JP2018044882A - Image processing apparatus, image processing method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image processing apparatus, an image processing method and a program which are capable of accurately correcting uneven illumination occurring on a gloss image of a printed matter.SOLUTION: The image processing apparatus comprises: a reference gloss image acquisition unit 253 which acquires a reference gloss image representing gloss of a reference object, which is generated on the basis of light emitted from an illumination unit and reflected by the reference object; a calculation unit 255 which calculates a correction value for correcting uneven illumination on the basis of the reference gloss image; a modification unit 263 which modifies the correction value on the basis of a mapping property of the printed matter; a printed matter gloss image acquisition unit 265 which acquires a printed matter gloss image representing gloss of the printed matter, which is generated on the basis of light emitted from the illumination unit and reflected by the printed matter; and a correction unit 271 which corrects the printed matter gloss image on the basis of the modified correction value.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an image processing apparatus, an image processing method, and a program.

  In printing that requires high quality such as production printing, quality (defect) inspection is required for printed matter. For example, a printed matter inspection system that inspects the quality (presence or absence of defects) of the printed matter based on a density image indicating the density (color) of the printed matter generated by electrically reading the printed matter is known.

  Further, for example, in Patent Document 1, a density image of the printed matter is generated by electrically reading diffuse reflected light reflected from the printed matter, and the printed matter is read by electrically reading regular reflected light reflected from the printed matter. A gloss image showing the glossiness of the print is generated, the density distribution of the printed matter is inspected based on the density image, and the quality of the printed matter is inspected by inspecting the gloss distribution of the printed matter based on the gloss image. Techniques for doing this are also known.

  In the technique disclosed in Patent Document 1, the illumination device has a configuration in which the illuminance of the regular reflected light reflected from the printed material is not uniform, resulting in uneven illumination in the glossiness image. For this reason, in Patent Document 1, a gloss value image of a reference plate is generated in advance, a correction value for correcting illumination unevenness is calculated, and a gloss value image of a printed matter is generated using the correction value. It is also disclosed to correct the uneven illumination that has occurred.

  Incidentally, the distribution of illumination unevenness that occurs in the glossiness image varies depending on the image clarity of the printed material used to generate the glossiness image. However, in the technique disclosed in Patent Document 1, when correcting the illumination unevenness, Does not consider image clarity. For this reason, the technique disclosed in Patent Document 1 may not be able to accurately correct illumination unevenness generated in the gloss image of the printed matter.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an image processing apparatus, an image processing method, and a program that can accurately correct illumination unevenness generated in a gloss image of a printed matter. To do.

  In order to solve the above-described problems and achieve the object, an image processing apparatus according to an aspect of the present invention is provided on the basis of the reference object, which is generated based on light irradiated from the illumination unit and reflected by the reference object. Based on a reference glossiness image acquisition unit that acquires a reference glossiness image indicating glossiness, a calculation unit that calculates a correction value for correcting illumination unevenness based on the reference glossiness image, and based on the image clarity of the printed matter A correction part for correcting the correction value; and a printed matter glossiness image for obtaining a printed matter glossiness image indicating the glossiness of the printed matter generated based on the light irradiated from the illumination unit and reflected by the printed matter. An image acquisition unit; and a correction unit that corrects the printed gloss image based on the corrected correction value.

  According to the present invention, there is an effect that it is possible to accurately correct illumination unevenness generated in a gloss image of a printed matter.

FIG. 1 is a schematic diagram illustrating an example of a printed matter inspection system according to the first embodiment. FIG. 2 is a schematic diagram illustrating an example of a reading unit according to the first embodiment. FIG. 3 is a block diagram illustrating an example of a hardware configuration of the printing apparatus according to the first embodiment. FIG. 4 is a block diagram illustrating an example of a hardware configuration of the printed matter inspection apparatus according to the first embodiment. FIG. 5 is a block diagram illustrating an example of functional configurations of the printing apparatus and the printed matter inspection apparatus according to the first embodiment. FIG. 6 is an explanatory diagram of the image clarity. FIG. 7 is an explanatory diagram of image clarity. FIG. 8 is an explanatory diagram of image clarity. FIG. 9 is an explanatory diagram of an example of illumination unevenness according to the first embodiment. FIG. 10 is an explanatory diagram of an example of illumination unevenness that occurs in the glossiness image of the first embodiment. FIG. 11 is an explanatory diagram of an example of uneven illumination that occurs in the glossiness image of the first embodiment. FIG. 12 is a diagram illustrating an example of a recording medium selection screen used for generating the printed material according to the first embodiment. FIG. 13 is a diagram illustrating an example of a correction value before correction according to the first embodiment. FIG. 14 is a diagram illustrating an example of a corrected correction value according to the first embodiment. FIG. 15 is a flowchart illustrating an example of a flow of a correction value calculation process performed in the printed matter inspection system according to the first embodiment. FIG. 16 is a flowchart illustrating an example of a flow of a quality inspection process for printed matter performed in the printed matter inspection system according to the first embodiment. FIG. 17 is a block diagram illustrating an example of functional configurations of the printing apparatus and the printed matter inspection apparatus according to the first modification. FIG. 18 is a block diagram illustrating an example of functional configurations of the printing apparatus and the printed matter inspection apparatus according to the second modification. FIG. 19 is a block diagram illustrating an example of functional configurations of the printing apparatus and the printed matter inspection apparatus according to the second embodiment. FIG. 20 is a block diagram illustrating an example of functional configurations of the printing apparatus and the printed matter inspection apparatus according to the third modification. FIG. 21 is a block diagram illustrating an example of functional configurations of the printing apparatus and the printed matter inspection apparatus according to the fourth modification.

  Hereinafter, embodiments of an image processing apparatus, an image processing method, and a program according to the present invention will be described in detail with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a schematic diagram illustrating an example of a printed matter inspection system 1 according to the first embodiment. As illustrated in FIG. 1, the printed matter inspection system 1 includes a printing device 100, a printed matter inspection device 200 (an example of an image processing device), and a stacker 300.

  The printing apparatus 100 includes an operation panel 101, photosensitive drums 103Y, 103M, 103C, and 103K, a transfer belt 105, a secondary transfer roller 107, a paper feeding unit 109, a conveyance roller pair 111, and a fixing roller 113. , And an inversion path 115.

  The operation panel 101 is an operation display unit that performs various operation inputs to the printing apparatus 100 and displays various screens.

  Each of the photosensitive drums 103Y, 103M, 103C, and 103K forms a toner image by performing an image forming process (charging process, exposure process, developing process, transfer process, and cleaning process), and the formed toner image. Is transferred to the transfer belt 105. In the first embodiment, a yellow toner image is formed on the photoconductive drum 103Y, a magenta toner image is formed on the photoconductive drum 103M, a cyan toner image is formed on the photoconductive drum 103C, and the photoconductive drum 103K is formed. However, the present invention is not limited to this.

