Image processing device, image processing method, and program

Abstract

To appropriately create a color conversion parameter corresponding to an input color space of image data.SOLUTION: An image processing apparatus reads the color of a printed material on which a predetermined density pattern is formed, acquires the color characteristics of a first image forming apparatus that has output the printed material, and detects, from the printed material, characteristics related to the printed material. The image processing apparatus specifies an input color space corresponding to the printed material output from the first image forming apparatus based on the detected characteristics related to the printed material. Based on the acquired color characteristics of the first image forming apparatus, the image processing apparatus creates, in a second image forming apparatus, a color conversion parameter corresponding to the specified input color space and reproducing the color characteristics of the first image forming apparatus.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a color adjustment technique in a printer that prints digital image data. [Background technology]

[0002] When replacing or purchasing an image processing device capable of so-called full-color printing, there is a demand to inherit the color of the printed matter printed by the image processing device before replacement or the existing image processing device in the replaced or additionally purchased image processing device. Here, the target printing device such as the image processing device before replacement or the existing image processing device is called the "target device", and the printing device that adjusts the printed matter such as the image processing device after replacement or the additionally purchased image processing device is called the "adjustment device". When performing color matching between the above-mentioned different devices, the printed matter output from the target device is read to obtain the color characteristics of the target device, and color conversion parameters of the adjustment target device are created based on the obtained color characteristics of the target device. By using the created color conversion parameters of the adjustment target device, the input image data of a specified color space is converted into image data of a color space for printing, and a printed matter having the same color as the printed matter printed by the target device is output. Patent Document 1 discloses a technology for applying color conversion parameters to image data input in another color space. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-110724 A Summary of the Invention [Problem to be solved by the invention]

[0004] When creating color conversion parameters for a device to be adjusted, if the input color space of image data differs between the color characteristics of the target device and the color conversion parameters, the color tones will differ between the printed matter output from the device to be adjusted and the printed matter output from the target device.

[0005] The present disclosure provides a technique for appropriately creating color conversion parameters that correspond to an input color space of image data. [Means for solving the problem]

[0006] The image processing device according to the present disclosure includes an acquisition means for reading the color of a printed matter on which a predetermined density pattern is formed, and acquiring color characteristics of a first image forming device that output the printed matter, a detection means for detecting characteristics related to the printed matter from the printed matter, a specification means for specifying an input color space corresponding to the printed matter output by the first image forming device based on the characteristics related to the printed matter detected by the detection means, and a specification means for specifying an input color space corresponding to the printed matter output by the first image forming device based on the color characteristics of the first image forming device acquired by the acquisition means. before Corresponding to the input color space specified by the specifying means, In the second image forming apparatus and creating means for creating color conversion parameters that reproduce the color characteristics of the first image forming apparatus. Effect of the Invention

[0007] According to the present disclosure, it is possible to appropriately create color conversion parameters that correspond to the input color space of image data. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a block diagram showing an example of a hardware configuration of the image forming system. [Diagram 2] 11 is a diagram showing an example of a sequence of a color matching profile creation process in an image forming system. [Diagram 3] FIG. 13 is a diagram showing an example of a color characteristic chart. [Figure 4]13 is a diagram showing an example of a UI screen for executing a color matching profile creation process on a target device. FIG. [Diagram 5] FIG. 13 is a diagram showing an example of a UI screen displayed when a color characteristic chart is loaded. [Figure 6] 13 is a diagram showing an example of a UI screen displayed when an input color space of a color characteristic chart is determined. FIG. [Figure 7] 13 is a diagram showing an example of a UI screen displayed when inputting the name of a color matching profile. FIG. [Figure 8] FIG. 11 is a diagram showing an example of a UI screen for making print settings. [Figure 9] FIG. 13 is a diagram showing an example of a UI screen for setting a color matching profile for CMYK. [Figure 10] 13 is a flowchart showing the flow of a process for creating a color matching profile for a target device. [Figure 11] 10 is a flowchart showing a process for detecting features of a color characteristic chart of a target device. [Figure 12] 10 is a flowchart showing the flow of a process for detecting a patch area of ​​a color characteristic chart of a target device. [Figure 13] 11A and 11B are diagrams illustrating a method for detecting edge coordinates of a color characteristic chart. [Figure 14] 13A and 13B are diagrams illustrating an example of detection of edge coordinates of a color characteristic chart. [Figure 15] 11A and 11B are diagrams illustrating a method for detecting edge coordinates of a patch of a color characteristic chart. [Figure 16] 11A and 11B are diagrams illustrating an example of first differential signal values ​​and an example of autocorrelation coefficient data. [Figure 17] 10 is a flowchart showing a process for detecting features of a color characteristic chart of a target device. [Figure 18] FIG. 13 is a diagram showing an example of a color characteristic chart. [Figure 19] 10 is a flowchart showing a process for detecting features of a color characteristic chart of a target device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Prior to describing the embodiments of the present invention, an overview of a technology for matching the color tones of printed matter between different devices by adjusting a color characteristic profile will be described.

[0010] There is known a profile creation tool for matching the color of a printed matter produced by a device to be adjusted to the color of a printed matter produced by a target device. The profile creation tool first creates a color characteristic chart in which there are multiple image areas with the same color value within a rectangular area called a patch sampled in the sRGB space, which is one of the color spaces independent of the color space of the device. The user operates the tool to print the file of the created color characteristic chart on the target device and measure the color of the printed result, and then the tool creates a color characteristic chart in the LRGB space, which is one of the device-independent color spaces that is visually uniform considering the visual characteristics of humans. * a * b * A measurement file is generated that is expressed as values.

[0011] By loading the generated measurement file into the profile creation tool, you can determine how the target device will represent each color in sRGB. * a * b * A color matching profile that expresses how the value is converted (sRGB → L * a * b * When the created color matching profile is set for the device to be adjusted, if the color space of the input image data is sRGB color space, the created color matching profile is applied to the input image data, and the L * a * b * The image data is converted into L * a * b * The image data of the values ​​is converted to CMYK, a color space that is device-dependent, inside the device being adjusted and printed. Through this process, the device being adjusted is able to output printed material that reproduces the colors of the target device.

[0012] In the technology of Patent Document 1, for example, when image data is input in AdobeRGB proposed by Adobe Systems, the AdobeRGB color space is converted to sRGB color space once, and a color matching profile is applied before printing. This allows image data input in AdobeRGB color space to be printed in a state where the device being adjusted reproduces the color characteristics of the target device. Similarly, when image data configured in CMYK color space is input, a profile (CMYK→L) that converts to the standard color specifications of each country, such as JapanColor or FOGRA, is used. * a * b * profile) to convert the CMYK color space to L * a * b * Then, using a given calculation, convert the converted L * a * b * By converting image data from the sRGB color space to the sRGB color space, the created color matching profile (sRGB→L * a * b * Profile) can be applied.

[0013] However, even if a color matching profile that converts image data from the CMYK color space to the sRGB color space to represent the standard color specifications of each country is applied to the device to be adjusted, degradation of image quality may occur in the printed material output from the device to be adjusted. The reason for this is that the color space expressed in CMYK, which is device-dependent, is narrower than the device-independent sRGB color space.

[0014] sRGB color space to L * a * b * When color space conversion is performed to the CMYK color space for printing on a printer via a color space, perceptual gamut compression is often performed. Therefore, a color matching profile (sRGB → L* a * b * When color conversion is performed via a color matching profile, image data with a very narrow color gamut is generated. In other words, the color matching profile compresses a wide color gamut into a narrow color gamut, but when a color matching profile is applied to a narrow color gamut, it is converted into color values ​​expressed in an even narrower color gamut. As a result, the converted image data is printed as a dull image. For this reason, it was necessary to create an appropriate color matching profile that corresponds to the input color space of the color characteristic chart that indicates the color characteristics of the target device.

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the following embodiments do not limit the present disclosure related to the claims, and not all of the combinations of features described in the present embodiments are necessarily essential to the solution of the present disclosure. Note that the same components are given the same reference numbers and descriptions are omitted.

[0016] [Embodiment 1] In this embodiment, the color of a printed matter (color characteristic chart) on which a predetermined density pattern is formed is read, the color characteristics of the target device that output the printed matter are acquired, and characteristics related to the printed matter are detected from the printed matter. Based on the detected characteristics related to the printed matter, an input color space corresponding to the printed matter output by the target device is identified. Then, based on the acquired color characteristics of the target device, a color matching profile that corresponds to the identified input color space and reproduces the color characteristics of the target device is created in the adjustment target device. That is, a mode is described in which the input color space of the color characteristic chart is determined based on the detected characteristics related to the color characteristic chart, and a color matching profile is appropriately created depending on the determined input color space. The color matching profile can also be called a color conversion parameter.

[0017] Fig. 1 is a block diagram showing an example of the configuration of an image forming system according to this embodiment. As shown in Fig. 1, the image forming system according to this embodiment includes a device 100 to be adjusted, a target device 130, an external processing device 115, and a PC 150. These devices are connected to each other via a network 101 so that they can transmit and receive data to and from each other. Note that the device 100 to be adjusted and the target device 130 can be, for example, a copier, a multifunction machine, or an image forming device capable of color printing by an electrophotographic method, such as a laser printer or a facsimile machine with a separate scanner.

[0018] The adjustment target device 100 is an image processing device, and includes a device control unit 102, a user interface 104, an image reading unit 108, a display 109, an image output unit 110, a paper feed unit 112, and a paper output unit 113. Hereinafter, the user interface will be referred to as UI. The device control unit 102 includes a CPU 105, a RAM 106, a storage unit 107, and an image processing unit 103 including an ASIC that processes image data. The image output unit 110 includes a CPU 111 and a RAM 114.

[0019] The UI 104 has input / output devices such as a keyboard, a mouse, and a touch panel, displays a UI screen, and accepts input of various setting values, designated values, and the like by the user.

[0020] The CPU (Central Processing Unit) 105 is an arithmetic processing device that executes an initial program stored in the memory unit 107, reads out a main program from the memory unit 107, and loads it into the RAM 106. The RAM (Random Access Memory) 106 is used as a main memory for storing programs and for working. The CPU 105 controls the device control unit 102 in accordance with the main program. The device control unit 102 is a controller board, and the devices of the CPU 105, RAM 106, memory unit 107, and image processing unit 103 are implemented on the device control unit 102.

[0021] The image reading unit 108 illuminates a bundle of documents or a single document with a light source (not shown) and forms an image of the light reflected from the document on a solid-state image sensor such as a CCD (Charge Coupled Device) sensor through a lens. Then, the image reading signal obtained from the solid-state image sensor is obtained as multi-value image data of red, green, and blue (hereinafter referred to as R, G, and B). The image reading unit 108 may include an auto document feeder (hereinafter referred to as ADF) that continuously reads multiple pages of paper documents and converts them into image data.

[0022] The image processing unit 103 performs image processing on print data transmitted from a printer driver 154 of the PC 150, which will be described in detail later, via the network 101, and image data acquired by the image reading unit 108, etc. The image processing unit 103 will be described in detail later.

