, and the first of the bitmap data of the first image to the third image input from the engine controller 2 is input. Generate a master image for only the image. This master image is an inspection image for the normal image for threshold determination described above, that is, a normal inspection image.

Further, in step S602b, the threshold determination comparative inspection control unit 403b of the inspection control unit 403 controls the read image acquisition unit 401, and the first of the read images of the first image to the third image input from the print engine 3 is input. The read image of the image is discarded and the read images of the second image and the third image are acquired. This read image is a defect read image obtained by reading the above-described threshold determination defect image.

Then, the threshold value determination comparison inspection control unit 403b of the inspection control unit 403 controls the comparison inspection unit 404 to execute the comparison processing between the master image of the first image and the read images of the second and third images described above. Then, the difference value is calculated for each of the second image and the third image as described above, and the difference image is acquired (S603). In S603, the difference between the master image and the read image is calculated for each of a plurality of pseudo defects having different colors and degrees as shown in FIGS. 7B and 7C.

When the difference image from the master image is acquired for the second image and the third image, the threshold value determination processing unit 403c of the inspection control unit 403 arranges them in a matrix as described in FIGS. 7A to 7C. A threshold value for detecting a pseudo-added defect as a defect is calculated for each of the generated marks (S604). By the processing of S604, as shown in FIG. 9, the threshold value is calculated as "th11", "th12"... For each mark of 4 columns in the X direction and 5 rows in the Y direction. That is, in S604, a threshold value for determining each of the plurality of pseudo defects as a defect is calculated with respect to the difference generated for each of the plurality of pseudo defects having different colors and degrees. The respective threshold values calculated in this way are referred to as "individual threshold values". The information shown in FIG. 9 is stored in a storage medium such as the RAM 20, the ROM 30, the HDD 40, or the like that constitutes the inspection device 4, or an external storage medium.

Although one table is shown in FIG. 9, in the present embodiment, since individual threshold values are set for the respective marks included in the first image and the second image, the table shown in FIG. It is generated for each of the first image and the second image.

Here, details of the processing in S604 of FIG. 6 will be described with reference to FIG. As shown in FIG. 10, the threshold value determination processing unit 403c first sets an initial threshold value (S1001). This initial threshold value is a threshold value at which all defects are not extracted as defects. That is, as described above, a large value that is not judged as a defect even if the sum of all the difference values in the defect judgment unit range is large is set as the initial threshold value.

When the initial threshold value is set, the threshold value determination processing unit 403c controls the comparison inspection unit 303 according to the set threshold value to execute the defect determination processing (S1002). Here, in S1002, a defect determination process is performed for each area in which the respective marks shown in FIGS. 7A to 7C are displayed. On the other hand, in the normal defect determination process, the defect determination process is performed on the entire image. Therefore, since the number of target pixels is different between the determination of S1002 and the normal determination, the parameter of the calculated difference value is different. In order to deal with this change in the population parameter, the threshold value applied in S1002 uses a value adjusted according to the ratio of the pixel number of the entire image and the pixel number of the area where each mark is displayed. In addition, the initial threshold value set in S1001 may be a value corresponding to the number of pixels in the area where each mark is displayed.

As a result of the determination in S1002, if there is a region that is newly determined as a defect for each mark region (S1003/YES), the threshold determination processing unit 403c determines the currently set threshold as a new defect. The thresholds for the selected areas are set in the table shown in FIG. 9 (S1004). As a result, one threshold value such as “th11” or “th12” shown in FIG. 9 is set.

After the processing of S1004, the threshold value determination processing unit 403c confirms whether or not the threshold values have been set for all areas (S1005), and if all the threshold values have been set as shown in FIG. 9 (S1005/YES). , And ends the processing as it is. On the other hand, when there is no area newly determined as a defect as a result of the process of S1002 (S1003/NO) or when all thresholds are not set (S1005/NO), the threshold value determination processing unit 403c determines as a defect. The threshold value is changed so as to increase the possibility of being performed (S1006), and the processing from S1002 is repeated.