  The transfer belt 105 conveys the toner image (full color toner image) transferred from the photosensitive drums 103Y, 103M, 103C, and 103K to the secondary transfer position of the secondary transfer roller 107. In the first embodiment, a yellow toner image is first transferred to the transfer belt 105, and then a magenta toner image, a cyan toner image, and a black toner image are sequentially superimposed and transferred. It is not limited.

  The paper feeding unit 109 accommodates a plurality of recording media in an overlapping manner, and feeds the recording media. Examples of the recording medium include, but are not limited to, recording paper. Examples of the recording medium include media capable of recording images, such as coated paper, cardboard, OHP (Overhead Projector) sheet, plastic film, prepreg, and copper foil. Anything is acceptable.

  The transport roller pair 111 transports the recording medium fed by the paper feed unit 109 in the direction of arrow s on the transport path a.

  The secondary transfer roller 107 collectively transfers the full-color toner image conveyed by the transfer belt 105 onto the recording medium conveyed by the conveyance roller pair 111 at the secondary transfer position.

  The fixing roller 113 fixes the full-color toner image on the recording medium by heating and pressing the recording medium on which the full-color toner image is transferred.

  In the case of single-sided printing, the printing apparatus 100 discharges a printed material, which is a recording medium on which a full-color toner image is fixed, to the printed material inspection apparatus 200. On the other hand, in the case of duplex printing, the printing apparatus 100 sends a recording medium on which a full-color toner image is fixed to the reverse path 115.

  The reverse path 115 reverses the front and back surfaces of the recording medium by switching back the sent recording medium and conveys it in the direction of the arrow t. The recording medium conveyed by the reversing path 115 is re-conveyed by the conveying roller pair 111, the full-color toner image is transferred to the surface opposite to the previous one by the secondary transfer roller 107, fixed by the fixing roller 113, and printed. The paper is discharged to the printed product inspection apparatus 200.

  The printed matter inspection apparatus 200 includes a reading unit 201 and an operation panel 203.

  The operation panel 203 is an operation display unit that inputs various operations to the printed material inspection apparatus 200 and displays various screens. Note that the operation panel 203 may be omitted. In this case, the operation panel 101 may also serve as the operation panel 203, or an externally connected PC (Personal Computer) may serve as the operation panel 203.

  The reading unit 201 electrically reads one surface of the printed matter discharged from the printing apparatus 100. FIG. 2 is a schematic diagram illustrating an example of the reading unit 201 according to the first embodiment. As illustrated in FIG. 2, the reading unit 201 includes a gloss illumination device 211 (an example of an illumination unit), a density illumination device 212, and an image sensor 213.

Illuminating unit 211 irradiates illumination light 221a incident at a predetermined incident angle theta ₁ to the printed matter P in the reading region (one line in the main scanning direction). Specular reflected light 221b, the incident direction in print reflection angle illumination light 221a incident at the reading area incident angle theta ₁ is in the reading area of the _{P θ 2 (θ 2 = θ} 1) is reflected on the opposite side reflection The light, ie, the illumination light 221a is reflected light that is specularly reflected in the reading region.

  As the glossy illumination device 211, a device in which a plurality of light emitting elements are arranged in parallel to the reading region of the printed matter P (main scanning direction) can be used. As the light emitting element, for example, a reflective LED (Light Emitting Diode) can be used. In the first embodiment, a case where a blue reflective LED is used as a light emitting element will be described as an example. However, the present invention is not limited to this.

The density illuminating device 212 irradiates the reading region of the printed matter P with illumination light 222a incident at a predetermined incident angle. The predetermined incident angle may be any angle different from the incident angle θ ₁ , for example, 90 degrees. The diffusely reflected light 222b is reflected at a reflection angle (θ _{2 in the} example shown in FIG. ₂ ) that is different from the predetermined incident angle of the illumination light 222a incident on the printed region P at the predetermined incident angle. The reflected light, that is, the reflected light diffusely reflected by the illumination light 222a in the reading area. As the concentration illumination device 212, for example, a diffuse illumination device such as a xenon lamp or an LED array can be used.

  The image sensor 213 receives the regular reflection light 221b and reads the light amount of the regular reflection light 221b, or receives the diffuse reflection light 222b and reads the light amount of the diffuse reflection light 222b. Therefore, the image sensor 213 is disposed at a position where it can receive the regular reflection light 221b and the diffuse reflection light 222b.

  As the image sensor 213, for example, an image sensor in which a plurality of imaging elements are arranged in parallel in the direction parallel to the reading area of the printed matter P (main scanning direction) can be used. As the imaging device, for example, a metal oxide semiconductor device (MOS), a complementary metal oxide semiconductor device (CMOS), a charge coupled device (CCD), and a contact image sensor (CIS) can be used.

  In the first embodiment, the gloss illumination device 211 and the concentration illumination device 212 do not emit light at the same time, and are configured to emit light alternately in accordance with the driving of the image sensor 213. In the first embodiment, every time the printed matter P is conveyed by one line in the sub-scanning direction, the illumination light 221a is irradiated from the glossy illumination device 211, and the image sensor 213 reads the light quantity of the regular reflection light 221b, and the density. The operation of irradiating the illumination light 222a from the illumination device 212 and reading the light amount of the diffuse reflected light 222b by the image sensor 213 is repeated. As a result, the reading unit 201 has a gloss image indicating the glossiness of each pixel of the printed matter P composed of the light amount of the regular reflected light 221b and a density image indicating the density of each pixel of the printed matter P composed of the light amount of the diffusely reflected light 222b. Is read (generated).

  The glossiness is a numerical value representing the degree of specular gloss, and is synonymous with the specular gloss defined in JIS (Japanese Industrial Standards) Z 8741 and ISO (International Organization for Standardization) 2813. That is, the gloss image shows the light distribution of specular reflection light in an arbitrary observation direction as the gloss distribution of the printed matter P, and the density image shows the light amount distribution of diffuse reflection light in an arbitrary observation direction as the density distribution of the print P. Indicates. Note that details of reading the glossiness image and the density image are disclosed in, for example, Patent Document 1.

  In the first embodiment, it is assumed that the image sensor 213 has at least three primary color channels of R, G, and B. However, the present invention is not limited to this. For example, the image sensor 213 may have channels other than the three primary colors such as infrared and ultraviolet by a color filter or the like. In the first embodiment, the image sensor 213 reads all the RGB channels (three channels) when reading either the glossiness image or the density image. However, the present invention is not limited to this. It is not a thing.

  For example, for glossiness images, the glossiness distribution can be expressed by information obtained by reading for one channel, so that any one channel may be used for reading glossiness images. . However, when the printed material is a catalog or the like, the quality of the paper may differ depending on the page, varnishing or processing may be performed to give gloss, or partial processing may be performed only on the portion where gloss is desired. In this way, when various glosses are mixed in the printed material, the measurement range is not sufficient for one channel, and the distribution of glossiness cannot be accurately represented by the information obtained by reading one channel. A glossiness image may be read.