[0023] The storage unit 107 stores image data processed by the image processing unit 103, print data transmitted from the printer driver 154 of the PC 150, a DB (database) that holds color vision information for each user (described later), and a DB that holds group setting information for each user, etc. The storage unit 107 is, for example, a hard disk drive or a ROM (Read Only Memory).

[0024] The display 109 is, for example, a liquid crystal display (LCD), and is used to display the setting state of the image processing device 100, the status of processing being performed, error states, etc. The display 109 may be integrated with the UI 104.

[0025] The image output unit 110 is connected to the device control unit 102, and is a printer that forms an image on a recording medium such as paper using color toners such as C, M, Y, and K based on image data processed by the image processing unit 103. C represents cyan, M represents magenta, Y represents yellow, and K represents black. The image output unit 110 is a controller board, and devices such as a CPU 111 and a RAM 114 are mounted on the image output unit 110. The image output unit 110 is controlled by the CPU 111, and has a paper feed unit 112 that feeds paper on which an image is formed, and a paper discharge unit 113 that discharges the paper on which the image is formed.

[0026] The external processing device 115 has a device control unit 120. The device control unit 120 has an image processing unit 116, a CPU 117, a RAM 118, and a storage unit 119. The CPU 117 is an arithmetic processing device, and executes an initial program stored in the storage unit 119, reads a main program from the storage unit 119, and develops it in the RAM 118. The RAM 118 is used as a main memory for storing programs and for working. The CPU 117 controls the device control unit 120 according to the main program. The device control unit 120 is a controller board, and the devices of the CPU 117, the RAM 118, the storage unit 119, and the image processing unit 116 are implemented on the device control unit 120. Note that some functions of the adjustment target device 100 can be executed by the external processing device 115 by mutually communicating via the network 101.

[0027] The above-described device 100 to be adjusted is an example, and the image processing device 100 may be configured not to include the image reading unit 108. In addition, some functions of the device 100 to be adjusted may be executed by an external processing device 115 by mutual communication via the network 101. The external processing device 115 may be implemented by a computer device such as a server, or may be implemented by a cloud server on the Internet. Other configurations may be provided as necessary.

[0028] The target device 130 is an image processing device that outputs a printed material that forms an image having target color characteristics for the device 100 to be adjusted, and has the same hardware configuration as the device 100 to be adjusted, so a description of the hardware configuration of the target device 130 will be omitted.

[0029] The PC 150 is a PC (Personal Computer) used by a user, and includes a CPU 151, a RAM 152, a storage unit 153, and a printer driver 154. The PC 150 is capable of transmitting and receiving data to and from the adjustment target device 100, the target device 130, and the external processing device 115 via the network 101.

[0030] CPU 151 executes an initial program stored in storage unit 153, reads out a main program from storage unit 153, and loads it into RAM 152. RAM 152 is used as a main memory for storing programs and for working. CPU 151 controls applications and printer driver 154 used by the user in accordance with the main program.

[0031] The printer driver 154 transmits image data expanded by an application used by the user and print settings set by the user when printing as print data to the adjustment target device 100 or the target device 130.

[0032] <Processing flow of the entire image forming system> FIG. 2 is a sequence diagram showing a process flow when a color characteristic chart is printed by a user in a target device in the image forming system according to the present embodiment, and a color matching profile is created in a device to be adjusted using the printed color characteristic chart. Here, the description will be centered on the interaction between the user and the device. Each process shown in FIG. 2 is executed by a user 201 operating the PC 150, the target device 130, and the device to be adjusted 100. At this time, the process of the PC 150 is executed by developing the program code stored in the storage unit 153 in the RAM 152, and controlling the device control unit (not shown) by the CPU 151. In addition, the process of the device to be adjusted 100 is executed by developing the program code stored in the storage unit 107 in the RAM 106, and controlling the device control unit 102 by the CPU 105. In addition, the process of the target device 130 is executed by developing the program code stored in the storage unit 137 in the RAM 136, and controlling the device control unit 132 by the CPU 135. The data created during the color matching profile creation process in the adjustment target device 100 is temporarily stored in the RAM 106 or the storage unit 107. Below, the exchanges between the devices will be explained in chronological order according to the sequence diagram in Fig. 2. In the following explanation, the symbol "SQ" represents a step.

[0033] First, in SQ210, the user 201 instructs the PC 150 to print image data of the color characteristic chart (also called color characteristic chart data) on the target device 130. Then, in SQ211, upon receiving the print instruction of SQ210, the PC 150 develops the image data of the color characteristic chart using a corresponding application. In this embodiment, the input color space expressing the color characteristic chart is CMYK or RGB. Therefore, in the process of SQ210, a print instruction is issued for color characteristic chart data whose input color space is CMYK or RGB. In the process of SQ211, color characteristic chart data corresponding to the input color space instructed in SQ210 is developed.

[0034] Here, the configuration of the color characteristic chart will be explained using the drawings. FIG. 3 is a diagram showing an example of the configuration of a color characteristic chart printed to check the color characteristics of a target device. As will be described in detail later, the color characteristics of an image processing device (target device) can be checked by measuring the color of the color characteristic chart. As shown in FIG. 3, the color characteristic chart has images of multiple rectangular areas (M×N in FIG. 3), and is a printed matter on which a predetermined density pattern is formed. The images of the rectangular areas are images having the same signal values ​​(RGB values ​​or CMYK values) within the area, and are called patches.

[0035] In this embodiment, the signal values ​​(RGB values) of the patches of the color characteristic chart in which the input color space is RGB are represented by signal values ​​sampled at equal intervals in the sRGB color space, which is one of the color spaces independent of the color space of the device. For example, when the signal values ​​(RGB values) of the patches in the RGB color characteristic chart are represented by 8 bits for each of R, G, and B and sampled so that the signal value interval is 32, the number of samples for each of R, G, and B is 9. Therefore, the RGB color characteristic chart is composed of a total of 9 x 9 x 9 = 729 patches. The sRGB color space is an international standard for color spaces established by the IEC (International Electrotechnical Commission), and is a color space established to ensure color reproducibility between different environments such as input / output devices.

[0036] On the other hand, in this embodiment, the signal values ​​(CMYK values) of the patches of the color characteristic chart in which the input color space is CMYK are represented by signal values ​​sampled at equal intervals in the CMYK color space, which is one of the color spaces dependent on the color space of the device. For example, when the signal values ​​(CMYK values) of the patches in the CMYK color characteristic chart are represented by 8 bits for each of C, M, Y, and K, and sampled so that the signal value interval is 32, the number of samples is 9 for each of C, M, Y, and K. Therefore, the color characteristic chart for CMYK is composed of a total of 9 x 9 x 9 x 9 = 6561 patches.

[0037] The difference between the RGB color characteristic chart and the CMYK color characteristic chart described above will be explained using Table 1. Table 1 shows the total number of color characteristic charts (P) and the number of patches required to create a color matching profile for the RGB and CMYK color characteristic charts. Furthermore, Table 1 also shows the number of rows of patches per color characteristic chart (M) indicating the number of patches formed in the row direction on one printed sheet, and the number of columns of patches per color characteristic chart (N) indicating the number of patches formed in the column direction on one printed sheet. Table 1 also shows the number of patches per color characteristic chart (M×N) indicating the total number of patches formed on one printed sheet, and the number of patches on all pages of the color characteristic chart (P×M×N) indicating the total number of patches formed on all pages of the printed sheet. The difference between these items is the difference between the characteristics of the RGB color characteristic chart and the characteristics of the CMYK color characteristic chart. For example, when the input color space is CMYK, the number of color characteristic charts required to create a color matching profile is 8, and the number of patches required to create a color matching profile is 6561. On the other hand, when the input color space is RGB, the number of color characteristic charts required to create a color matching profile is 1, and the number of patches required to create a color matching profile is 729.

[0038] [Table 1]

[0039] In this embodiment, the image data of the color characteristic chart is assumed to be in a format such as TIFF (Tagged Image File Format) or PDF (Portable Document Format). The image data of the color characteristic chart is not limited to such a format. The image data of the color characteristic chart may be in a format that can be read (developed) by applications running on the PC 150, the target device 130, and the adjustment target device 100, which are the objects of operation by the user.

[0040] In SQ212, PC 150 transmits the image data of the color characteristic chart developed in SQ211 and setting information related to colors that can be set by printer driver 154 to target device 130 via printer driver 154 and network 101. In this embodiment, the setting information that can be set by printer driver 154 includes print setting information related to color processing such as density adjustment and color mode. It is assumed that the setting information reflects print settings related to color processing that the user normally uses when printing with target device 130.

[0041] In SQ213, target device 130 performs color conversion processing on the image data of the color characteristic chart received from PC 150 in SQ212 in accordance with the color setting information received from PC 150 in SQ212. Then, target device 130 prints using the image data after color conversion processing in image output unit 140. Therefore, the printed matter output from image output unit 140 is a recording medium on which the color characteristic chart corresponding to the input color space specified in SQ210 is printed.

[0042] In SQ214, when the printing process of the color characteristic chart executed in SQ213 is completed, the target device 130 notifies the PC 150 that the printing process of the color characteristic chart in the target device 130 is completed.

[0043] In SQ215, upon receiving from target device 130 a notification that the printing executed in SQ214 has been completed, PC 150 notifies user 201 via the application that the printing process has been completed in target device 130.

[0044] In SQ220, the user 201 instructs the adjustment target device 100 to execute a color matching profile creation process for the adjustment target device 100 (also referred to as a color matching profile creation instruction). The instruction to execute the color matching profile creation process by the user 201 for the adjustment target device 100 is given, for example, via a UI screen displayed on the UI 104. Here, an example of a UI screen for instructing the adjustment target device 100 to execute the color matching profile creation process by the user 201 will be described with reference to the drawings. FIG. 4 is a diagram showing an example of a UI screen for instructing the adjustment target device to execute the color matching profile creation process. FIG. 4(a) shows an operation screen of the adjustment target device 100, which is an initial screen, and FIG. 4(b) shows an operation screen of the adjustment target device 100, which is a screen after the “color matching profile creation” button 407 shown in FIG. 4(a) is pressed. FIG. 4(c) shows an operation screen of the adjustment target device 100, which is a screen after the “PS / PDF” button 413 shown in FIG. 4(b) is pressed.

[0045] The UI screen 401 is an operation screen displayed on the UI 104. The UI screen 401 is an initial screen for instructing the execution of various functions of the device 100 to be adjusted, and has buttons 402 to 407 corresponding to various functions, as shown in FIG. 4(a). The UI screen 401 has a "Copy" button 402, a "Print" button 403, a "Fax" button 404, a "Scan and Send" button 405, a "Direct Print" button 406, and a "Create Color Matching Profile" button 407. The buttons 402 to 407 are buttons pressed by the user when executing a function of the device 100 to be adjusted, and the function corresponding to the pressed button is executed according to a program. The timing for executing the color matching profile creation process is when the button 407 is pressed by the user. In this embodiment, a mode in which an instruction to execute various functions of the image processing device is given in the form of a button is shown, but is not limited to this. An instruction to execute various functions may be given in the form of a list.