As described above, the threshold value determination processing unit 403c according to the present embodiment gradually changes the threshold value so that the possibility of being determined as a defect is increased, and repeats the defect determination process until all regions are determined as defects. .. As a result, as described with reference to FIGS. 7B and 7C, it is possible to determine a threshold value according to the actual defect determination process as a threshold value for extracting various pseudo defects having different degrees. Further, in the present embodiment, since the determination is made based on the read image generated by the reading device 302 at that timing, it is possible to set the threshold value according to the state of the reading device 302 in real time.

Note that, as described above, the threshold applied in S1002 is different from the threshold for determining the defect in the entire image. Therefore, when a value obtained by scaling the threshold value set at that time according to the number of pixels is used as the threshold value in S1002, the threshold value set in the table in S1004 is the threshold value set at that time point. On the other hand, when the threshold set at that time is used as the threshold in S1002, the threshold set in the table in S1004 is a value obtained by scaling the threshold set at that time according to the number of pixels. Is.

As the defect determination process, the ratio of the number of pixels whose difference value is a predetermined value or more to the total number of pixels is used as the information to be determined, and if the threshold is set as the ratio, that is, a percentage, the determination target It is possible to use the same threshold value regardless of the population of the pixels.

When the process of S604 is completed, the UI control unit 403d displays a GUI (Graphical User Interface) for allowing the user to set a threshold on the display device, and accepts the selection result according to the user's operation (S605). Here, the GUI displayed in S605 (hereinafter referred to as “threshold selection screen”) is shown in FIGS. The screens shown in FIGS. 11A and 11B are displayed on a display device such as the LCD 60 connected to the inspection device 4. FIG. 11A is a diagram showing an initial screen of the GUI displayed in S605, that is, a screen in a state where the user has not selected.

As shown in FIG. 11A, on the threshold selection screen, the images of the density change defect pattern and the width change defect pattern described in FIGS. 7B and 7C are displayed. Such an image can be displayed by, for example, the second image and the third image acquired by the read image acquisition unit 401. The user selects a mark to be identified as a defect on the screen as shown in FIG. 11(a).

When a mark is selected on the screen as shown in FIG. 11A, the user operates the screen, but the mark is selected not on the screen but on the output paper. As a result, it becomes possible to determine the defect in the state in which the paper is actually output. FIG. 11B is a diagram showing a state in which an image to be identified as a defect is selected by the user. As shown in FIG. 11B, the mark selected by the user is highlighted by being surrounded by a frame.

When the marks are thus selected, the UI control unit 403d acquires the selection result, and the threshold value determination processing unit 403c detects each mark as a defect by referring to the table described in FIG. It is possible to set the threshold of. That is, when the UI control unit 403d receives the user's selection in S605, the threshold value determination processing unit 403c displays the individual threshold value corresponding to the mark selected by the user from the table shown in FIG. 9 as shown in FIG. 11B. Extract. That is, the UI control unit 403d recognizes the defect selected by the user according to the operation on the screen as illustrated in FIG.

Specifically, when a defect is selected as shown in FIG. 11B, the threshold value determination processing unit 403c acquires information on the arrangement position of the selected defect on the image, and uses it as information on the arrangement position. Based on this, the "X direction arrangement" and "Y direction arrangement" of the table shown in FIG. 9 are specified. Then, the threshold value determination processing unit 403c extracts threshold value information corresponding to the placement position of the selected defect, such as "th11" and "th21" shown in FIG.

When the individual threshold for the selected mark is extracted from the table shown in FIG. 9 as shown in FIG. 11B, the threshold determination processing unit 403c determines a final threshold based on the extracted individual threshold (S606). ). In S606, the threshold value determination processing unit 403c determines the strictest value among the extracted individual threshold values, that is, the individual threshold values corresponding to the marks selected by the user to be determined to be defective, that is, more marks are determined to be defective. The individual threshold to be set is the final threshold. The threshold value thus determined is stored as the threshold value setting shown in FIG. 16, and when the comparison inspection unit 404 performs the image comparison inspection, the inspection control unit 403 writes the register value to the comparison inspection unit 404. To be

When the final threshold value is determined, the threshold value determination processing unit 403c determines whether readjustment is necessary based on the user's operation (S607). The contents of the operation by the user is acquired by the UI control unit 403 d. In S607, the threshold value determination processing unit 403c causes a display device such as the LCD 60 connected to the inspection device 4 to display a screen for selecting necessity of readjustment, and makes a determination according to a user operation on the screen. ..

