JP2006186846A - Generation of adjustment data by scanning colors in multiple areas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an input value by an image input device and a colorimetric value by a colorimeter so as to obtain a more accurate colorimetric value when obtaining a colorimetric value of a color of a target portion using the image input device. A technique for performing the association is provided.
First, a colorimetric value is obtained by reading a color of a reference chart including a single color region with a colorimeter. Then, the color of the reference chart is read by the image input device to obtain an input value. Thereafter, conversion data for storing the colorimetric value and the input value in association with each other is generated. When the reference chart is read by the image input device, the color of the first portion included in the single color area is read to obtain the first input value. In addition, a second portion that is included in the monochrome region and is different from the first portion is read by the image input device to obtain a second input value. Then, when the first and second input values are closer than a predetermined reference, an input value representing the color characteristics of the monochrome region is obtained based on the first and second input values. On the other hand, if both are not closer than the predetermined standard, a warning is issued.
[Selection] Figure 9

Description

  The present invention relates to a technique for obtaining a colorimetric value of a color of a predetermined target part, and more particularly to a technique for obtaining a colorimetric value of a color of a target part using an image input device such as a scanner.

  The adjustment of the printing characteristics of the printing apparatus includes, for example, printing the data of the sample chart with the printing apparatus to be adjusted, and comparing the colorimetric value obtained by measuring the color of the printed image with a preset desired colorimetric value. (For example, Patent Document 1). Color measurement of a printed image is generally performed using a colorimeter.

JP 2000-209450 A JP 2002-204370 A JP 2002-262106 A

  In the adjustment of the printing characteristics of the printing apparatus, instead of using the colorimetric value obtained by the colorimeter, an input value obtained by inputting a print image using a relatively inexpensive image input apparatus such as a scanner can be used. The printing characteristics can be adjusted economically. However, since the image input device is not originally a device for color measurement, when the image input device is used for adjusting the printing characteristics of the printing device, the input value by the image input device is associated with the color measurement value by the colorimeter. It is desirable that Such association can be realized, for example, by associating an input value obtained by reading the same object painted in a single color with an image input device and a colorimeter and a colorimetric value.

  However, in an image input device that can read a color of a wide area to some extent, even if the color of a single-color object is read, an input value that is generated depends on which part of the image reading unit of the image input device has read it. May be different. For example, among the many light receiving elements provided in the image input device, when the light receiving portions of some of the light receiving elements are dirty or the performance is degraded, the input value generated depends on which light receiving element is used for reading. May be different. In such a case, if the association is performed based on the input value generated in that portion, it is not possible to accurately adjust the print characteristics based on the association.

  Such a problem is not limited to the adjustment of the printing characteristics of the printing apparatus, but is a common problem when the input value from the image input apparatus is used instead of the colorimetric value from the colorimeter.

  The present invention has been made to solve the above-described conventional problems, and when obtaining a colorimetric value of a color of a target portion using an image input device, a more accurate colorimetric value can be obtained. Another object of the present invention is to provide a technique for associating an input value by an image input device with a colorimetric value by a colorimeter.

  In order to solve at least a part of the above problems, the present invention provides the following when generating conversion data that stores an input value generated by an image input device and a colorimetric value generated by a colorimeter in association with each other. Perform the process. That is, first, (a) a color of a reference chart including a single color area having a single color is read by a colorimeter to obtain a colorimetric value representing the color characteristics of the single color area. Also, (b) the color of the reference chart is read by the image input device, and an input value representing the color characteristics of the single color region is obtained. Then, (c) conversion data for storing the colorimetric value and the input value in association with each other is generated.

  When the input value is obtained by reading the color of the reference chart with the image input device, the following processing is performed. That is, first, (b1) the color of the first portion included in the single color area is read by the image input device, and the first input value representing the color characteristics of the first portion is obtained. Also, (b2) a second portion that is included in the single color area and is different from the first portion is read by the image input device, and a second input value representing the color characteristics of the second portion is obtained. And (b3) an input representing the color characteristics of the monochromatic region based on at least one of the first and second input values when the first and second input values are closer than a predetermined reference. Get the value. On the other hand, (b4) a warning is issued when the first and second input values are not closer than a predetermined reference.