[0046] The UI screen 411 is a screen displayed on the UI 104 after the user presses the "Create color matching profile" button 407. As shown in FIG. 4B, the UI screen 411 has a "PCL" button 412, a "PS / PDF" button 413, and a "Back" button 414. The buttons 412 and 413 are pressed when the user executes the print type for which the color matching profile is to be created, and the pressed button executes the creation process of the corresponding print profile according to the program. In the color matching profile creation process according to this embodiment, the input color space of the image data is targeted for prints that can handle both RGB and CMYK, so PS (Post Script) and PDF listed in the "PS / PDF" button 413 are targeted. Therefore, when the user presses the "PS / PDF" button 413, the adjustment target device 100 executes the color matching profile creation process, which will be described in detail later. It should be noted that PCL (Printer Control Language), which is the print type listed in the "PCL" button 412, is a page description language developed by Hewlett-Packard, and is a print that supports only RGB as the input color space of image data.

[0047] When the "return" button 414 is pressed by the user, the adjustment target device 100 stops the execution of the color matching profile creation process, and the screen displayed on the UI 104 transitions to the UI screen 401 of FIG. 4(a), which is the initial screen.

[0048] The UI screen 421 is a screen displayed on the UI 104 after the user presses the "PS / PDF" button 413. As shown in FIG. 4C, the UI screen 421 has a "Create color matching profile" button 422, a "Delete color matching profile" button 423, and a "Back" button 424. The "Create color matching profile" button 422 is a button pressed by the user when creating a color matching profile in the device 100 to be adjusted. The "Delete color matching profile" button 423 is a button pressed by the user when deleting a color matching profile that has been created so far in the device 100 to be adjusted. In this embodiment, when the "Create color matching profile" button 422 is pressed by the user, a color matching profile creation process, which will be described later, is executed.

[0049] When the "return" button 424 is pressed by the user, the adjustment target device 100 stops the execution of the color matching profile creation process, and the screen displayed on the UI 104 transitions to the UI screen 401 of FIG. 4(a), which is the initial screen.

[0050] Returning to the explanation of Fig. 2, in SQ221, when the adjustment target device 100 receives the color matching profile creation instruction of SQ220, it performs a scan process on the color characteristic chart, which is a printout printed by the target device 130 in SQ213, using an ADF (not shown) of the image reading unit 108. Then, by measuring the color of the scanned image obtained by the scan process using a colorimeter (not shown), the adjustment target device 100 acquires color values, which are colorimetric data of the color characteristic chart.

[0051] When performing the scan of SQ221, the adjustment target device 100 first instructs (notifies) the user 201 to place the color characteristic chart of the target device 130 printed by the target device 130 on the ADF of the adjustment target device 100 in SQ213. The instruction to the user to place the color characteristic chart is given via, for example, a UI screen displayed on the UI 104.

[0052] Here, an example of a UI screen that instructs the user to place the color characteristic chart of the target device 130 on the ADF of the adjustment target device 100 when performing a scan will be described with reference to the drawings. Fig. 5 shows an example of a UI screen that is displayed when reading a color characteristic chart, Fig. 5(a) shows an example of a UI screen that is displayed when the reading process has not been performed, and Fig. 5(b) shows an example of a UI screen that is displayed when the reading process has not been successful.

[0053] 5(a) is a screen displayed on the UI 104 when a color matching profile creation instruction is received, and includes a message 502, a "Load Chart" button 503, and a "Back" button 504. The message 502 includes a message instructing (notifying) the user to set a color characteristic chart printed by a target device in the feeder.

[0054] The "Read Chart" button 503 is a button pressed by the user when causing the device 100 to execute a scan process after the color characteristic chart printed by the target device 130 is placed on the ADF of the device 100 to be adjusted. When the "Read Chart" button 503 is pressed by the user, the device 100 to be adjusted issues a command to the image reading unit 108 to execute a scan process, and executes a process of reading the color characteristic chart placed on the ADF of the device 100 to be adjusted. Even if the user presses the "Read Chart" button 503 in a state in which a color characteristic chart is not placed on the ADF of the device 100 to be adjusted, the device 100 to be adjusted may not cause the image reading unit 108 to execute a scan process.

[0055] The "Back" button 504 is a button that is pressed by the user when canceling the scanning process of SQ221. When the "Back" button 504 is pressed by the user, the adjustment target device 100 cancels the execution of the color matching profile creation process, and the screen displayed on the UI 104 transitions to the UI screen 401 of FIG. 4(a), which is the initial screen.

[0056] 5(b) is a screen that is displayed on the UI 104 when the color characteristic chart loading process is unsuccessful, and includes a message 512, a "Load Chart" button 513, and a "Back" button 514. The message 512 includes a message that instructs (notifies) the user to reset the color characteristic chart printed by the target device in the feeder.

[0057] The "Read Chart" button 513 is a button pressed by the user when causing the device 100 to execute a scan process after the color characteristic chart printed by the target device 130 is placed on the ADF of the device 100 to be adjusted. When the "Read Chart" button 513 is pressed by the user, the device 100 to be adjusted issues a command to the image reading unit 108 to execute a scan process, and re-executes a process of reading the color characteristic chart placed on the ADF of the device 100 to be adjusted. Even if the user presses the "Read Chart" button 513 in a state where a color characteristic chart is not placed on the ADF of the device 100 to be adjusted, the device 100 to be adjusted may not cause the image reading unit 108 to execute a scan process.

[0058] The "Back" button 514 is a button pressed by the user when canceling the scanning process of SQ221, similar to the "Back" button 504. When the "Back" button 514 is pressed by the user, the adjustment target device 100 cancels the execution of the color matching profile creation process, and the screen displayed on the UI 104 transitions to the UI screen 401 in FIG. 4(a), which is the initial screen.

[0059] In SQ222, the adjustment target device 100 detects the characteristics of the items shown in Table 1 based on the colorimetric data of the color characteristic chart obtained in the scan process of SQ221. Then, the adjustment target device 100 executes a process of classifying (determining) whether the input color space of the scanned color characteristic chart is RGB or CMYK based on the detected characteristics. The method of detecting the characteristics of the color characteristic chart for the items shown in Table 1 and executing the process of classifying whether the input color space of the color characteristic chart is RGB or CMYK will be described later in detail.

[0060] When the process of classifying the input color space is completed, the adjustment target device 100 provides the user 201 with a UI screen for receiving an instruction to create a color matching profile according to the classification result, and executes a process of creating a color matching profile corresponding to the received creation instruction. The UI screen for receiving an instruction to create a color matching profile is provided to the user via, for example, the UI 104 that displays the UI screen.

[0061] When the processing of SQ222 gives a classification result that the input color space is CMYK, in SQ223, the adjustment target device 100 displays a UI screen on the UI 104 for receiving an instruction to create a color matching profile for CMYK. When the adjustment target device 100 receives an instruction to create a color matching profile for CMYK, it executes a color matching profile creation process for CMYK using the color values ​​(colorimetric values) of the color characteristic chart obtained by color measurement, and creates a color matching profile for CMYK. The color values ​​of the color characteristic chart are also called patch reading values. The process of creating a color matching profile for CMYK will be described in detail later.

[0062] Here, an example of a UI screen for receiving an instruction to create a color matching profile will be described with reference to the drawings. Fig. 6 is a diagram showing an example of a UI screen displayed when the input color space of the color characteristics chart is determined. Fig. 6(a) shows an example of a UI screen displayed when the input color space of the color characteristics chart is CMYK, and Fig. 6(b) shows an example of a UI screen displayed when the input color space of the color characteristics chart is RGB.

[0063] 6(a) is a screen that is displayed on the UI 104 when the input color space of the color characteristic chart is classified as CMYK, and includes a message 602, a "Back" button 603, and an "OK" button 604. The message 602 includes a message that indicates to the user that the color characteristic chart has been successfully loaded and that a color matching profile for CMYK will be created.

[0064] The "Back" button 603 is a button pressed by the user when canceling the color matching profile creation process of SQ223. When the "Back" button 603 is pressed by the user, the adjustment target device 100 cancels the execution of the color matching profile creation process and transitions the screen displayed on the UI 104 to the UI screen 401 of FIG. 4(a), which is the initial screen.

[0065] An "OK" button 604 is a button pressed by the user when causing the adjustment target device 100 to execute a process for creating a color matching profile for CMYK. When the user presses the "OK" button 603, the adjustment target device 100 executes a process for creating a color matching profile for CMYK, and creates a color matching profile for CMYK, which is a color conversion parameter. As the color matching profile for CMYK, for example, a lookup table such as that shown in Table 2 below is created.

[0066] [Table 2]

[0067] When the processing of SQ222 gives a classification result that the input color space is RGB, in SQ224, the adjustment target device 100 displays a UI screen on the UI 104 for receiving an instruction to create a color matching profile for RGB. Upon receiving the instruction to create a color matching profile for RGB, the adjustment target device 100 executes a process to create a color matching profile for RGB using the color values ​​(colorimetric values) of the patches of the color characteristic chart obtained by color measurement, and creates a color matching profile for RGB. The process of creating a color matching profile for RGB will be described in detail later.

[0068] 6(b) is a screen that is displayed on the UI 104 when the input color space of the color characteristic chart is classified as RGB, and includes a message 612, a "Back" button 613, and an "OK" button 614. The message 612 includes a message that indicates to the user that the color characteristic chart has been successfully loaded and that a color matching profile for RGB will be created.

[0069] The "Back" button 613 is a button pressed by the user when canceling the color matching profile creation process of SQ224. When the "Back" button 613 is pressed by the user, the adjustment target device 100 cancels the execution of the color matching profile creation process and transitions the screen displayed on the UI 104 to the UI screen 401 of FIG. 4(a), which is the initial screen.

[0070] The "OK" button 614 is a button pressed by the user when causing the adjustment target device 100 to execute a process for creating a color matching profile for RGB. When the user presses the "OK" button 614, the adjustment target device 100 executes a process for creating a color matching profile for RGB, and creates a color matching profile for RGB, which is a color conversion parameter. As the color matching profile for RGB, for example, a lookup table such as that shown in Table 3 below is created.

[0071] [Table 3]

[0072] In SQ225, the adjustment target device 100 stores (preserves) the color matching profile created in SQ223 or SQ224 in the storage unit 107, and sets it in a state where it can be used by the user.

[0073] When the created color matching profile is stored in the storage unit 107, the name of the created color matching profile can be set by the user. An example of a UI screen displayed when the user 201 inputs the name of the color matching profile at the time of storage will be described with reference to the drawings. FIG. 7 is a diagram showing an example of a UI screen displayed when the name of the profile at the time of storage is input. The UI screen 701 shown in FIG. 7 is a screen displayed on the UI 104 when the creation of the color matching profile is completed, and has a message 702, a text box 703, an "OK" button 704, and a "Cancel" button 705. The message 702 includes a message instructing (notifying) the user to input the name of the color matching profile.