If the readjustment is not necessary (S607/YES), the threshold value determination processing unit 403c ends the process as it is. On the other hand, when readjustment is necessary (S607/NO), the threshold value determination processing unit 403c notifies the engine controller 2 and controls the inspection device 4 so as to repeat the processing from S601. At this time, the threshold value determination processing unit 403c determines the maximum value of each individual threshold value extracted in S605 as the range in which the density and width are changed as described above in the density change defect pattern and the width change defect pattern, that is, dm and dM. And "dn" of the mark corresponding to the minimum value.

As described above, the “dn” calculated for each mark is stored in the storage medium such as the RAM 20, the ROM 30, the HDD 40, or the like forming the engine control unit 202, or an external storage medium. Therefore, the threshold value determination processing unit 403c merely notifies the engine control unit 202 of the position in the Y direction of the mark corresponding to the maximum value and the minimum value for each of the density change defect pattern and the width change defect pattern. It is possible to specify dn".

Note that in S605, individual threshold values are extracted for each of the density change defect pattern and the width change defect pattern. Therefore, the threshold value determination processing unit 403c specifies the mark "dn" corresponding to the maximum value and the minimum value of the individual threshold values extracted in S605 for each of the density change defect pattern and the width change defect pattern.

As a result, when the process of S601 is repeated, the mark with the pseudo defect in the range corresponding to the maximum value and the minimum value of the individual threshold values extracted by the process of S605 in the threshold value setting operation that has already been executed once is made. It is formed in the density change defect pattern and the width change defect pattern. By performing the processing of FIG. 6 on such a second image and a third image, it becomes possible to perform more detailed threshold setting.

As described above, in the system according to the present embodiment, the threshold value is changed stepwise for the image in which the defects of stepwise levels as shown in FIGS. By doing so, an individual threshold value that can detect each level of defects is obtained. Then, the user visually confirms the paper on which the pattern is drawn, selects a mark to be determined as a defect, and uses the individual threshold corresponding to the mark as a threshold to be set. By such processing, in the image inspection by comparing the image obtained by reading the output result of the image forming output with the master image, the threshold value for determining the defect based on the comparison result is easily and preferably set. It becomes possible.

It should be noted that, in the above-described embodiment, the case where the print output of the image as shown in FIGS. As a result, it becomes possible to change the range of the threshold value to be set and perform the repetitive processing, for example, like the processing of S607 in FIG. On the other hand, if it is not necessary to change the threshold value range and repeatedly execute the process, the bitmap data of the image shown in FIG. 7A is input to the master image processing unit 402, and at the same time, FIG. , (C), the above operation can also be realized by causing the reading device 302 of the print engine 3 to read the reading chart paper on which the image has already been formed.

Further, in the above embodiment, as shown in FIGS. 11A and 11B, the case where the second image and the third image are displayed on the screen and the user selects the mark has been described as an example. With such a screen, the selection of the mark by the user can be made more intuitive, but as shown in FIG. 12, the position of the mark in the X direction and the Y direction is selected in the list displayed as character information. Such a mode is also possible.

Further, in the above-described embodiment, as shown in FIGS. 7B, 7C, 11A, and 11B, in the density change defect pattern and the width change defect pattern, the respective marks are colored and pseudo. The case has been described as an example in which the images are arranged and displayed according to the degree of specific defects. This makes it possible to facilitate the selection of the allowable range according to the degree of the pseudo defect. In addition, it is possible to randomly arrange the color and the degree of the defect. This makes it possible to eliminate prejudice when the user selects a mark.

As described with reference to FIGS. 7B and 7C, in the density change defect pattern and the width change defect pattern according to this embodiment, a plurality of pseudo defects having different degrees are reproduced for each color of CMYK. Considering the human visual recognition characteristics of each color, it is possible that the degree of the pseudo defect determined to be acceptable by the user is different for each color.