  Returning to FIG. 1, the printed matter inspection apparatus 200 discharges the printed matter that has been read to the stacker 300. The printed matter inspection apparatus 200 may further include a reading unit that optically reads the other surface of the printed matter. In this case, the reading unit that optically reads the other surface of the printed material may have the same configuration as the reading unit 201.

  The stacker 300 includes a tray 311. The stacker 300 stacks the printed materials discharged by the printed material inspection apparatus 200 on the tray 311.

  FIG. 3 is a block diagram illustrating an example of a hardware configuration of the printing apparatus 100 according to the first embodiment. As shown in FIG. 3, the printing apparatus 100 has a configuration in which a controller 810 and an engine unit (Engine) 860 are connected by a PCI bus. The controller 810 is a controller that controls the entire control of the printing apparatus 100, drawing, communication, and input from the operation display unit 820. The engine unit 860 is an engine that can be connected to the PCI bus, and is, for example, a print engine such as a plotter. The engine unit 860 includes an image processing part such as error diffusion and gamma conversion in addition to the engine part.

  The controller 810 includes a CPU (Central Processing Unit) 811, a North Bridge (NB) 813, a system memory (MEM-P) 812, a South Bridge (SB) 814, a local memory (MEM-C) 817, and an ASIC. (Application Specific Integrated Circuit) 816 and a hard disk drive (HDD) 818, and the North Bridge (NB) 813 and the ASIC 816 are connected by an AGP (Accelerated Graphics Port) bus 815. The MEM-P 812 further includes a ROM 812a and a RAM 812b.

  The CPU 811 performs overall control of the printing apparatus 100, has a chip set including the NB 813, the MEM-P 812, and the SB 814, and is connected to other devices via this chip set.

  The NB 813 is a bridge for connecting the CPU 811 to the MEM-P 812, SB 814, and the AGP bus 815, and includes a memory controller that controls reading and writing of the MEM-P 812, a PCI master, and an AGP target.

  The MEM-P 812 is a system memory used as a memory for storing programs and data, a memory for developing programs and data, a memory for drawing printers, and the like, and includes a ROM 812a and a RAM 812b. The ROM 812a is a read-only memory used as a program / data storage memory, and the RAM 812b is a writable / readable memory used as a program / data development memory, a printer drawing memory, or the like.

  The SB 814 is a bridge for connecting the NB 813 to a PCI device and peripheral devices. The SB 814 is connected to the NB 813 via a PCI bus, and a network interface (I / F) unit and the like are also connected to the PCI bus.

  The ASIC 816 is an IC (Integrated Circuit) for image processing applications having hardware elements for image processing, and has a role of a bridge for connecting the AGP bus 815, the PCI bus, the HDD 818, and the MEM-C 817. The ASIC 816 includes a PCI target and an AGP master, an arbiter (ARB) that forms the core of the ASIC 816, a memory controller that controls the MEM-C 817, and a plurality of DMACs (Direct Memory) that rotate image data using hardware logic. Access Controller) and a PCI unit that performs data transfer between the engine unit 860 via the PCI bus. The ASIC 816 is connected to a USB 840 and an IEEE 1394 (the Institute of Electrical and Electronics Engineers 1394) interface (I / F) 850 via a PCI bus. The operation display unit 820 is directly connected to the ASIC 816.

  The MEM-C 817 is a local memory used as a copy image buffer and a code buffer, and the HDD 818 is a storage for storing image data, programs, font data, and forms.

  The AGP bus 815 is a bus interface for a graphics accelerator card proposed for speeding up graphics processing. The AGP bus 815 speeds up the graphics accelerator card by directly accessing the MEM-P812 with high throughput. It is.

  FIG. 4 is a block diagram illustrating an example of a hardware configuration of the printed matter inspection apparatus 200 according to the first embodiment. As shown in FIG. 4, the printed matter inspection apparatus 200 has a configuration in which a controller 910 and an engine unit (Engine) 960 are connected by a PCI bus. The controller 910 is a controller that controls the overall control, drawing, communication, and input from the operation display unit 920 of the printed matter inspection apparatus 200. The engine unit 960 is an engine that can be connected to the PCI bus, and is, for example, a scanner engine such as a scanner. The engine unit 960 includes an image processing part such as error diffusion and gamma conversion in addition to the engine part.

  The controller 910 includes a CPU 911, a north bridge (NB) 913, a system memory (MEM-P) 912, a south bridge (SB) 914, a local memory (MEM-C) 917, an ASIC 916, and a hard disk drive (HDD). 918, and the north bridge (NB) 913 and the ASIC 916 are connected by the AGP bus 915. The MEM-P 912 further includes a ROM 912a and a RAM 912b.

  The CPU 911 performs overall control of the printed matter inspection apparatus 200, has a chip set including the NB 913, the MEM-P 912, and the SB 914, and is connected to other devices via the chip set.

  The NB 913 is a bridge for connecting the CPU 911 to the MEM-P 912, SB 914, and the AGP bus 915, and includes a memory controller that controls reading and writing to the MEM-P 912, a PCI master, and an AGP target.

  The MEM-P 912 is a system memory used as a memory for storing programs and data, a memory for developing programs and data, a memory for drawing printers, and the like, and includes a ROM 912a and a RAM 912b. The ROM 912a is a read-only memory used as a memory for storing programs and data, and the RAM 912b is a writable and readable memory used as a program / data development memory, a printer drawing memory, and the like.

  The SB 914 is a bridge for connecting the NB 913 to a PCI device and a peripheral device. The SB 914 is connected to the NB 913 via a PCI bus, and a network interface (I / F) unit and the like are also connected to the PCI bus.

  The ASIC 916 is an IC for image processing that includes hardware elements for image processing, and has a role of a bridge that connects the AGP bus 915, the PCI bus, the HDD 918, and the MEM-C 917. The ASIC 916 includes a PCI target and an AGP master, an arbiter (ARB) that forms the core of the ASIC 916, a memory controller that controls the MEM-C 917, a plurality of DMACs that rotate image data using hardware logic, and the like. And a PCI unit that performs data transfer with the unit 960 via the PCI bus. The ASIC 916 is connected to a USB 940 and an IEEE 1394 interface (I / F) 950 via a PCI bus. The operation display unit 920 is directly connected to the ASIC 916.

  The MEM-C 917 is a local memory used as a copy image buffer and a code buffer, and the HDD 918 is a storage for storing image data, programs, font data, and forms.

  The AGP bus 915 is a bus interface for a graphics accelerator card proposed for speeding up graphics processing. The AGP bus 915 speeds up the graphics accelerator card by directly accessing the MEM-P 912 with high throughput. It is.