[0074] The text box 703 is a text box for inputting and displaying a name for storing the created color matching profile. When the text box 703 is pressed by the user 201, a UI screen for input (not shown), such as a software keyboard, is displayed, and the name of the color matching profile can be input by a user operation on the UI screen for input. The method for inputting the name of the color matching profile is not limited to this, and may be a user operation on a keyboard of the UI 104 or an external input device.

[0075] The “OK” button 704 is a button that is pressed by the user when inputting the name of the color matching profile into the text box 703 is completed and confirmed. When the “OK” button 704 is pressed by the user, the adjustment target device 100 saves the created color matching profile according to the name (setting name) displayed in the text box 703.

[0076] The "Cancel" button 705 is a button that is pressed by the user when canceling the color matching profile creation process of SQ223 or SQ224. When the "Cancel" button 705 is pressed by the user, the adjustment target device 100 cancels the execution of the color matching profile creation process and transitions the screen displayed on the UI 104 to the initial screen, that is, the UI screen 401 in FIG. 4(a), which is the initial screen.

[0077] An example of a UI screen showing print settings provided by the printer driver 154 before and after the process of creating a color matching profile for CMYK according to this embodiment will be described with reference to the drawings. Figures 8(a) and 8(b) are diagrams showing an example of a UI screen for print settings provided by the printer driver 154 and displayed on a display device (not shown) of the PC 150 when print settings related to the color mode are made with the printer driver 154.

[0078] The UI screen 801 shown in FIG. 8(a) is a screen showing a state before the color matching profile creation process for CMYK is performed. On the other hand, the UI screen 811 shown in FIG. 8(b) is a screen showing a state after the color matching profile creation process for CMYK is performed. Note that the UI screen 811 after the color matching profile creation process for CMYK is performed is a state in which the latest information on the print settings of the adjustment target device 100 (hereinafter also referred to as the latest setting information) has been acquired from the adjustment target device 100. In this embodiment, the printer driver 154 acquires the latest setting information of the adjustment target device 100 from the adjustment target device 100 when receiving an instruction from the user 201 to acquire the latest setting information. The timing of acquiring the latest setting information is not limited to the timing of receiving the instruction from the user, and may be any timing such as the timing of using the printer driver 154 or the timing of the lapse of a predetermined period of time as long as the latest setting information can be acquired. The display device (not shown) of the PC 150 is, for example, a liquid crystal display, and displays the UI screen and the like.

[0079] The UI screen 801 has a list box 802 for setting a color mode, a list box 803 for setting an RGB input profile, and a list box 804 for setting a CMYK simulation profile. The UI screen 801 further has an “OK” button 805 and a “Cancel” button 806.

[0080] The UI screen 811 has a list box 812 for setting a color mode, a list box 813 for setting an RGB input profile, and a list box 814 for setting a CMYK simulation profile. The UI screen 811 further has an “OK” button 815 and a “Cancel” button 816.

[0081] List boxes 802 and 812 are list boxes used when the user sets a color mode for printing on the adjustment target device 100. Depending on the set color mode, the printer driver 154 and image processing in the image processing device 100 are switched. When the user sets the color mode, setting items (not shown) are expanded in the list boxes 802 and 812, and each setting item can be selected.

[0082] The list boxes 803 and 813 are used to select the RGB input profile (sRGB→L * a * b * This is a list box used to set the color profile. If the input color space of the image data to be printed is RGB, the RGB input profile applied during color conversion will change according to the profile that is set. * a * b * The value is L, one of the device-independent color spaces created by the CIE (International Commission on Illumination). * a * b * It is a value in the color space. * a * b *The color space is a device-independent, three-dimensional color space that is visually uniform and takes into account human visual characteristics.

[0083] The list boxes 804 and 814 are used to select the CMYK input profile (CMYK→L) that the user applies to the adjustment target device 100 in color space conversion during printing. * a * b * This is a list box used when setting a CMYK input profile. If the input color space of the image data to be printed is CMYK, the CMYK input profile applied during color conversion will switch depending on the set profile. When a color matching profile for CMYK is saved in SQ225, in this embodiment, the name of the color matching profile is added to list box 814, and the added color matching profile becomes selectable by the user. The CMYK input profile is also called a CMYK simulation profile.

[0084] The "OK" button 805 and the "OK" button 815 are buttons that are pressed when the operation related to the print settings of the printer driver 154 is completed and the user instructs the adjustment target device 100 to perform print processing. When the "OK" button 805 and the "OK" button 815 are pressed by the user, the display of the UI screen 801 and the UI screen 811 is terminated, each setting item related to printing is applied to the adjustment target device 100, and processing for printing is executed.

[0085] The "Cancel" button 806 and the "Cancel" button 816 are buttons that are pressed by the user when canceling printing by the adjustment target device 100. When the "Cancel" button 806 and the "Cancel" button 816 are pressed by the user, the display of the UI screen 801 and the UI screen 811 is terminated, and the printing process by the adjustment target device 100 is canceled.

[0086] It is assumed that the background color of the setting items applied at the time of printing is gray for the list boxes 803, 813, 804, and 814. Also, it is assumed that the setting items applied at the time of printing are the items that were set immediately before the display of the UI screen 801 and the UI screen 811 was terminated after the user finished setting.

[0087] An example of a UI screen for setting a profile to be applied to color space conversion in the adjustment target device 100 before and after the process of creating a color matching profile for CMYK according to this embodiment will be described with reference to the drawings. Fig. 9(a) and Fig. 9(b) are diagrams showing UI screens for setting a color matching profile for CMYK.

[0088] The UI screen 901 shown in FIG. 9A is a screen displayed on the UI 104 when setting a color matching profile for CMYK to be applied to color space conversion in the adjustment target device 100. The UI screen 901 is a screen showing the state before the CMYK color matching profile creation process is executed. The CMYK color matching profile is used to convert the color values ​​of the CMYK color space (CMYK values ​​of the input color space) of the image data to be printed into L, * a * b * 9B is a screen displayed on the UI 104 when setting a color matching profile for CMYK to be applied to color space conversion in the adjustment target device 100. The UI screen 911 is a screen showing the state after the CMYK color matching profile creation process has been performed.

[0089] The UI screen 901 has a list box 902, an “OK” button 903, and a “Cancel” button 904. The UI screen 911 has a list box 912, an “OK” button 913, and a “Cancel” button 914.

[0090] List boxes 902 and 912 are list boxes used by the user when setting a profile to be applied to color space conversion during printing for the adjustment target device 100. The color matching profile for CMYK (also called an input profile) to be applied during color space conversion is switched depending on the set profile. When a color matching profile created in SQ225 is set, the name of the color matching profile is added to list box 912, and the added color matching profile becomes selectable by the user. Regarding list boxes 902 and 912, setting items to be applied during printing have a gray background color.

[0091] An "OK" button 903 and an "OK" button 913 are buttons that are pressed when the settings of the CMYK input profile to be applied during color space conversion are completed and the user applies the items set to the adjustment target device 100. When the "OK" button 903 and the "OK" button 913 are pressed by the user, the display of the UI screen 901 and the UI screen 911 is terminated, and the setting items related to each print are applied to the adjustment target device 100.

[0092] The "Cancel" button 904 and the "Cancel" button 914 are buttons that are pressed by the user when canceling the settings of the CMYK input profile applied during color space conversion. When the "Cancel" button 904 and the "Cancel" button 914 are pressed by the user, the display of the UI screen 901 and the UI screen 911 are terminated, and the settings for the adjustment target device 100 are canceled. Therefore, the settings of each item before this setting operation is performed are maintained in the adjustment target device 100.

[0093] Returning to the explanation of Fig. 2, in SQ226, the adjustment target device 100 notifies the user 201 that the color matching profile creation process has ended.

[0094] In SQ230, the user 201 instructs the PC 150 to print the image data that the user 201 wants to print.

[0095] In SQ231, when PC 150 receives a print instruction from SQ230, it uses a corresponding application to expand the image data that user 201 wants to print. In this embodiment, it is assumed that the input color space of the image data that user 201 wants to print is RGB or CMYK, and that the profile saved (set) in SQ225 is in a usable state. Note that in this embodiment, it is assumed that the image data that user 201 wants to print is image data in a format such as TIFF or PDF. The image data that user 201 wants to print is not limited to image data in such a format, and may be image data in a format that can be read (expanded) by an application running on PC 150, which is the target of the user's operation.

[0096] In SQ232, the printer driver 154 of the PC 150 transmits the image data that the user wants to print, expanded in SQ231, and the setting information for using the color matching profile saved in SQ225, to the device 100 to be adjusted via the network 101.

[0097] In SQ233, the adjustment target device 100 performs color space conversion processing using a color matching profile on the image data received from the PC 150 in SQ232 in accordance with the setting information received from the PC 150 in SQ232. If the color matching profile created in SQ223 is set and the input color space of the image data is CMYK, color conversion processing is performed using the color matching profile created in SQ223. If the color matching profile created in SQ224 is set and the input color space of the image data is RGB, color conversion processing is performed using the color matching profile created in SQ224. The adjustment target device 100 then prints at the image output unit 110 using the image data after the color space conversion processing.

[0098] In SQ234, when the printing process of the image data executed in SQ233 is completed, the adjustment target device 100 notifies the PC 150 that the printing process of the image data has been completed in the adjustment target device 100.

[0099] In SQ235, when the PC 150 receives a notification of completion of the printing executed in SQ234 from the adjustment target device 100, the PC 150 notifies the user 201 via the application that the printing process in the adjustment target device 100 has been completed.

[0100] The above is a description of the overall flow of the color matching profile creation process by the image forming system according to the present embodiment.

[0101] (Color matching profile creation process) The color matching profile creation process according to this embodiment will be described with reference to the drawings. FIG. 10 is a flowchart showing the flow of the color matching profile creation process for the target device. The process shown in FIG. 10 is executed when the device 100 to be adjusted receives an instruction from a user to execute the color matching profile creation process. At this time, the process of the device 100 to be adjusted is executed by expanding the program code stored in the storage unit 107 into the RAM 106 and controlling the device control unit 102 by the CPU 105. Note that data created during the process is temporarily stored in the RAM 106 or the storage unit 107. In the following description, the symbol "S" represents a step.

[0102] First, in S1001, the device control unit 102 acquires scanned image data by scanning a color characteristic chart printed by the target device 130 with the image reading unit 108. The acquired scanned image data of the color characteristic chart is used to check the color characteristics of the target device 130. The process of S1001 corresponds to the process performed in SQ221 in FIG. 2.

[0103] In S1002, the device control unit 102 executes a feature detection process of the color characteristic chart for detecting features of the scanned image data obtained in the process of S1001. The features to be detected are as shown in Table 1, and are used to determine whether the input color space of the color characteristic chart is RGB or CMYK. In this embodiment, the number of sheets of the color characteristic chart read in the scan process, the number of patches per sheet of the color characteristic chart, and the number of patches on all pages of the color characteristic chart are detected as the features. Then, the device control unit 102 classifies and identifies the scanned image data as a color characteristic chart in the RGB color space, a color characteristic chart in the CMYK color space, or a color characteristic chart other than the above, using the detected features. Details of the feature detection process of the color characteristic chart according to this embodiment will be described later with reference to the drawings. The process of S1002 corresponds to the process performed in SQ222 of FIG. 2.