For example, with respect to Y which is visually recognized relatively lightly, when up to the mark corresponding to “PY+d4” shown in FIG. 8 is allowed, that is, when only the mark corresponding to “PY+d5” is selected, K is It is possible that all the marks from the mark corresponding to "PK+d1" to the mark corresponding to "PK+d5" shown in FIG. In this case, as the threshold value, the threshold value for the mark corresponding to “PK+d1” becomes the strictest value. However, when this value is applied, the defect of Y color is also defective to the extent that the user judges that the defect should be allowed. Will be judged as.

In such a case, the comparison inspection unit 404 can improve the convenience for the user by setting a stepwise threshold value. Specifically, as the thresholds to be finally set, a first threshold value that is determined as a defect without confirming the user and a second threshold value that allows the user to select whether or not the defect is set are set. Is possible.

In such a case, in S605 of FIG. 6, the threshold determination processing unit 403c sets the strictest threshold as the threshold corresponding to the selected mark for each pseudo defect of each color, that is, for each column of the table shown in FIG. To extract. Then, the threshold value determination processing unit 403c sets, as the first threshold value, a value having the widest allowable range, that is, a value having the narrowest range to be determined as a defect, among the threshold values of the respective colors thus extracted, and the strictest. A value, that is, a value having the widest range to be determined as a defect is set as the second threshold.

By such a process, when it is determined as a defect even though the threshold value is the widest in the allowable range, it is highly likely that the defect is visually recognized by the user, and the defect is determined without inquiring the user. When it is determined as a defect by the threshold value having a narrow allowable range, it is not clear whether the defect is visually recognized by the user. Therefore, the accuracy of the defect determination can be improved by inquiring the user.

Further, as described in S607 of FIG. 6, when the threshold setting operation is repeatedly performed, the threshold determination processing unit 403c sets the value of “dn” corresponding to the above-described first threshold and second threshold to dm. , DM may be designated.

Further, in the above-described embodiment, as described with reference to FIGS. 11A, 11B, and S605 in FIG. 6, the user visually recognizes the pseudo defect and then selects the mark. The case where the final threshold value is determined based on the threshold value corresponding to the selected mark has been described as an example. Thereby, it is possible to easily set the tolerance in the defect determination based on the user's visual recognition.

On the other hand, even if there is no user's selection operation, normal images such as the first image shown in FIG. 7A and second and third images shown in FIGS. 7B and 7C are displayed. By setting the threshold value based on the difference from the image with the pseudo defect, it is possible to obtain the effect of setting the threshold value according to the state of the reading device 302. Therefore, even if the processing of S605 in FIG. 6 is omitted and the threshold value is automatically set based on the difference between the master image generated for the normal image and the read image of the image with the pseudo defect. good.

Further, in the above-described embodiment, as described with reference to FIG. 1, the case where the DFE 1, the engine controller 2, the print engine 3, and the inspection device 4 are respectively configured as separate devices has been described as an example. Here, among the respective configurations shown in FIG. 1, the DFE 1, the engine controller 2, and the print engine 3 have the corresponding functions even in a general image forming apparatus that is not an image forming apparatus for commercial printing. ..

Therefore, as shown in FIG. 13A, it is possible to connect the inspection device 4 to a printer which is a device equipped with functions corresponding to the DFE 1, the engine controller 2, and the print engine 3. Further, as shown in FIG. 13B, it is also possible to configure the printer as one device equipped with all the functions corresponding to the DFE 1, the engine controller 2, the print engine 3, and the inspection device 4.

Further, in the above-described embodiment, the DFE 1, the engine controller 2, the print engine 3, and the inspection device 4 are connected by a local interface such as a USB (Universal Serial Bus) or a PCIe (Peripheral Component Interconnect Express) to configure a system. The case has been described as an example. However, the inspection device 4 does not need to be installed at the same site as the DFE 1, the engine controller 2, and the print engine 3, and can be provided as an application that can be used via a network, for example.