  FIG. 5 is a block diagram illustrating an example of functional configurations of the printing apparatus 100 and the printed matter inspection apparatus 200 according to the first embodiment. As illustrated in FIG. 5, the printing apparatus 100 includes a RIP (Raster Image Processor) unit 121, a print control unit 123, and a printing unit 125. The printed material inspection apparatus 200 includes a reading unit 251, a reference gloss image acquisition unit 253, a calculation unit 255, a storage unit 257, a reception unit 259, a display control unit 261, a correction unit 263, and a printed material gloss image. An acquisition unit 265, a density image acquisition unit 267, a difference image generation unit 269, a correction unit 271 and an inspection unit 273 are provided.

  In the first embodiment, the case where the printing apparatus 100 includes the RIP unit 121 will be described as an example. However, the present invention is not limited to this, and an apparatus different from the printing apparatus 100 such as DFE (Digital Front End) is used. You may make it provide.

  In the first embodiment, it is assumed that the printing apparatus 100 and the printed matter inspection apparatus 200 are connected by a local interface such as USB (Universal Serial Bus) or PCIe (Peripheral Component Interconnect Express). The connection form between the printing apparatus 100 and the printed matter inspection apparatus 200 is not limited to this.

  The RIP unit 121 and the print control unit 123 can be realized by the CPU 811 and the system memory 812, for example. The printing unit 125 is realized by, for example, the photosensitive drums 103Y, 103M, 103C, and 103K, the transfer belt 105, the secondary transfer roller 107, and the fixing roller 113, but is not limited thereto. As described above, in the first embodiment, an image is printed by an electrophotographic method, but the present invention is not limited to this, and an image may be printed by an inkjet method.

  The reading unit 251 includes the reading unit 201 and can be realized by the engine unit 960, for example. The reference gloss image acquisition unit 253, the calculation unit 255, the reception unit 259, the display control unit 261, the correction unit 263, the printed material gloss image acquisition unit 265, and the density image acquisition unit 267 are, for example, by the CPU 911 and the system memory 912. realizable. The difference image generation unit 269, the correction unit 271 and the inspection unit 273 may be realized by, for example, the CPU 911 and the system memory 912, or may be realized by the ASIC 916 or the like, or may be realized by using these in combination. Also good. Note that the difference image generation unit 269, the correction unit 271, and the inspection unit 273 may be realized by a GPU (Graphics Processing Unit) instead of the CPU 911. The storage unit 257 can be realized by the HDD 918 or the like, for example.

  1 is realized by the operation display unit 820, and the operation panel 203 shown in FIG. 1 is realized by the operation display unit 920.

  In the following, regarding the operations of the printing apparatus 100 and the printed matter inspection apparatus 200, the correction value calculation operation for correcting illumination unevenness will be described first, and then the inspection operation for inspecting the quality of the printed matter will be described.

  First, the correction value calculation operation will be described.

  The reading unit 201 reads the reference object and generates a reference gloss image indicating the glossiness of the reference object. Specifically, the gloss illumination device 211 that constitutes the reading unit 201 irradiates the reference object with illumination light 221a, and the image sensor 213 that constitutes the reading unit 201 emits specularly reflected light 221b reflected by the reference object. By reading (based on), a reference glossiness image is generated. In the first embodiment, the reference glossiness image is assumed to be RGB image data, but is not limited to this.

  In the first embodiment, the reference object is an object having a higher image clarity than the printed matter to be inspected (specifically, a recording medium used for generating the printed matter) (for example, a record having a higher image clarity than the printed matter to be inspected). The reason for this will be described later. Note that the image clarity is synonymous with the image clarity defined by, for example, JIS Z 8741 and ISO 2813. Specifically, how clearly the image of an object reflected on the surface of the film looks clear and undistorted. The degree is expressed as a numerical value (percentage).

  In other words, the higher the image clarity, the clearer the image of the reflected object, and the lower the image clarity, the more the image of the reflected object will be corrupted and blurred. For example, when the recording medium on which the character “A” shown in FIG. 6 is printed has high image clarity, the reflected object image is clear as shown in FIG. On the other hand, when the recording medium on which the character “A” shown in FIG. 6 is printed has low image clarity, the reflected object image is blurred as shown in FIG.

  In the case of reading a reference object, the reading unit 201 may generate at least a reference glossiness image and may not generate a density image. That is, the concentration illumination device 212 constituting the reading unit 201 may not irradiate the reference object with the illumination light 222a.

  The reference glossiness image acquisition unit 253 acquires the reference glossiness image generated by the reading unit 201.

  The calculation unit 255 calculates a correction value for correcting illumination unevenness based on the reference glossiness image acquired by the reference glossiness image acquisition unit 253, and stores the correction value in the storage unit 257.

  Here, illumination unevenness that occurs in the glossiness image generated by the reading unit 201 will be described. FIG. 9 is an explanatory diagram of an example of illumination unevenness according to the first embodiment. As shown in FIG. 9, since the glossy illumination device 211 has a configuration in which a plurality of reflective LEDs are arranged in parallel, the illumination between the reflective LEDs becomes weak. For this reason, the illuminance of the illumination light 221a emitted from the gloss illumination device 211 and the regular reflection light 221b of the illumination light 221a has a distribution like the illuminance distribution 311 and the illuminance is not uniform. As a result, illumination unevenness occurs in the glossiness image 312 generated when the reading unit 201 (image sensor 213) reads the regular reflection light 221b as shown in FIG.

  Therefore, the calculation unit 255 calculates a correction value for correcting the illumination unevenness as described above using the reference glossiness image.

  For example, the calculation unit 255 calculates the correction value using Equation (1).

  Here, x indicates the x coordinate of the reference glossiness image, and y indicates the y coordinate of the reference glossiness image. The x-axis direction is the main scanning direction, and the y-axis direction is the sub-scanning direction. S (x, y) indicates the pixel value of the pixel (x, y). h indicates the number of pixels in the sub-scanning direction (maximum value of the y coordinate). K (x) represents a correction value at the x coordinate.

  That is, in Equation (1), an average value of pixel values in the y-axis direction (sub-scanning direction) is calculated as a correction value for each x coordinate.

  Further, for example, the calculation unit 255 may calculate the correction value by removing the pixel value that has become an abnormal value due to the influence of noise or the like using Expression (2).

  Here, μ represents an average value of pixel values of the reference glossiness image, and σ represents a standard deviation of pixel values of the reference glossiness image. In Equation (2), as described above, pixel values that satisfy μ−3σ <S (x, y) <μ + 3σ are calculated in order to calculate correction values by removing pixel values that have become abnormal values due to noise or the like. The correction value (average value) is calculated using.

  Further, for example, the calculation unit 255 may calculate the correction value by using the formula (3) and reflecting the weight according to the illumination unevenness.

  Here, D (x) is a weight obtained based on the illuminance distribution 311. Specifically, among the illuminances indicated by the illuminance distribution 311, the weight for the illuminance at the position corresponding to the x coordinate of the reference glossiness image. It is.