[0104] In S1003, the device control unit 102 determines whether or not the RGB color space feature or the CMYK color space feature was detected in S1002. If the determination result indicates that the RGB color space feature or the CMYK color space feature was detected (YES in S1003), the process proceeds to S1005. On the other hand, if the determination result indicates that the RGB color space feature and the CMYK color space feature were not detected, that is, if the determination result indicates that a non-target feature was detected (NO in S1003), the process proceeds to S1004.

[0105] In S1004, the device control unit 102 instructs (notifies) the user to scan the color characteristic chart again. Specifically, the device control unit 102 displays a UI screen on the UI 104 to instruct (notify) the user to place the color characteristic chart printed by the target device 130 in a predetermined location, such as an ADF (not shown). The device control unit 102 displays, for example, a UI screen 511 shown in FIG. 5(b) on the UI 104.

[0106] In S1005, the device control unit 102 judges whether or not the characteristics of the color characteristic chart detected in S1003 are characteristics of a color characteristic chart for CMYK (characteristics of the CMYK color space). If the judgment result obtained in S1003 is that the characteristics of the color characteristic chart detected in S1003 are not characteristics of a color characteristic chart for CMYK (NO in S1005), the process proceeds to S1009. On the other hand, if the judgment result obtained in S1003 is that the characteristics of the color characteristic chart detected in S1003 are characteristics of a color characteristic chart for CMYK (YES in S1005), the process proceeds to S1006.

[0107] In S1006, the device control unit 102 acquires RGB signal values ​​of the color characteristic chart for creating a color matching profile for CMYK for each patch of the color characteristic chart from the scanned image data of the color characteristic chart acquired in S1001. Then, rearrangement of the data into an order required for creating a color matching profile for CMYK is also performed. In this embodiment, the rearrangement of the data is performed by associating each patch with a patch based on the characteristics of the patch arrangement of the scanned image data, but is not limited to this. Any method that can rearrange the order of the data may be used.

[0108] In S1007, the device control unit 102 converts the RGB signal values ​​acquired in S1006 into L * a * b * In this embodiment, the RGB signal values ​​are converted to L * a * b * In this embodiment, the conversion to an L value is performed as follows: * a * b * By performing an interpolation operation using a 3D-LUT (Look Up Table), a three-dimensional table that represents the relationship between the input RGB values ​​and the output L * a * b * This converts the color characteristic chart into a L value that indicates the color characteristic of the target device 130 when it is printed on the target device 130. * a* b * It is assumed that the 3D-LUT is stored in advance in the adjustment target device 100. The 3D-LUT is also called a three-dimensional lookup table.

[0109] In S1008, the device control unit 102 performs the L of the CMYK color characteristic chart converted in S1007. * a * b * value to convert the signal value in the CMYK color space to L * a * b * Color matching profile for CMYK to convert values ​​(CMYK to L * a * b * That is, the device control unit 102 creates a color conversion parameter for reproducing the color characteristics of the target device 130 by converting the color values ​​in the CMYK color space of the image data to be printed into L * a * b * A color matching profile is created to convert the signal values ​​of the CMYK patch into color values ​​in the color space. In this embodiment, the signal values ​​of the CMYK patch are expressed by 8 bits for each of C, M, Y, and K, and the signal value interval is 32. Therefore, the L of the output value corresponding to the interval of the input signal value is * a * b * The 4D-LUT is converted to match the format of the profile to be applied during color space conversion, resulting in a color matching profile (CMYK→L * a * b * The process of S1008 corresponds to the process of SQ223 in Fig. 2. 4D-LUT is also called a four-dimensional lookup table.

[0110] In S1009, the device control unit 102 judges whether or not the characteristics of the color characteristic chart detected in S1003 are characteristics of a color characteristic chart for RGB (characteristics of the RGB color space). If the judgment result obtained in S1003 is that the characteristics of the color characteristic chart detected in S1003 are not characteristics of a color characteristic chart for RGB (NO in S1009), the process proceeds to S1013. On the other hand, if the judgment result obtained in S1003 is that the characteristics of the color characteristic chart detected in S1003 are characteristics of a color characteristic chart for RGB (YES in S1009), the process proceeds to S1010.

[0111] In S1010, the device control unit 102 acquires RGB signal values ​​of the color characteristic chart for creating a color matching profile for RGB in units of patches of the color characteristic chart from the scanned image data of the color characteristic chart acquired in S1001. Then, rearrangement of data into an order necessary for creating a color matching profile for RGB is also performed. The rearrangement of data performed in S1010 is the same as that in S1006, and a description thereof will be omitted.

[0112] In S1011, the device control unit 102 converts the RGB signal values ​​acquired in S1010 into L * a * b * The conversion process executed in S1011 is the same as that in S1007, and therefore a description thereof will be omitted.

[0113] In S1012, the device control unit 102 calculates the L of the RGB color characteristic chart converted in S1011. * a * b * The signal value in the RGB color space is converted to L * a * b * Color matching profile for RGB to convert values ​​(sRGB to L * a * b * That is, the device control unit 102 creates a color conversion parameter for reproducing the color characteristics of the target device 130 by converting the color values ​​in the RGB color space of the image data to be printed into L * a * b* A color matching profile is created to convert the signal values ​​of the RGB patch into color values ​​in the color space. In this embodiment, the signal values ​​of the RGB patch are expressed by 8 bits for each of R, G, and B, and the signal value interval is 32. Therefore, the L of the output value corresponding to the interval of the input signal value is * a * b * The 3D-LUT is converted to match the format of the profile to be applied during color space conversion, resulting in a color matching profile (sRGB→L * a * b * ) is completed. The process of S1012 corresponds to the process performed in SQ224 of FIG.

[0114] In S1013, the device control unit 102 stores the color matching profile created in S1008 or S1012 in the storage unit 107 of the adjustment target device 100, and sets it in a state where the user can use it on the adjustment target device 100. The process of S1013 corresponds to the process performed in SQ225 of FIG.

[0115] This concludes the description of the flow of the color matching profile creation process according to this embodiment.

[0116] (Color characteristic chart feature detection processing) The details of the color characteristic chart feature detection process, which is the process of S1002 described above, will be described with reference to the drawings. FIG. 11 is a flowchart showing the flow of the color characteristic chart feature detection process. The process shown in FIG. 11 is executed by developing the program code stored in the storage unit 107 in the RAM 106 and controlling the device control unit 102 by the CPU 105. Note that data created during the process is temporarily stored in the RAM 106 or the storage unit 107. In the process shown in FIG. 11, based on the determination results of the total number of color characteristic charts and the number of patches on all pages of the color characteristic charts shown in Table 1, it is determined whether the input color space of the color characteristic chart is RGB or CMYK, or whether feature detection is impossible.

[0117] First, in S1101, the device control unit 102 detects area information indicating a patch area of ​​a color characteristic chart from a scanned image corresponding to one color characteristic chart among the scanned images obtained in the scanning process in S1001. The patch area detection process is a process for detecting the coordinate position of each patch by detecting area information of each of a plurality of patches from the entire area of ​​the scanned image corresponding to one color characteristic chart. Note that in the patch area detection process, the number of patches and the like are derived. Details of the patch area detection process will be described later with reference to the drawings.

[0118] In S1102, the device control unit 102 determines whether all scanned documents have been processed. That is, the device control unit 102 determines whether the patch area detection process of S1101 has been executed for all scanned images obtained in the scan process of S1001. If there are unprocessed scanned images and the determination result indicates that the patch area detection process has not been executed for all scanned images (NO in S1102), the process returns to S1101, and the process of S1101 is executed repeatedly. On the other hand, if there are no unprocessed scanned images and the determination result indicates that the patch area detection process has been executed for all scanned images (YES in S1102), the process proceeds to S1103.

[0119] In S1103, the device control unit 102 determines whether the scanned image obtained in the scan process of S1001 corresponds to the total number of color characteristic charts required to create a color matching profile for RGB. That is, the device control unit 102 determines whether the scanned image obtained in the scan process of S1001 corresponds to one color characteristic chart. If the determination result indicates that the scanned image corresponds to one color characteristic chart (YES in S1103), the process proceeds to S1104. On the other hand, if the determination result indicates that the scanned image does not correspond to one color characteristic chart (NO in S1103), the process proceeds to S1106.

[0120] In S1104, the device control unit 102 determines whether the number of patches on all pages derived in the process of S1101 is the number of patches on all pages necessary for creating a color matching profile for RGB. That is, the device control unit 102 determines whether the number of patches on all pages derived in the process of S1101 is 736. If the determination result indicates that the number of patches on all pages is 736 (YES in S1104), the process proceeds to S1105. On the other hand, if the determination result indicates that the number of patches on all pages is not 736 (NO in S1104), the process proceeds to S1107.

[0121] In S1105, the device control unit 102 determines that the input color space of the scanned image is RGB, and ends the feature detection process of the color characteristic chart shown in FIG.

[0122] In S1106, the device control unit 102 determines whether the scanned image obtained in the scan process of S1001 corresponds to the total number of color characteristic charts required to create a color matching profile for CMYK. That is, the device control unit 102 determines whether the scanned image obtained in the scan process of S1001 corresponds to eight color characteristic charts. If the determination result indicates that the scanned image corresponds to eight color characteristic charts (YES in S1106), the process proceeds to S1108. On the other hand, if the determination result indicates that the scanned image does not correspond to eight color characteristic charts (NO in S1106), the process proceeds to S1107.

[0123] In S1107, the device control unit 102 determines that feature detection of the scanned image has failed, and ends the feature detection process of the color characteristic chart shown in FIG.

[0124] In S1108, the device control unit 102 determines whether the number of patches on all pages derived in the process of S1101 is the number of patches on all pages necessary for creating a color matching profile for CMYK. That is, the device control unit 102 determines whether the number of patches on all pages derived in the process of S1101 is 6600. If the determination result indicates that the number of patches on all pages is 6600 (YES in S1108), the process proceeds to S1109. On the other hand, if the determination result indicates that the number of patches on all pages is not 6600 (NO in S1108), the process proceeds to S1107.

[0125] In S1109, the device control unit 102 determines that the input color space of the scanned image is CMYK, and ends the feature detection process of the color characteristic chart shown in FIG.

[0126] The above is an explanation of the flow of the feature detection process according to the present embodiment. In the feature detection process shown in FIG. 11, it is determined whether the input color space of the color characteristic chart is RGB or CMYK, or whether feature detection has failed, based on the determination results of both the total number of color characteristic charts and the number of patches on all pages of the color characteristic chart, but this is not limited to the above. The input color space of the color characteristic chart may be determined based on the determination result of the total number of color characteristic charts or the determination result of the number of patches on all pages of the color characteristic chart. In addition, the input color space of the color characteristic chart may be determined based on the determination result of items with different characteristics between the RGB and CMYK color characteristic charts, such as the items shown in Table 1 above.