  According to such an aspect, after confirming the performance of the image input device based on the input values of the two portions, the input value by the image input device and the colorimetric value by the colorimeter are associated with each other. be able to. Therefore, when obtaining the colorimetric value of the color of the target portion using the image input device, the input value by the image input device and the colorimetric value by the colorimeter are obtained so that a more accurate colorimetric value can be obtained. Association can be performed.

  Note that the image input device is preferably capable of simultaneously reading the colors of a plurality of target portions and generating an input value representing the color characteristics of each target portion. The colorimeter is preferably capable of reading the color of the target part and generating a colorimetric value representing the color characteristic of the target part with higher accuracy than the image input unit.

  When the color of the reference chart is read by the colorimeter to obtain a colorimetric value representing the color characteristics of the single color area, the color of the third part included in at least one of the first and second parts Is preferably read with a colorimeter to obtain a colorimetric value corresponding to a single color region. According to such an aspect, the colorimetric value is generated based on the third part, and the input value is generated in consideration of the part including the third part. For this reason, conversion data can be generated based on the colorimetric value and the input value obtained based on a more approximate target.

  In addition, when the monochromatic area is a rectangular area, the first and second points when the two points that internally divide one diagonal line of the rectangle into 1: 2: 1 are defined as the first and second points, respectively. The portion 2 is preferably configured as follows. That is, the first portion preferably includes the first point. And it is preferable that a 2nd part contains a 2nd point. According to such an aspect, the first and second portions can be set by securing a predetermined area for each of the first and second portions and taking a predetermined distance from the outer edge of the monochromatic region. it can.

  Note that the first and second portions are regions inside the positions parallel to the first side of the rectangle from the positions corresponding to 1/8 of the length of the first side from both ends of the first side. It is preferable that the direction parallel to the second side that is a rectangular side and perpendicular to the first side is 1/8 of the length of the second side from both ends of the second side. It is preferable that it is an area | region inside a position. With such an aspect, it is possible to obtain an input value in which the measurement error due to the outer edge of the monochromatic region is less likely to be reflected in the input value for the first and second portions.

  Moreover, it is preferable that the first and second portions are regions separated from each other in the single color region. With such an aspect, it is possible to obtain input values that are not easily influenced by each other for the first and second portions. As a result, the conversion data can be generated by confirming the performance of the image input apparatus more precisely.

  Note that it is also preferable to generate adjustment data for correcting the printing characteristics of the printing apparatus using the image input apparatus in the following manner. That is, first, (d) conversion data is generated by any one of the methods described above. On the other hand, (e) when a color designation value for designating a predetermined series of colors is given, color reproduction target data for storing colorimetric values representing the characteristics of the colors to be reproduced by the printing apparatus is prepared.

  Then, (f) based on the sample color designation value that is a color designation value that designates the sample color included in the predetermined series, the printing device prints the adjustment single color area having a single color. After that, (g) the adjustment monochromatic area is imaged by the image input device, and an object input value that is an input value representing the color characteristic of the adjustment monochromatic area is obtained. Then, (h) using the converted data, the target input value is converted into a target colorimetric value that is a colorimetric value representing the color characteristics of the adjustment monochrome region. By performing such processing, a target colorimetric value that does not reflect the bias in performance of the image input device can be obtained for the adjustment monochrome region.

  Thereafter, (i) using the color reproduction target data, the target colorimetric value is converted into an ideal designated value that is a color designated value corresponding to the adjustment monochrome region. Then, (j) adjustment data is generated based on the sample color designation value and the ideal designation value.

  According to such an aspect, even if adjustment data is generated using an image input device that may include a predetermined performance bias, adjustment data that allows the printing apparatus to execute printing with characteristics close to ideal characteristics. Can be generated.

The colorimetric value is preferably the value of L ^* in the L ^* a ^* b ^* color system. According to such an aspect, the characteristics of the printed patch can be evaluated by the lightness (value of L ^* ) which is an absolute reference, and accurate adjustment data can be generated.

  Further, the predetermined series of colors is preferably an achromatic color having different brightness. When printing the adjustment monochrome area, it is preferable to print the adjustment monochrome area using black ink in the printing apparatus based on the sample color designation value.

  The input value can be a gradation value of a red, green, or blue color component.

  It is also preferable that the adjustment data is generated by the above method, and the adjustment data is stored in the storage unit of the printing apparatus to manufacture the printing apparatus.