FIG. 14 is a diagram showing an example in which the function of the inspection device 4 is provided via the network. In the example of FIG. 14, the engine controller 2 and the print engine 3 are connected to the inspection device 4 via a public line 5 such as the Internet. Then, the engine controller 2 and the print engine 3 transmit necessary information to the inspection device 4 via the public line 5. The inspection device 4 also transmits the inspection result to be notified to the engine controller 2 via the public line 5. With such a mode, it is not necessary to introduce the inspection device 4 into the user's base, and the user's initial cost can be reduced.

When the configuration shown in FIG. 14 is used, the function of the inspection device 4 is provided via the network, so that the user cannot directly control the inspection device 4. In such a case, the screens shown in FIGS. 11A, 11B, and 12 and the screens for controlling the other inspection devices 4 include a PC or the like connected to the network via a web browser or the like. By displaying the information on the information processing terminal, the user can use the system as described above.

Further, in the above embodiment, the case where the first, second, and third images are formed on different paper surfaces has been described as an example. The present invention is not limited to this, and a mode in which they are all formed on the same paper surface is also possible. In this case, the master image processing unit 402 extracts the range in which the first image is displayed and generates the master image. In addition, the read image acquisition unit 401 extracts the range in which the second and third images are displayed in the read image and sets it as the read image to be inspected.

Further, in the above-described embodiment, the case where the defect density and the defect range (the defect width in the above-described embodiment) are respectively changed as the degree of the pseudo defect has been described. This is an example, and it is conceivable that various other parameters may be changed as long as they are parameters related to the image. Further, instead of individually changing each parameter as in the above embodiment, changes of various parameters may be combined.

Further, in the above-described embodiment, when the threshold value determining operation is executed, the modules that function in the normal image inspection such as the master image processing unit 402 and the comparison inspection unit 404 are the threshold value determination master image generation control unit 403a and the threshold value determination module. An example will be described in which the threshold comparison processing unit 403c is controlled by the determination comparison inspection control unit 403b, and the threshold determination processing unit 403c and the UI control unit 403d operate based on the information obtained by the control to function as the threshold determination unit. did. This makes it possible to effectively use each module to simplify the device configuration, and because it is a module similar to a normal image inspection, it is possible to determine a threshold value under the same conditions as a normal image inspection. And is meaningful.

However, this is an example, and a master image generation module dedicated to the threshold value determination operation or an image comparison/inspection module may be provided. That is, a normal inspection image generation unit that generates a normal inspection image that is the inspection image for performing the inspection of the threshold determination normal image in which the normal state of the image for determining the predetermined threshold is displayed, A threshold determination comparison inspection unit may be provided that generates a difference between the defect read image obtained by reading the threshold determination defect image in which the defect is pseudo-added to the threshold determination normal image and the normal inspection image. ..

Further, in the above embodiment, the case where the threshold value determination processing unit 403c and the UI control unit 403d are provided as one configuration of the inspection control unit 403 has been described as an example. In addition, a module corresponding to the threshold value determination processing unit 403c or the UI control unit 403d may be provided as a module different from the inspection control unit 403.

1 DFE
2 engine controller 3 print engine 4 inspection device 10 CPU
20 RAM
30 ROM
40 HDD
50 I/F
60 LCD
70 Operation Unit 80 Dedicated Device 90 Bus 101 Paper Feed Tray 102 Paper Feed Roller 103 Separation Roller 104 Paper 105 Conveyor Belt 106BK, 106C, 106M, 106Y Image Forming Unit 107 Drive Roller 108 Driven Roller 109BK, 109C, 109M, 109Y Photosensitive Drum 110BK Charging device 111 Optical writing device 112BK, 112C, 112M, 112Y Developing device 113BK, 113C, 113M, 113Y Static eliminator 115BK, 115C, 115M, 115Y Transfer device 116 Fixing device 201 Data acquisition unit 202 Engine control unit 203 Bit map unit 301 Print processing unit 302 Reading device 401 Read image acquisition unit 402 Master image processing unit 403 Inspection control unit 403a Threshold determination master image generation control unit 403b Threshold determination comparison inspection control unit 403c Threshold determination processing unit 403d UI control unit 404 Comparison inspection unit 421 low-value multi-value conversion processing unit 422 resolution conversion processing unit 423 color conversion processing unit 424 master image output unit