[0127] (Color characteristic chart patch area detection process) The details of the color characteristic chart patch area detection process, which is the process of S1101 described above, will be described with reference to the drawings. Fig. 12 is a flowchart showing the flow of the color characteristic chart patch area detection process for detecting area information indicating the areas of each of a plurality of patches. The process shown in Fig. 12 is executed by developing the program code stored in the storage unit 107 in the RAM 106 and controlling the device control unit 102 by the CPU 105. Note that data created during the process is temporarily stored in the RAM 106 or the storage unit 107.

[0128] First, in S1201, the device control unit 102 performs filtering (filtering of scanned image data) on the scanned image obtained in the scanning process in S1001. The filtering is performed using a smoothing filter that eliminates halftone dots formed by the color characteristic chart printed by the device to be adjusted. By performing this filtering, multiple colorimetric values ​​for the same patch become the same value, making it possible to check the difference in each RGB value between adjacent patches without being affected by halftone dots.

[0129] In S1202, the device control unit 102 executes edge detection processing to detect the coordinates of the upper and lower ends that are the ends in the upper and lower directions in the color characteristic chart from the multiple colorimetric values ​​for each of the multiple patches using the scanned image data after the filter processing obtained in S1201. A method for detecting the coordinates of the edges that are the upper and lower ends of the color characteristic chart in this embodiment will be described with reference to the drawings. FIG. 13 is a diagram for explaining a method for detecting edge coordinates of the color characteristic chart. The color characteristic chart shown in FIG. 13 has the same configuration as the color characteristic chart shown in FIG. 3, and in FIG. 13, the x-axis direction is defined as the left-right direction, and the y-axis direction is defined as the up-down direction. In S1202, four coordinates y1, y2, y3, and y4 in FIG. 13 are detected as the coordinates of the upper and lower ends. When detecting the coordinates of the upper and lower ends, edge detection processing is executed in the y-axis direction. In the edge detection process of S1202, the difference between the signal value (each RGB value) of the target coordinate and the signal value (each RGB value) of the neighboring coordinate is calculated, and if the difference value obtained by this calculation is equal to or greater than a predetermined value, the target coordinate is detected as either the upper or lower end coordinate.

[0130] In S1203, the device control unit 102 executes edge detection processing to detect the coordinates of the left and right ends, which are the ends in the left and right directions in the color characteristic chart, from the multiple colorimetric values ​​for each of the multiple patches, using the scanned image data after the filter processing obtained in S1201. In S1203, four coordinates x1, x2, x3, and x4 in FIG. 13 are detected as the coordinates of the left and right ends. When detecting the coordinates of the left and right ends, edge detection processing is executed in the x-axis direction. In the edge detection processing in S1203, the difference between the signal value (each RGB value) of the target coordinate and the signal value (each RGB value) of the neighboring coordinate is calculated, and if the difference value obtained by this calculation is equal to or greater than a predetermined value, the target coordinate is detected as the coordinate of either the left or right end.

[0131] Here, the details of the method for detecting the coordinates of the left and right ends will be described with reference to the drawings. FIG. 14 is a diagram showing an example of detecting the coordinates of the left and right ends. As shown in FIG. 14, data 1400 for edge detection has an x ​​coordinate 1401, a y coordinate 1402, a signal value (RGB value) 1403, and a difference value 1404. The difference value 1404 is a value obtained by calculating the difference between the signal value 1403 at the corresponding coordinate and the signal value 1403 at the adjacent coordinate immediately before the corresponding coordinate. The signal value 1403 is 255 from 100 to 107 when the x coordinate 1401 is 108, and the signal value 1403 changes to 128 when the x coordinate 1401 is 108. Therefore, −127, which is the difference between 128 and 255, is calculated as the difference value 1404 at the x coordinate 1401 is 108.

[0132] In this embodiment, the coordinates of an edge are detected based on the difference between the signal value of a coordinate of interest and the signal value of its neighboring coordinates, but the present invention is not limited to this method and any method may be used as long as it is possible to detect the coordinates of an edge.

[0133] In S1204, the device control unit 102 executes a process of calculating the vertex coordinates of the color characteristic chart using the coordinates of the top, bottom, left and right ends obtained in the processes of S1202 and S1203. In S1204, four coordinates e1, e2, e3, and e4 in FIG. 13 are calculated as the coordinates of the vertices of the color characteristic chart. In the process of S1204, the intersection coordinates of a line passing through the coordinates y1 and y2 and a line passing through the coordinates x1 and x2 are calculated as the vertex coordinate e1 of the color characteristic chart. In a similar manner, the intersection coordinates of a line passing through the coordinates y3 and y4 and a line passing through the coordinates x1 and x2 are calculated as the vertex coordinate e2 of the color characteristic chart. The intersection coordinates of a line passing through the coordinates y1 and y2 and a line passing through the coordinates x3 and x4 are calculated as the vertex coordinate e3 of the color characteristic chart. The coordinates of the intersection between a line passing through the coordinates y3 and y4 and a line passing through the coordinates x3 and x4 are calculated as the vertex coordinates e4 of the color characteristic chart.

[0134] In S1205, the device control unit 102 extracts a signal value in the y-axis direction, which is the vertical direction, in the color characteristic chart area using the scanned image data after the filter process obtained in the process of S1201, and calculates a first derivative signal value using the extracted signal value. A calculation method of the first derivative signal value in this embodiment will be described with reference to the drawings. FIG. 15 is a diagram for explaining a method for detecting edge coordinates of a patch of the color characteristic chart. The color characteristic chart shown in FIG. 15 has the same configuration as the color characteristic chart shown in FIG. 3, and in FIG. 15, the x-axis direction is defined as the left-right direction, and the y-axis direction is defined as the up-down direction. The first derivative signal calculated in S1205 is a signal value calculated by first differentiating the extracted signal from top to bottom in the y direction as shown by the arrow 1501 in FIG. 15. Since the amount of change in the first derivative signal value increases near the edge of the patch, it is possible to detect the edge coordinates of the patch in the vertical direction by referring to the first derivative signal value obtained in the process of S1205.

[0135] In S1206, the device control unit 102 extracts a signal value in the x-axis direction, which is the left-right direction, within the color characteristic chart area using the scanned image data after the filter process obtained in the process of S1201, and calculates a first derivative signal value using the extracted signal value. The first derivative signal calculated in S1206 is a signal value calculated by first differentiating the extracted signal from left to right in the x-direction as indicated by an arrow 1502 in Fig. 15. Since the amount of change in the first derivative signal value increases near the edge of the patch, it is possible to detect the edge coordinates of the patch in the left-right direction by referring to the first derivative signal value obtained in the process of S1206.

[0136] In S1207, the device control unit 102 extracts a periodic component of the signal value using the first differential signal value obtained in the processes of S1205 and S1206. In the process of extracting the periodic component of the signal value in this embodiment, an autocorrelation analysis is performed on the first differential signal value obtained in the processes of S1205 and S1206 to calculate autocorrelation coefficient data. The autocorrelation coefficient data is calculated using an autocorrelation function R x (τ) is used to calculate.

[0137]

number

[0138] In equation (1), x represents the first differential signal value, N represents the number of first differential signal values, and τ represents the amount of deviation.

[0139] Next, the autocorrelation function R calculated using equation (1) x Using (τ), the autocorrelation coefficient data φ shown in the following equation (2) is obtained. x Calculate (τ).

[0140]

number

[0141] By using the autocorrelation analysis, it is possible to confirm the consistency of a signal with a signal shifted by an amount τ of the signal. In the autocorrelation coefficient data, the value τ at which the correlation coefficient is large indicates the periodicity of the signal. In other words, the autocorrelation coefficient data φ x By extracting the shift amount τ at which the correlation coefficient becomes large in (τ), it is possible to extract a periodic component including the size of the patch. Therefore, the autocorrelation coefficient data φ x Among (τ), extract the deviation amount τ that is the local maximum value that exceeds a predetermined threshold. x If (0) is 0, the autocorrelation coefficient data cannot be calculated, so the autocorrelation coefficient data φ x is set to 0. In this embodiment, the predetermined threshold is set to 0.3, which is a value at which it can be determined that there is a statistical correlation, but the present invention is not limited to this, and may be set to any predetermined value that can be set by the user, for example.

[0142] In S1208, the device control unit 102 calculates the size of the patch in the x-axis direction and the y-axis direction using the periodic components of the signal values ​​extracted in S1207. In this embodiment, the size of the patch is calculated as the size of the patch that includes the value obtained by multiplying the periodic components of the signal values ​​extracted in S1207 by an integer. This is because the autocorrelation coefficient data that is the periodic component increases by an integer multiple of the size of the patch.

[0143] Here, the process of calculating the size (length) of the patch will be described with reference to the drawings. FIG. 16 is a diagram showing an example of the first differential signal value and the autocorrelation coefficient data, and is a diagram explaining an example of the process of calculating the length of the patch. The calculation data 1600 of the length of the patch has an x ​​coordinate 1601, a y coordinate 1602, a signal value 1603, a first differential signal value 1604, a shift amount (τ) 1605, and an autocorrelation coefficient data φ(τ) 1606. The first differential signal value and the autocorrelation coefficient data φ(τ) have been described above, and their description will be omitted. When the shift amount (τ) 1605 is 8, 16, and 24, the autocorrelation coefficient data φ(τ) 1606 is 0.6, 0.5, and 0.4, respectively. When the shift amount (τ) 1605 is 1 to 7, 9 to 15, 17 to 23, and 25 to 31, the autocorrelation coefficient data φ(τ) 1606 is 0.

[0144] In S1209, the device control unit 102 calculates the number of patches using the vertex coordinates of the color characteristic chart obtained in the process of S1204 and the size of the patch in the x-axis direction and the y-axis direction obtained in the process of S1208. Specifically, first, the area of ​​the chart area is calculated using the vertex coordinates of the color characteristic chart (vertex coordinates e1, e2, e3, e4 in FIG. 13). Next, the area of ​​the patch is calculated using the size of the patch in the x-axis direction and the y-axis direction. The number of patches in the chart area is calculated by dividing the area of ​​the chart area by the area of ​​the patch.

[0145] In S1210, the device control unit 102 calculates the center coordinates of each patch using the vertex coordinates of the color characteristic chart obtained in the process of S1204 and the size of the patch obtained in the process of S1208.

[0146] This concludes the description of the flow of the patch area detection process for the color characteristic chart according to this embodiment. Note that the patch area detection process is not limited to the process shown in Fig. 12, and any method can be used as long as it can calculate the chart area of ​​the color characteristic chart, the number of patches, and the size of the patches.

[0147] The above is the flow of the color matching profile creation process by the adjustment target device (image processing device) 100 according to this embodiment.

[0148] As described above, according to this embodiment, the input color space of the color characteristic chart is specified (determined) based on the features of the color characteristic chart detected from the color measurement results of the color characteristic chart printed by the target device 130. This makes it possible to appropriately create a color matching profile according to the specified input color space.