  Here, the reason why the above-described image clarity of the reference object is made higher than that of the printed material to be inspected (specifically, the recording medium used for generating the printed material) will be described. FIG. 10 is a diagram illustrating a gloss image 321 of an object with low image clarity (for example, plain paper) and a gloss image 322 of an object with high image clarity (for example, coated paper). A graph 341 in which an average value of pixel values in the sub-scanning direction of the glossiness image 321 is plotted for each pixel position in the main scanning direction, and an average value of pixel values in the sub-scanning direction of the glossiness image 322 are calculated in the main scanning direction. It is a figure which shows the graph 342 plotted for every pixel position. It should be noted that the conditions for generating the glossiness image 321 and the glossiness image 322 (the illumination device to be used and the state of the paper) are the same.

  As apparent from FIGS. 10 and 11, the unevenness of illumination is more clearly reflected in the glossiness image 322 than in the glossiness image 321, but this was used to generate the glossiness image 322. This is because the object has higher image clarity than the glossiness image 321. As described above, the glossiness image of an object having high image clarity can clearly reflect not only the image of the object but also the illumination unevenness of the illumination device used for generating the glossiness image.

  In the first embodiment, as will be described in detail later, illumination unevenness generated in the gloss image of the printed material to be inspected is corrected based on the correction value calculated using the reference gloss image. At this time, if the image clarity of the reference object used for generating the reference gloss image is lower than the image clarity of the printed matter to be inspected, it is based on the correction value calculated from the reference gloss image with low illumination unevenness. The illumination unevenness of the gloss image of the printed matter to be inspected in which the illumination unevenness state is clearly reflected is corrected, and the illumination unevenness cannot be corrected with high accuracy.

  For this reason, in the first embodiment, an object with higher image clarity than the printed material to be inspected is used as a reference object, and illumination unevenness is based on a correction value calculated from a reference glossiness image in which the state of illumination unevenness is clearly reflected. By correcting the illumination unevenness of the gloss image of the printed matter to be inspected whose sharpness in the state is lower than that of the reference gloss image, the illumination unevenness of the gloss image of the printed matter to be inspected can be accurately corrected.

  When the correction value is stored in the storage unit 257, the display control unit 261 displays on the operation panel 203 an input screen for inputting the image clarity of the reference object for which the correction value is obtained. For example, the display control unit 261 displays an input screen for inputting the identification information for identifying the reference object for which the correction value stored in the storage unit 257 is obtained and the image clarity information indicating the image clarity of the reference object. To display. Note that the image clarity indicated by the image clarity information is represented by, for example, a value in the range of 0% to 100%, and the higher the value (percentage), the higher the image clarity.

  The accepting unit 259 accepts the input of the identification information and the image clarity information of the reference object for which the correction value has been obtained by an operation input from the operation panel 203 by the user, and stores it in the storage unit 257 in association with the correction value. It should be noted that since the mapping property of the reference object is known to the user, the user can input the mapping property information of the reference object.

  Next, an inspection operation for inspecting the quality of the printed material will be described.

  First, the reception unit 259 receives input of image clarity information indicating the image clarity of a printed material to be inspected (specifically, a recording medium used for generating the printed material).

  For example, the display control unit 261 displays on the operation panel 203 a selection screen for allowing the user to select a recording medium used for generating printed matter as shown in FIG. 12, and the reception unit 259 displays the selection screen from the operation panel 203 by the user. By accepting an input for selecting a recording medium to be used for generating a printed material by an operation input, an input of image clarity information of the recording medium is accepted. In this example, the storage unit 257 stores the mapping information of the recording medium in association with the identification information of the recording medium to be selected, and the reception unit 259 stores the information on the storage medium selected by the user. By obtaining the image clarity information associated with the identification information from the storage unit 257, the image clarity information of the storage medium is received. In the example illustrated in FIG. 12, among the PaperA to PaperD displayed in the selection candidate field 332, PaperA is selected by the user and displayed in the selection field 331, so the accepting unit 259 displays the mapping information of PaperA. Accept.

  The correcting unit 263 obtains a correction value (calculated by the calculating unit 255 from the reference glossiness image) stored in the storage unit 257 based on the image clarity of the printed material to be inspected (specifically, the recording medium used for generating the printed material). Corrected correction value). Specifically, the correction unit 263 corrects the correction value stored in the storage unit 257 based on the mapping property indicated by the mapping property information of the printed material to be inspected received by the receiving unit 259. Specifically, the correcting unit 263 acquires the reference object correction value and the mapping information stored in the storage unit 257, and the acquired mapping property information and the mapping of the printed matter to be inspected received by the receiving unit 259. The correction value of the acquired reference object is corrected using the sex information.

  For example, the correction unit 263 corrects the correction value using Equation (4).

Here, F (i) represents a filter function. Examples of the filter function F (i) include a smoothing filter shown in Formula (5) (provided that it is a moving average) and a Gaussian filter shown in Formula (6).

  F indicates a filter coefficient, n indicates a filter size, and K ′ (x) indicates a corrected correction value. The filter size n preferably increases as the difference between the image clarity of the reference object and the image print quality of the inspection object increases. For example, n = A × (image clarity of the reference object−print quality of the inspection object) Image clarity). A indicates an attenuation coefficient.

  Thereby, the correction value is corrected to a value suitable for correcting the state of uneven illumination reflected on the glossiness image of the printed material to be inspected, which is assumed from the image clarity of the printed material to be inspected (dullness). ). For example, when the correction value is represented by a value like the graph shown in FIG. 13, the correction value is corrected (blunted) to the value like the graph shown in FIG. 14 by this correction.

  The RIP unit 121 receives print data from an external device such as a host device, performs RIP processing on the received print data, and generates a RIP image. In the first embodiment, the print data includes job information described in a page description language (PDL) such as PostScript (registered trademark), image data in a TIFF (Tagged Image File Format) format, and the like. However, the present invention is not limited to this. In the first embodiment, the RIP image is CMYK RIP image data. However, the present invention is not limited to this.

  The print control unit 123 transmits the RIP image generated by the RIP unit 121 to the printing unit 125 and transmits the RIP image to the printed matter inspection apparatus 200.

  The printing unit 125 executes a printing process such as an image forming process, prints a print image based on the RIP image on a recording medium, and generates a printed material.

  The reading unit 201 reads the printed material to be inspected printed (generated) by the printing unit 125, generates a density image indicating the density of the printed material, and generates a printed material gloss image indicating the glossiness of the printed material. Generate. Specifically, the density illumination device 212 constituting the reading unit 201 irradiates the printed matter to be inspected with illumination light 222a, and the image sensor 213 constituting the reading unit 201 is reflected by the printed matter to be inspected. By reading (based on) the reflected light 222b, a density image is generated. The generation of the printed gloss image is the same as the generation of the reference gloss image except that the reference object is a printed material to be inspected. In the first embodiment, the density image and the printed material glossiness image are RGB image data, but are not limited thereto.

  The printed material gloss image acquisition unit 265 acquires the printed material gloss image generated by the reading unit 201.