JP, 2008-003876, A

Claims (7)

It has a reading device, and has an image inspection unit for inspecting defects of the image formed on the recording medium based on the read image generated by reading the image formed and output on the recording medium by the reading device. An image inspection device,
An image including a reference pattern , wherein the recording medium is formed with an image in which a pseudo defect is added to a plurality of marks arranged in a predetermined direction and a direction orthogonal to the predetermined direction. based on the reading device reads the read image, a threshold value by the image inspecting unit against the image different from the image including the reference pattern formed on the recording medium to determine the threshold used when performing the test Equipped with a decision unit ,
The pseudo defect has a width in at least one of the predetermined direction or the orthogonal direction,
The width is different for each of the marks arranged in each of the predetermined direction or the orthogonal direction,
An image inspection device characterized by the above. The image inspection device includes a display device that displays a read image obtained by reading the recording medium on which an image in which a pseudo defect is added to the reference pattern is formed, on a selection screen,
The image inspection apparatus according to claim 1, wherein the threshold value is determined based on a defect selected by a user from among defects on the read image displayed on the selection screen. The display device is
The read image is displayed on the selection screen so as to be arranged irregularly with respect to the degree of the pseudo defect.
The image inspection apparatus according to claim 2, wherein: The pseudo defect is a plurality of defects of different colors and degrees,
The threshold value determining unit obtains an individual threshold value for determining each of a plurality of pseudo defects having different colors and degrees as a defect,
Of the plurality of pseudo defects, the individual threshold value obtained for the defect selected for each different color is extracted for each different color,
Of the extracted individual threshold values for each different color, the value with the largest number of images determined as defects is set as the first threshold value, and the value with the smallest number of images determined as defects is set as the second threshold value. Then
The image inspection unit outputs a notification for allowing a user to confirm a result of the determination when the read image is determined to be a defect on the basis of the first threshold, and the image inspection unit outputs the notification. The image inspection device described. When the threshold value is determined again after determining the threshold value, when the threshold value is determined for the control unit that controls the output of the image in which the pseudo defect is added to the reference pattern on the recording medium. Based on the pseudo defect selected in, an image newly added with the pseudo defect to the reference pattern is output on a recording medium,
The image inspection apparatus according to any one of claims 2 to 4, wherein: An image inspection unit including a reading device and a threshold for inspecting a defect of an image formed on the recording medium based on a read image generated by reading an image formed and output on the recording medium by the reading device. An image inspection method executed in an image inspection apparatus having a determination unit, comprising:
The threshold value determining unit is an image including a reference pattern, and an image in which a pseudo defect is added to a plurality of marks arranged in each of a predetermined direction and a direction orthogonal to the predetermined direction is formed. Used when the image inspection unit performs the inspection on an image different from the image including the reference pattern formed on the recording medium based on the read image obtained by reading the recorded recording medium by the reading device. Determining the threshold value, the pseudo defect has a width in at least one of the predetermined direction or the orthogonal direction, the width is the predetermined direction or the orthogonal direction. Different for each of the marks placed on each of the
An image inspection method characterized by: It has a reading device, and has an image inspection unit for inspecting defects of the image formed on the recording medium based on the read image generated by reading the image formed and output on the recording medium by the reading device. A control program for an image inspection device,
An image including a reference pattern , wherein the recording medium is formed with an image in which a pseudo defect is added to a plurality of marks arranged in a predetermined direction and a direction orthogonal to the predetermined direction. Determining a threshold value used when the image inspection unit performs the inspection on an image different from the image including the reference pattern formed on the recording medium , based on the read image read by the reading device The image inspection apparatus is executed, the pseudo defect has a width in at least one direction of the predetermined direction or the orthogonal direction, the width is the predetermined direction, or the Different for each of the marks arranged in each of the orthogonal directions,
A control program for an image inspection device characterized by the above.