[0149] Based on the measured values ​​obtained by measuring the color characteristics chart of the sRGB color space printed by the target device 130, a color matching profile (sRGB→L * a * b * ) can be created. In addition, a color matching profile (CMYK → L) can be created based on the measured values ​​obtained by printing a color characteristic chart in the CMYK color space. * a * b * ) can be created. By applying the created color matching profile to image data input in the CMYK color space, it becomes possible to print images that do not become dull.

[0150] [Embodiment 2] In this embodiment, a mode will be described in which the input color space of a color characteristic chart is specified by detecting the characteristics of the color characteristic chart based on a patch arrangement pattern of the color characteristic chart. Note that the patch arrangement pattern is also called a patch arrangement pattern.

[0151] The following describes this embodiment in terms of the differences from the above-described first embodiment.

[0152] Details of the color characteristic chart feature detection process according to this embodiment will be described with reference to the drawings. Fig. 17 is a flowchart showing the flow of the color characteristic chart feature detection process according to this embodiment. The process shown in Fig. 17 is executed by developing the program code stored in the storage unit 107 in the RAM 106 and controlling the device control unit 102 by the CPU 105. Note that data created during the process is temporarily stored in the RAM 106 or the storage unit 107.

[0153] First, in S1701, the device control unit 102 executes a process of detecting a patch area corresponding to the patch area of ​​a color characteristic chart for a scan image corresponding to one of the color characteristic charts among the scan images obtained in the scan process of S1001. Details of the patch area detection process are similar to the process of S1101 in the first embodiment, and therefore a description thereof will be omitted. Note that in the patch area detection process, the central coordinates of each patch and the like are derived.

[0154] In S1702, the device control unit 102 obtains the signal value (RGB value) of each patch of the color characteristic chart from the scanned image, using the central coordinates of each patch obtained in the process of S1701.

[0155] In S1703, the device control unit 102 calculates the hue of each patch using the signal value obtained in the process of S1702. In the hue calculation process in this embodiment, first, as in S1007, the RGB value, which is the input signal value, is converted into L * a * b * Convert it to a value, a * b * Divide the plane into four quadrants, the first quadrant, the second quadrant, the third quadrant, and the fourth quadrant, and calculate which quadrant it belongs to. * a * b * In color space, a * b * Since a is a chromaticity that indicates hue and saturation, * b * Using this, the color values ​​of each patch can be classified into four quadrants.

[0156] In S1704, the device control unit 102 calls up the patch arrangement pattern information of the RGB color characteristic chart stored in the storage unit 107. Note that the patch arrangement pattern information of the RGB color characteristic chart is used to determine whether the scanned image data is a color characteristic chart for RGB.

[0157] In S1705, the device control unit 102 executes page determination of the scanned image using the patch arrangement pattern of the RGB color characteristic chart. Specifically, the device control unit 102 compares, for each patch, the quadrant determined based on the patch arrangement pattern information of the RGB color characteristic chart called up in S1704 with the quadrant calculated in S1703. If the number of patches in the same quadrant is equal to or greater than a predetermined threshold, the device control unit 102 determines that the scanned image is a color characteristic chart for RGB. On the other hand, if the number of patches in the same quadrant is less than the predetermined threshold, the device control unit 102 determines that the scanned image is not a color characteristic chart for RGB.

[0158] Here, the determination process of the RGB color characteristic chart in S1705 will be specifically described. Table 4 shows the L * a * b * This is a table showing an example of comparing values ​​and quadrants on a patch-by-patch basis. * a * b * The patch count is then classified into quadrants based on the patch value, the number of patches in the same quadrant is counted, and the count value is compared with a threshold value to check whether the target scanned image corresponds to the patch arrangement pattern of the color characteristic chart for RGB. This threshold value is a value used to determine that the arrangement patterns are the same. The threshold value is, for example, a value that is half the total number of patches, and when this threshold value is exceeded, it is determined that the scanned image of the color characteristic chart and the called-up color characteristic chart for RGB have the same arrangement pattern. This is because the color values ​​of the color characteristic chart reproduced on the target device, including the profile and color settings, change, the color measurement accuracy is affected by the scanner's in-plane unevenness, etc., and a* b * This is to take into consideration variations in classification, such as when the quadrant changes due to the value being close to 0. If the array patterns are different, the number of matching quadrants will decrease, making it possible to distinguish the array patterns. Also, patch array patterns for the RGB color characteristic chart corresponding to when the reading orientation of the RGB color characteristic chart is changed by 90 degrees or 180 degrees may be prepared and readable in the processing of S1704 described above. By preparing patch array patterns for the RGB color characteristic chart corresponding to when the reading orientation is changed in this way, it becomes possible to also accommodate changes in the orientation of the RGB color characteristic chart to be scanned.

[0159] In the process of determining whether the color characteristic chart is for RGB according to this embodiment, the number of patches in the same quadrant is counted, and if the count value is equal to or greater than 368, which is half of the total number of patches, it is determined that the color characteristic chart is for RGB. In the example of Table 4, with regard to the quadrants of the scanned image and the array pattern, the second patch is always the same in the second quadrant, and the Nth patch is always the same in the first quadrant, so the second and Nth patches are counted as the number of patches in the same quadrant.

[0160] [Table 4]

[0161] In S1706, the device control unit 102 determines whether the scanned image data is a patch arrangement pattern corresponding to the color characteristic chart for RGB. Specifically, if the determination result obtained in the process of S1705 is the color characteristic chart for RGB (YES in S1706), the process proceeds to S1707. On the other hand, if the determination result obtained in the process of S1705 is not the color characteristic chart for RGB (NO in S1706), the process proceeds to S1711.

[0162] In S1707, the device control unit 102 sets the read flag of the corresponding page of the RGB color characteristic chart determined in S1705 to "already read." The flag is a variable expressed in 1 bit, and the read flag in this embodiment is true (already read) when the corresponding page has been read, and false when it has not been read. This makes it possible to check the read flag of the RGB or CMYK color characteristic chart, and determine that all of the color characteristic charts for creating a color matching profile for RGB or CMYK have been read if all of the read flags have been read.

[0163] In S1708, the device control unit 102 checks whether the read flags of the RGB color characteristic chart set in S1707 have been read for all pages. If the read flags of all pages of the RGB color characteristic chart have been set to read (YES in S1708), the process proceeds to S1709. On the other hand, if the read flags of all pages of the RGB color characteristic chart have not been set to read (NO in S1708), the process proceeds to S1711.

[0164] In S1709, the device control unit 102 determines that the input color space of the color characteristic chart corresponding to the scanned image is RGB.

[0165] In S1710, the device control unit 102 determines whether or not all of the scan image data obtained in the process of S1001 has been processed. If the determination result indicates that all of the scan image data has not been processed (NO in S1710), the process returns to S1701, and the series of processes from S1701 onwards are executed for the unprocessed scan images. Therefore, the series of processes from S1701 onwards are repeated until the processing is executed for all pages. On the other hand, if the determination result indicates that all of the scan image data has been processed (YES in S1710), the process proceeds to S1717.

[0166] In S1711, the device control unit 102 calls up patch arrangement pattern information of the CMYK color characteristic chart stored in the storage unit 107. Note that the patch arrangement pattern information of the CMYK color characteristic chart is used to determine whether the scanned image data is a CMYK color characteristic chart.

[0167] In S1712, the device control unit 102 executes page determination of the scanned image using the patch arrangement pattern of the CMYK color characteristic chart. Specifically, the device control unit 102 compares the quadrant calculated in S1703 with the quadrant determined based on the patch arrangement pattern information of the CMYK color characteristic chart called in S1711 for each patch. Then, if the number of patches in the same quadrant is equal to or greater than a predetermined threshold, the device control unit 102 determines that the scanned image is a CMYK color characteristic chart. On the other hand, if the number of patches in the same quadrant is less than a predetermined threshold, the device control unit 102 determines that the scanned image is not a CMYK color characteristic chart. The method of calculating the quadrant is the same as that of the RGB color characteristic chart in S1705, so the description will be omitted. In the determination process of the CMYK color characteristic chart according to this embodiment, the number of patches in the same quadrant is counted, and if the count value is equal to or greater than 412, which is half of the total number of patches, it is determined that the scanned image is a CMYK color characteristic chart.

[0168] In S1713, the device control unit 102 determines whether the scanned image data is a patch arrangement pattern corresponding to a CMYK color characteristic chart. Specifically, if the determination result obtained in the process of S1712 is a CMYK color characteristic chart (YES in S1713), the process proceeds to S1714. On the other hand, if the determination result obtained in the process of S1712 is not a CMYK color characteristic chart (NO in S1713), the process proceeds to S1710.

[0169] In S1714, the device control unit 102 sets the read flag of the corresponding page of the CMYK color characteristic chart determined in S1712 to "already read." The read flag of the CMYK color characteristic chart is the same as the read flag of the RGB color characteristic chart, and a description thereof will be omitted.

[0170] In S1715, the device control unit 102 checks whether the read flags of the CMYK color characteristic charts set in S1714 have been read for all pages. If the read flags of all pages of the CMYK color characteristic charts have been set to read (YES in S1715), the process proceeds to S1716. On the other hand, if the read flags of all pages of the CMYK color characteristic charts have not been set to read (NO in S1715), the process proceeds to S1710.

[0171] In S1716, the device control unit 102 determines that the input color space of the color characteristic chart corresponding to the scanned image is CMYK.

[0172] In S1717, the device control unit 102 checks whether the input color space determination result of S1709 or S1716 has been obtained. If the input color space determination result of S1709 or S1716 has been obtained (YES in S1717), the color matching profile creation process according to the feature detection result becomes possible, and the feature detection process of the color characteristic chart shown in Fig. 17 ends. On the other hand, if the input color space determination result of S1709 or S1716 has not been obtained (NO in S1717), the process proceeds to S1718.

[0173] In S1718, the device control unit 102 determines that feature detection has failed, and ends the feature detection process for the color characteristic chart shown in FIG.

[0174] This concludes the description of the flow of the feature detection process by the image processing device (adjustment target device) 100 according to this embodiment.

[0175] As described above, according to this embodiment, a feature detection process is performed using a patch arrangement pattern of a color characteristic chart, and the input color space of the color characteristic chart is specified (discriminated) based on the feature detection result. This makes it possible to appropriately create a color matching profile according to the specified input color space.

[0176] Regarding the feature detection process, we have explained a method of identifying (determining) the input color space of the color characteristic chart by comparing the hue quadrant with the patch arrangement pattern, but any method that can identify the input color space of the color characteristic chart can be used.

[0177] In the above, the process proceeds to S1711 when the read flags of all pages of the RGB color characteristic chart are not set to "already read" (NO in S1708). However, the present invention is not limited to this. For example, the process may proceed to S1710 when the read flags of all pages of the RGB color characteristic chart are not set to "already read" (NO in S1708).

[0178] [Embodiment 3] In this embodiment, a mode will be described in which the input color space of a color characteristic chart is specified by detecting the characteristics of the color characteristic chart based on a discrimination code formed outside the patch area of ​​the color characteristic chart. The discrimination code is also called an identification code for identifying the input color space.

[0179] The following describes this embodiment in terms of the differences from the above-described first embodiment.