  The correcting unit 271 corrects the printed material glossiness image acquired by the printed material glossiness image acquiring unit 265 based on the correction value corrected by the correcting unit 263. For example, the correction unit 271 corrects the printed material glossiness image using Expression (7).

  Here, A represents a constant, and the higher the gloss of the reference object is, the higher the value is, and the lower the gloss of the reference object is, the lower the value is. For example, A = 250, assuming that one pixel of the printed product glossiness image is 8 bits and the glossiness of the reference product is the upper limit of photographing. S ′ (x, y) indicates a pixel value after correction of the pixel (x, y).

  Thereby, illumination unevenness on the printed product glossiness image is corrected.

  The density image acquisition unit 267 acquires the density image generated by the reading unit 201.

  The difference image generation unit 269 acquires a RIP image from the printing apparatus 100 and generates a reference image (master image) based on the acquired RIP image. Specifically, the difference image generation unit 269 acquires RIP images of C, M, Y, and K from the printing apparatus 100 (print control unit 123), and acquires the acquired RIPs of C, M, Y, and K, respectively. The image is subjected to various image processing such as multi-value conversion processing, smoothing processing, resolution conversion processing, and color conversion processing to generate a reference image. In the first embodiment, the reference image is RGB image data, but is not limited to this.

  Then, the difference image generation unit 269 generates a difference image indicating a difference between the generated reference image and the density image acquired by the density image acquisition unit 267. Specifically, the difference image generation unit 269 compares the reference image and the density image in units of pixels, calculates the difference values of the pixel values of each RGB color for each pixel, and includes the difference values of the pixel values for each pixel. A difference image is generated.

  The inspection unit 273 inspects the printed material based on the printed material gloss image corrected by the correction unit 271. For example, the inspection unit 273 inspects the gloss defect of the printed material based on the magnitude relationship between the pixel value of each pixel constituting the printed material glossiness image corrected by the correcting unit 271 and the threshold value for the glossiness inspection. In addition, about the inspection method of the printed matter using a printed matter glossiness image, since the method described in patent document 1 should just be employ | adopted for example, detailed description is abbreviate | omitted.

  The inspection unit 273 inspects the printed matter based on the difference image generated by the difference image generation unit 269. For example, the inspection unit 273 prints the printed matter generated by the printing apparatus 100 based on the magnitude relationship between the difference value of each pixel constituting the difference image generated by the difference image generation unit 269 and the threshold value for density degree inspection. Inspect for density defects. For example, a density defect is caused at a location (pixel group) having a large difference value or a location (pixel group) having a large difference area.

  The inspection unit 273 stores the inspection result such as the position and type of the glossy defect and the density defect, the density image, the glossiness image, and the difference image in association with each other in the HDD 918 or transmits (feedback) to the printing apparatus 100. To do. Note that the display control unit 261 may display the inspection result of the inspection unit 273.

  FIG. 15 is a flowchart illustrating an example of a flow of a correction value calculation process performed in the printed matter inspection system 1 according to the first embodiment.

  First, the reference glossiness image acquisition unit 253 acquires the reference glossiness image generated by the reading unit 201 (step S101).

  Subsequently, the calculation unit 255 calculates a correction value for correcting illumination unevenness based on the reference glossiness image acquired by the reference glossiness image acquisition unit 253, and stores the correction value in the storage unit 257 (step S103). .

  The accepting unit 259 accepts the input of the identification information and the image clarity information of the reference object for which the correction value has been obtained by the operation input from the operation panel 203 by the user, and stores it in the storage unit 257 in association with the correction value. To do.

  FIG. 16 is a flowchart illustrating an example of a flow of a quality inspection process for a printed material performed by the printed material inspection system 1 according to the first embodiment. However, the processing order is not limited to this.

  First, the accepting unit 259 accepts input of image clarity information indicating the image clarity of a printed matter to be inspected (specifically, a recording medium used for generating the printed matter) (step S201).

  Subsequently, the correction unit 263 acquires the reference object correction value and the image clarity information stored in the storage unit 257, and the image clarity information acquired and the image clarity of the printed material to be inspected received by the reception unit 259. Using the information, the correction value of the acquired reference object is corrected (step S203).

Subsequently, the density image acquisition unit 267 acquires the density image generated by the reading unit 201 (step S205).

  Subsequently, the printed matter glossiness image acquisition unit 265 acquires the printed matter glossiness image generated by the reading unit 201 (step S207).

  Subsequently, the difference image generation unit 269 acquires a reference image by acquiring a RIP image from the printing apparatus 100 and generating a reference image (master image) based on the acquired RIP image (step S209).

  Subsequently, the difference image generation unit 269 generates a difference image indicating a difference between the acquired reference image and the density image acquired by the density image acquisition unit 267 (step S211).

  Subsequently, the correcting unit 271 corrects the printed material gloss image acquired by the printed material gloss image acquiring unit 265 based on the correction value corrected by the correcting unit 263 (step S213).

  Subsequently, the inspection unit 273 inspects the printed material based on the difference image generated by the difference image generation unit 269 and the printed material glossiness image corrected by the correction unit 271 (step S215).

  As described above, according to the first embodiment, the correction value for correcting the illumination unevenness generated from the reference material is corrected in consideration of the image clarity of the printed material, and the gloss value of the printed material is corrected using the corrected correction value. Since the illumination unevenness generated in the image is corrected, it is possible to accurately correct the illumination unevenness generated in the gloss image of the printed matter. For this reason, if the gloss defect of the printed matter is inspected using the gloss image of the printed matter, the gloss defect of the printed matter can be detected with high accuracy.

(Modification 1)
In the first modification, an example in which the image clarity information of the reference object and the image clarity information of the printed matter to be inspected are automatically input will be described. In the following, differences from the first embodiment will be mainly described, and components having the same functions as those in the first embodiment will be given the same names and symbols as those in the first embodiment, and description thereof will be given. Is omitted.

  FIG. 17 is a block diagram illustrating an example of functional configurations of the printing apparatus 100 and the printed matter inspection apparatus 1200 according to the first modification. As illustrated in FIG. 17, the printed matter inspection apparatus 1200 according to the first modification is different from the first embodiment in a detection unit 1275 and a correction unit 1263.

  The detecting unit 1275 detects the image clarity from the reference object or detects the image clarity from the printed material to be inspected. Examples of the detection unit 1275 include a dedicated detection device for detecting the image clarity of an object defined by JIS Z 8741 or ISO 2813.

  The correction unit 1263 corrects the correction value based on the image clarity of the printed material to be inspected detected by the detection unit 1275. Specifically, in the correction value calculation operation, the correction unit 1263 stores the mapping information of the reference object in association with the correction value when the detection unit 1275 detects the mapping of the reference object. Store in the unit 257. In the quality inspection operation of the printed material, the correction unit 1263 detects the reference value correction value and the image clarity information stored in the storage unit 257 when the detection unit 1275 detects the mapping property of the printed material to be inspected. And the correction value of the acquired reference object is corrected using the acquired image clarity information and the image clarity information of the printed matter to be inspected detected by the detection unit 1275.