[0180] An example of the configuration of a color characteristic chart according to this embodiment will be described with reference to the drawings. FIG. 18 is a diagram showing an example of the configuration of a color characteristic chart printed to check the color characteristics of a target device. As shown in FIG. 18, a color characteristic chart 1801 has a discrimination character string 1802 and a patch area 1803. The discrimination character string 1802 includes a specific character string representing a discrimination code for discriminating (classifying) whether the input color space of the color characteristic chart is RGB or CMYK and the page number of the color characteristic chart. By reading the discrimination character string 1802 of the color characteristic chart 1801, the input color space of the color characteristic chart and the page number of the color characteristic chart can be discriminated (classified).

[0181] For example, in the case of a color characteristic chart in which the input color space is RGB, the discrimination character string 1802 includes "RGB" as the discrimination character string 1802, and in the case of a color characteristic chart in which the input color space is CMYK, the discrimination character string 1802 includes "CMYK" as the discrimination character string 1802. In the case of a color characteristic chart having multiple pages, such as a CMYK color characteristic chart, the discrimination character string 1802 may include, for example, "N page (N is an integer)" to distinguish the page number.

[0182] As a method for identifying a character string, for example, a method may be used in which image data is subjected to OCR (Optical Character Recognition), which is a character recognition process, and a character string that matches the identifying character string is detected from among the recognized character strings.

[0183] Next, the details of the color characteristic chart feature detection process according to this embodiment will be described with reference to the drawings. Fig. 19 is a flowchart showing the flow of the color characteristic chart feature detection process according to this embodiment. The process shown in Fig. 19 is executed by developing the program code stored in the storage unit 107 in the RAM 106 and controlling the device control unit 102 by the CPU 105. Note that data created during the process is temporarily stored in the RAM 106 or the storage unit 107.

[0184] First, in S1901, the device control unit 102 executes a process of detecting a patch area corresponding to the patch area of ​​the color characteristic chart for a scanned image corresponding to one of the color characteristic charts among the scanned images obtained in the scanning process of S1001. Details of the patch area detection process are similar to the process of S1101 in the first embodiment, and therefore will not be described.

[0185] In S1902, the device control unit 102 executes a process of detecting a discrimination code from the scanned image (image data) corresponding to one sheet of the color characteristic chart obtained in the process of S1001. In the discrimination code detection process, a process of detecting a discrimination code from a character string recognized by executing OCR on the scanned image is performed.

[0186] In S1903, the device control unit 102 determines whether or not a discrimination code corresponding to RGB has been detected. Specifically, the device control unit 102 determines whether or not a discrimination code of any of the RGB pages is included in the character string recognized in the process of S1902. If the determination result indicates that a discrimination code of any of the RGB pages is included (YES in S1903), the process proceeds to S1904. On the other hand, if the determination result indicates that a discrimination code of any of the RGB pages is not included (NO in S1903), the process proceeds to S1907.

[0187] In S1904, the device control unit 102 sets the read flag of the corresponding page of the RGB color characteristic chart determined in S1903 to "already read." The read flag is the same as in the second embodiment described above, and a description thereof will be omitted.

[0188] In S1905, the device control unit 102 checks whether the read flags of the RGB color characteristic chart set in S1904 have been read for all pages. If the read flags of all pages of the RGB color characteristic chart have been set to read (YES in S1905), the process proceeds to S1906. On the other hand, if the read flags of all pages of the RGB color characteristic chart have not been set to read (NO in S1905), the process proceeds to S1911.

[0189] In S1906, the device control unit 102 determines that the input color space of the color characteristic chart corresponding to the scanned image is RGB.

[0190] In S1907, the device control unit 102 determines whether or not a discrimination code corresponding to CMYK has been detected. Specifically, the device control unit 102 determines whether or not a discrimination code of any of the CMYK pages is included in the character string recognized in the process of S1902. If the determination result indicates that a discrimination code of any of the CMYK pages is included (YES in S1907), the process proceeds to S1908. On the other hand, if the determination result indicates that a discrimination code of any of the CMYK pages is not included (NO in S1907), the process proceeds to S1911.

[0191] In S1908, the device control unit 102 sets the read flag of the corresponding page of the color characteristic chart for CMYK determined in S1907 to "already read."

[0192] In S1909, the device control unit 102 checks whether the read flag for the CMYK color characteristic chart set in S1908 has been read for all pages. If all pages of the CMYK color characteristic chart have been set as having been read (YES in S1909), the process proceeds to S1910. On the other hand, if all pages of the CMYK color characteristic chart have not been set as having been read (NO in S1909), the process proceeds to S1911.

[0193] In S1910, the device control unit 102 determines that the input color space of the color characteristic chart corresponding to the scanned image is CMYK.

[0194] In S1911, the device control unit 102 determines whether or not all of the scanned image data obtained in the process of S1001 has been processed. If the determination result indicates that all of the image data has not been processed (NO in S1911), the process returns to S1901, and the series of processes from S1901 onwards are executed on the unprocessed scanned images. Therefore, the series of processes from S1901 onwards are repeated until the processing has been executed on all pages. On the other hand, if the determination result indicates that all of the scanned image data has been processed (YES in S1911), the process proceeds to S1912.

[0195] In S1912, the device control unit 102 checks whether the input color space determination result of S1906 or S1910 has been obtained. If the input color space determination result of S1906 or S1910 has been obtained (YES in S1912), the color matching profile creation process according to the feature detection result becomes possible, and the feature detection process of the color characteristic chart shown in Fig. 19 ends. On the other hand, if the input color space determination result of S1906 or S1910 has not been obtained (NO in S1912), the process proceeds to S1913.

[0196] In S1913, the device control unit 102 determines that feature detection has failed, and ends the feature detection process for the color characteristic chart shown in FIG.

[0197] This concludes the description of the flow of the feature detection process by the image processing device (adjustment target device) 100 according to this embodiment.

[0198] As described above, according to this embodiment, a feature detection process is performed using the discrimination code of the color characteristic chart, and the input color space of the color characteristic chart is identified (discriminated) based on the feature detection result. This makes it possible to appropriately create a color matching profile according to the identified input color space.

[0199] Although the discrimination code has been described as a specific character string, the present invention is not limited to this. For example, information on the input color space of the color characteristic chart may be formed on the color characteristic chart as code information such as a barcode or QR code (registered trademark), and the information formed on the color characteristic chart may be readable. In this case, the adjustment target device 100 and the target device 130 are provided with a function for recognizing code information, and the process of S1902 is capable of recognizing the code information formed on the color characteristic chart from the scanned image obtained in the process of S1001.

[0200] [Other embodiments] Although the method of calculating the size of a patch in a color characteristic chart using periodicity or autocorrelation analysis has been described above, the present invention is not limited to this, and any method may be used as long as it can calculate the size of a patch. For example, a method may be used in which an edge detection filter such as a first derivative filter or a second derivative filter is applied to the scanned image, and the size of a patch is calculated using the distance between detected edges.

[0201] The present disclosure can also be realized by a process in which a program for implementing one or more functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. It can also be realized by a circuit (e.g., ASIC) that implements one or more functions.

Claims

1. an acquisition unit that reads the color of a printed matter on which a predetermined density pattern is formed and acquires color characteristics of a first image forming apparatus that has output the printed matter; A detection means for detecting a feature related to the printed matter from the printed matter; a specifying unit that specifies an input color space corresponding to the printed matter output by the first image forming apparatus based on the characteristics of the printed matter detected by the detecting unit; a creating means for creating color conversion parameters that correspond to the input color space specified by the specifying means, based on the color characteristics of the first image forming device acquired by the acquiring means, and that reproduce the color characteristics of the first image forming device in a second image forming device; 13. An image processing device comprising:

2. the predetermined density pattern is made up of a plurality of patches, each patch corresponding to a color of a particular density; the detection means detects area information indicating an area of ​​each of the plurality of patches from a plurality of colorimetric values ​​for each of the plurality of patches, and acquires features related to the patch using the detected area information for each of the plurality of patches; The specifying means specifies an input color space corresponding to the printed matter based on at least one of the characteristics of the printed matter and the characteristics of the patch.

2. The image processing device according to claim 1,

3. The detection means detects at least one of the number of the patches formed in the row direction on one printed sheet, the number of the patches formed in the column direction on one printed sheet, the total number of the patches formed on one printed sheet, and the total number of the patches formed on all pages of the printed sheet as the feature of the patch.

3. The image processing device according to claim 2.

4. the predetermined density pattern is made up of a plurality of patches, each patch corresponding to a color of a particular density; the detection means detects an arrangement pattern of the plurality of patches from a plurality of colorimetric values ​​of each of the plurality of patches; 2. The image processing device according to claim 1, wherein the identifying means identifies an input color space corresponding to the printed matter based on an arrangement pattern of the plurality of patches detected by the detecting means and an arrangement pattern of patches corresponding to an input color space.

5. an identification code for identifying an input color space is formed on a printed matter outputted by the first image forming device; the detection means detects the identification code by reading a printout output by the first image forming device; The specifying means specifies an input color space corresponding to the printed matter based on the identification code detected by the detecting means.

2. The image processing device according to claim 1,

6. The information providing device further includes a providing means for providing information to a user, When the specifying means specifies an input color space corresponding to the printed matter, The providing means provides the user with a UI screen for receiving an instruction to create the color conversion parameters corresponding to the input color space identified by the identifying means.

6. The image processing device according to claim 1, wherein the image processing device further comprises:

7. When the specifying means specifies the CMYK color space as the input color space corresponding to the printed matter, The providing means converts color values ​​in the CMYK color space of the image data to be printed into L * a * b * A UI screen is provided to the user for receiving an instruction to create a four-dimensional lookup table for converting the color values ​​of the color space as the color conversion parameters.

7. The image processing device according to claim 6,

8. When an instruction to create the four-dimensional lookup table is received on the UI screen provided by the providing means, 8. The image processing apparatus according to claim 7, wherein said creating means creates said four-dimensional lookup table as said color conversion parameters.

9. When the specifying means specifies an RGB color space as an input color space corresponding to the printed matter, The providing means converts color values ​​in the RGB color space of the image data to be printed into L * a * b * A UI screen is provided to the user for receiving an instruction to create a three-dimensional lookup table for converting the color values ​​of the color space as the color conversion parameters.

7. The image processing device according to claim 6,

10. When an instruction to create the three-dimensional lookup table is received on the UI screen provided by the providing means, 10. The image processing apparatus according to claim 9, wherein said creating means creates said three-dimensional lookup table as said color conversion parameters.

11. an acquisition step of reading the color of a printed matter on which a predetermined density pattern is formed, and acquiring color characteristics of a first image forming apparatus which has output the printed matter; a detection step of detecting a feature related to the printed matter from the printed matter; a specifying step of specifying an input color space corresponding to the printed matter output by the first image forming apparatus based on the characteristics of the printed matter detected in the detecting step; a creating step of creating color conversion parameters that correspond to the input color space identified in the identifying step and reproduce the color characteristics of the first image forming device in a second image forming device, based on the color characteristics of the first image forming device acquired in the acquiring step; 13. An image processing method comprising:

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

Images