  As described above, Modification 1 also has the same effects as those of the first embodiment.

(Modification 2)
In the second modification, an example in which a gloss defect of a printed material is visually observed by an inspector will be described. In the following, differences from the first embodiment will be mainly described, and components having the same functions as those in the first embodiment will be given the same names and symbols as those in the first embodiment, and description thereof will be given. Is omitted.

  FIG. 18 is a block diagram illustrating an example of functional configurations of the printing apparatus 100 and the printed matter inspection apparatus 2200 according to the second modification. As illustrated in FIG. 18, the printed matter inspection apparatus 2200 according to the second modification is different from the first embodiment in an inspection unit 2273 and a display control unit 2261.

  The display control unit 2261 displays an image based on the printed material glossiness image corrected by the correction unit 271 on the operation panel 203. Thereby, the inspector can visually confirm the gloss defect of the printed matter by confirming the image displayed on the operation panel 203. The image based on the printed material glossiness image may be the printed material glossiness image itself or an image obtained by performing some image processing on the printed material glossiness image.

  The inspection unit 2273 acquires the inspection result by the inspector's visual inspection for the inspection of the gloss defect of the printed material (for example, received from the reception unit 259), and the inspection of the density defect of the printed material is the same as in the first embodiment. Just do it.

  As described above, the second modification also has the same effect as that of the first embodiment.

(Second Embodiment)
In the second embodiment, an example will be described in which correction values are obtained for a plurality of reference objects, and the printed product glossiness image is corrected using the correction values of the reference object whose image clarity is closest to the printed material to be inspected. In the following, differences from the first embodiment will be mainly described, and components having the same functions as those in the first embodiment will be given the same names and symbols as those in the first embodiment, and description thereof will be given. Is omitted.

  FIG. 19 is a block diagram illustrating an example of functional configurations of the printing apparatus 100 and the printed matter inspection apparatus 3200 according to the second embodiment. As illustrated in FIG. 19, a printed matter inspection apparatus 3200 according to the second embodiment is different from the first embodiment in a correction unit 3271 and a selection unit 3277.

  However, in the second embodiment, the correction value calculation operation is performed for each of a plurality of reference objects. That is, the reference gloss image acquisition unit 253 acquires a reference gloss image of the reference object for each reference object, and the calculation unit 255 performs illumination for each reference gloss image based on the reference gloss image. A correction value for correcting unevenness is calculated, and the receiving unit 259 receives, for each reference object, input of identification information and image clarity information of the reference object, and associates with the correction value of the reference object to store the storage unit Store in 257.

  The selection unit 3277 selects a correction value corresponding to the image clarity of the printed material from among the plurality of correction values calculated by the calculation unit 255. Specifically, the selection unit 3277 uses the mapping property information of the printed matter to be inspected received by the receiving unit 259, and obtains the mapping property closest to the mapping property indicated by the mapping information from the storage unit 257. The correction value of the reference object associated with the image clarity information shown is acquired.

  The correction unit 3271 corrects the printed product glossiness image acquired by the printed product glossiness image acquisition unit 265 based on the correction value selected by the selection unit 3277.

  As described above, according to the second embodiment, it is assumed from the correction value for correcting the illumination unevenness generated from the reference material having the mapping property closest to the mapping property of the printed material, that is, the imaging property of the printed material to be inspected. The illumination unevenness generated in the gloss image of the printed material is corrected using a correction value suitable for correcting the state of illumination unevenness reflected in the gloss image of the printed material to be inspected. For this reason, the illumination unevenness which arose in the glossiness image of printed matter can be correct | amended accurately. For this reason, if the gloss defect of the printed matter is inspected using the gloss image of the printed matter, the gloss defect of the printed matter can be detected with high accuracy.

(Modification 3)
In the third modification, an example in which the image clarity information of the reference object and the image clarity information of the printed matter to be inspected are automatically input will be described. In the following description, differences from the second embodiment will be mainly described, and components having the same functions as those of the second embodiment will be given the same names and symbols as those of the first embodiment, and the description thereof will be made. Is omitted.

  FIG. 20 is a block diagram illustrating an example of functional configurations of the printing apparatus 100 and the printed matter inspection apparatus 4200 according to the third modification. As illustrated in FIG. 20, a printed matter inspection apparatus 4200 according to Modification 3 is different from the second embodiment in a detection unit 1275 and a selection unit 4277.

  The detecting unit 1275 detects the image clarity from the reference object or detects the image clarity from the printed material to be inspected. Examples of the detection unit 1275 include a dedicated detection device for detecting the image clarity of an object defined by JIS Z 8741 or ISO 2813.

  The selection unit 4277 selects a correction value based on the image clarity of the printed material to be inspected detected by the detection unit 1275. Specifically, in the correction value calculation operation, when the detection unit 1275 detects the mapping property of the reference object, the selection unit 4277 stores the mapping property information of the reference object in association with the correction value. Store in the unit 257. Then, during the quality inspection operation of the printed material, when the detection unit 1275 detects the mapping property of the printed material to be inspected, the selection unit 4277 shows the mapping property closest to the mapping property from the storage unit 257. The correction value of the reference object associated with the image clarity information is acquired.

  As described above, the third modification also has the same effect as that of the second embodiment.

(Modification 4)
In Modification 4, an example in which a gloss defect of a printed material is visually observed by an inspector will be described. In the following, differences from the second embodiment will be mainly described, and components having the same functions as those of the second embodiment will be given the same names and symbols as those of the second embodiment, and the description thereof will be made. Is omitted.

  FIG. 21 is a block diagram illustrating an example of functional configurations of the printing apparatus 100 and the printed matter inspection apparatus 5200 according to the fourth modification. As shown in FIG. 21, the printed matter inspection apparatus 5200 of Modification 4 is different from the second embodiment in the inspection unit 5273 and the display control unit 5261.

  The display control unit 5261 displays an image based on the printed material glossiness image corrected by the correction unit 3271 on the operation panel 203. Thereby, the inspector can visually confirm the gloss defect of the printed matter by confirming the image displayed on the operation panel 203. The image based on the printed material glossiness image may be the printed material glossiness image itself or an image obtained by performing some image processing on the printed material glossiness image.

  The inspection unit 5273 acquires the inspection result of the inspector's visual inspection for the inspection of the gloss defect of the printed matter (for example, received from the reception unit 259), and the inspection of the density defect of the printed matter is the same as in the second embodiment. Just do it.

  As described above, the fourth modification also has the same effect as that of the second embodiment.

(Modification 5)
In each of the above embodiments and modifications, the case where the printed matter inspection apparatus is realized by a dedicated apparatus has been described as an example. However, a combination of an image reading apparatus that realizes the function of the reading unit 251 and a general-purpose computer such as a PC. Thus, a printed matter inspection apparatus may be realized.

(program)
The program executed by the printed matter inspection apparatus according to each of the above embodiments and modifications is a file in an installable or executable format, such as a CD-ROM, CD-R, memory card, DVD (Digital Versatile Disk), flexible The program is stored in a computer-readable storage medium such as a disk (FD).

  Further, the program executed by the printed matter inspection apparatus of each of the embodiments and the modifications may be provided by being stored on a computer connected to a network such as the Internet and downloaded via the network. Further, the program executed by the printed matter inspection apparatus according to each of the embodiments and the modifications may be provided or distributed via a network such as the Internet. Further, a program executed by the printed matter inspection apparatus of each of the above embodiments and modifications may be provided by being incorporated in advance in a ROM or the like.

  The program executed by the printed matter inspection apparatus according to each of the embodiments and the modifications has a module configuration for realizing the above-described units on a computer. As actual hardware, for example, the CPU reads out a program from the ROM to the RAM and executes the program, so that each functional unit is realized on the computer.

  In addition, the said embodiment and each modification are shown as an example, and are not intending limiting the range of invention. The above-described novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 Printed product inspection system 100 Printing apparatus 101 Operation panel 103Y, 103M, 103C, 103K Photosensitive drum 105 Transfer belt 107 Secondary transfer roller 109 Paper feed part 111 Conveying roller pair 113 Fixing roller 115 Reverse path 121 RIP part 123 Print control part 125 Print unit 200, 1200, 2200, 3200, 4200, 5200 Printed product inspection device 201 Reading unit 203 Operation panel 211 Glossy illumination device 212 Density illumination device 213 Image sensor 251 Reading unit 253 Reference glossiness image acquisition unit 255 Calculation unit 257 Storage Unit 259 Reception unit 261, 2261, 5261 Display control unit 263, 1263 Correction unit 265 Print glossiness image acquisition unit 267 Density image acquisition unit 269 Difference image generation unit 271, 3271 Correction unit 273, 2273, 5273 Inspection unit 1275 Detection unit 3277, 4277 Selection unit

Japanese Patent No. 5585228

Claims (14)

A reference gloss image acquisition unit that acquires a reference gloss image indicating the glossiness of the reference object, generated based on the light irradiated from the illumination unit and reflected by the reference object;
A calculation unit that calculates a correction value for correcting illumination unevenness based on the reference gloss image;
A correction unit for correcting the correction value based on the image clarity of the printed matter;
A printed product gloss image acquisition unit that acquires a printed product gloss image indicating the gloss of the printed product, generated based on the light irradiated from the illumination unit and reflected by the printed product;
A correcting unit that corrects the printed gloss image based on the corrected correction value;
An image processing apparatus comprising: A reception unit for receiving input of image clarity information indicating the image clarity;
The image processing apparatus according to claim 1, wherein the correction unit corrects the correction value based on the image clarity indicated by the received image clarity information. A detection unit for detecting the image clarity from the printed matter;
The image processing apparatus according to claim 1, wherein the correction unit corrects the correction value based on the detected image clarity.   The image processing apparatus according to claim 1, further comprising an inspection unit that inspects the printed matter based on the corrected printed matter glossiness image.   The image processing apparatus according to claim 1, further comprising: a display control unit that displays an image based on the corrected printed glossiness image. For each reference object, a reference gloss image acquisition unit that acquires a reference gloss image indicating the glossiness of the reference object, generated based on light irradiated from the illumination unit and reflected by the reference object,
For each reference gloss image, a calculation unit that calculates a correction value for correcting illumination unevenness based on the reference gloss image;
A selection unit that selects a correction value according to the image clarity of the printed material from the plurality of correction values;
A printed product gloss image acquisition unit that acquires a printed product gloss image indicating the gloss of the printed product, generated based on the light irradiated from the illumination unit and reflected by the printed product;
A correction unit that corrects the printed gloss image based on the selected correction value;
An image processing apparatus comprising: A reception unit for receiving input of image clarity information indicating the image clarity;
The image processing apparatus according to claim 6, wherein the selection unit selects a correction value according to the accepted image clarity. A detection unit for detecting the image clarity from the printed matter;
The image processing apparatus according to claim 6, wherein the selection unit selects a correction value according to the detected image clarity.   The image processing apparatus according to claim 6, further comprising an inspection unit that inspects the printed matter based on the corrected printed matter glossiness image.   The image processing apparatus according to claim 6, further comprising a display control unit that displays an image based on the corrected printed material glossiness image. A reference gloss image acquisition step for acquiring a reference gloss image indicating the gloss of the reference object, which is generated based on the light emitted from the illumination unit and reflected by the reference object;
A calculation step of calculating a correction value for correcting illumination unevenness based on the reference glossiness image;
A correction step of correcting the correction value based on the image clarity of the printed matter;
A printed matter glossiness image obtaining step for obtaining a printed matter glossiness image indicating the glossiness of the printed matter, which is generated based on light irradiated from the illumination unit and reflected by the printed matter;
A correction step of correcting the printed gloss image based on the corrected correction value;
An image processing method including: For each reference object, a reference gloss image acquisition step for acquiring a reference gloss image indicating the glossiness of the reference object, generated based on light irradiated from the illumination unit and reflected by the reference object,
A calculation step for calculating a correction value for correcting illumination unevenness for each reference gloss image based on the reference gloss image;
A selection step of selecting a correction value according to the image clarity of the printed material from the plurality of correction values;
A printed matter glossiness image obtaining step for obtaining a printed matter glossiness image indicating the glossiness of the printed matter, which is generated based on light irradiated from the illumination unit and reflected by the printed matter;
A correction step of correcting the printed gloss image based on the selected correction value;
An image processing method including: A reference gloss image acquisition step for acquiring a reference gloss image indicating the gloss of the reference object, which is generated based on the light emitted from the illumination unit and reflected by the reference object;
A calculation step of calculating a correction value for correcting illumination unevenness based on the reference glossiness image;
A correction step of correcting the correction value based on the image clarity of the printed matter;
A printed matter glossiness image obtaining step for obtaining a printed matter glossiness image indicating the glossiness of the printed matter, which is generated based on light irradiated from the illumination unit and reflected by the printed matter;
A correction step of correcting the printed gloss image based on the corrected correction value;
A program that causes a computer to execute. For each reference object, a reference gloss image acquisition step for acquiring a reference gloss image indicating the glossiness of the reference object, generated based on light irradiated from the illumination unit and reflected by the reference object,
A calculation step for calculating a correction value for correcting illumination unevenness for each reference gloss image based on the reference gloss image;
A selection step of selecting a correction value according to the image clarity of the printed material from the plurality of correction values;
A printed matter glossiness image obtaining step for obtaining a printed matter glossiness image indicating the glossiness of the printed matter, which is generated based on light irradiated from the illumination unit and reflected by the printed matter;
A correction step of correcting the printed gloss image based on the selected correction value;
A program that causes a computer to execute.