  The present invention can be implemented in various modes. For example, an image processing method and system, an image input value conversion method and system, a print adjustment amount setting method and system, and the functions of these methods or systems The present invention can be realized in the form of a computer program for realizing, a recording medium recording the computer program, a data signal including the computer program and embodied in a carrier wave, and the like.

Next, embodiments of the present invention will be described in the following order based on examples.
A. Summary of embodiment:
B. Example:
B-1. Image processing system configuration:
B-2. Print adjustment amount setting process:
C. Variations:

A. Summary of embodiment:
For a plurality of patches having different lightness values, an image input value (R value) of a red color component obtained by reading with an image input device, and an image colorimetric value (L ^* value) obtained by measuring with a colorimeter , LUT files are created. First, the printer 500 prints a plurality of reference charts BC-1 to BC-N including patches having different designated densities using black ink. The upper left area A1 in each patch included in each of the reference charts BC-1 to BC-N is imaged by the scanner 400 (see FIG. 9), and an image input value R1 of the red color component for the patch j is obtained. Thus, the original input value file BIF1 is generated. On the other hand, the lower right area A2 of the patch is imaged, and similarly, an image input value R2 of a red color component is obtained, and a comparison input value file BIF2 is generated.

  It is determined whether the difference between the image input values R1 and R2 of the red color component for the same patch included in the original input value file BIF1 and the comparison input value file BIF2 is larger than a predetermined value Thr. If it is larger than the predetermined value Thr, a warning is issued and the creation of the LUT file is stopped. When the difference between R1 and R2 is equal to or smaller than the predetermined value Thr, an LUT file is generated based on the original input value file BIF1.

On the other hand, an ideal relationship IR, which is data defining the relationship between the gradation value G of black ink and the ideal lightness L ^* that the printer should reproduce when the gradation value G is given, is created in advance. (Refer to the lower left of FIG. 16).

  When setting the adjustment amount, first, the sample chart SC including the patch j reproduced based on the sample gradation value GSj is printed using the black ink by the printer 500t that is the target of the print adjustment amount setting process. (Refer to the upper left of FIG. 16). The patch j is imaged by the scanner 400, an image input value (R value) of the red color component for the patch j is obtained, and a sample input value file SIF is generated (see the right side of FIG. 16).

Then, based on the LUT file described above, the sample conversion file SCF is generated by replacing the red image input value (R value) with the image colorimetric value (L ^* value). Further, an ideal gradation value GIj representing which gradation value is reproduced when the patch j having the lightness L ^* is reproduced in an ideal printer is based on the above-described ideal relation IR. Ask. Then, an adjustment amount Bj corresponding to the patch j for the printer 500t is obtained by (sample gradation value GSj) / (ideal gradation value GIj). When printing is performed, when a gradation value of a pixel is input, the gradation value is replaced with a value multiplied by Bj, and printing is executed. As a result, when the gradation value GIj is input, the printer 500t reproduces the lightness color having the lightness L ^{* as} in the ideal relation IR.

B. First embodiment:
B-1. Image processing system configuration:
FIG. 1 is an explanatory diagram schematically showing the configuration of an image processing system as a first embodiment of the present invention. The image processing system 10 according to the present embodiment can be used for a print adjustment amount setting process to be described later for setting an adjustment amount B for adjusting the print characteristics of a printer. The image processing system 10 includes a computer 100, a colorimeter 300, and a scanner 400. Further, the image processing system 10 may include a printer 500.

  The computer 100 includes a CPU 110, an internal storage device 200 such as a ROM and a RAM, a display unit 120 such as a display, an operation unit 130 such as a keyboard and a mouse, an external storage device 140 such as a hard disk drive, a current date, A timer 150 for outputting time and an interface unit (I / F unit) 160 are provided. Each component in the computer 100 is connected to each other via a bus 170.

  The internal storage device 200 includes an LUT generation unit 210, a print adjustment amount setting unit 220, an elapsed day determination unit 230, a color measurement processing unit 240, an imaging processing unit 250, a print processing unit 260, and an imaging inspection unit. 270. Each of these units is a computer program that functions as each unit. The LUT generation unit 210 includes an LUT generation date addition unit 212, and the print adjustment amount setting unit 220 includes an input value conversion unit 222 and an ideal relationship IR.

  The color measurement processing unit 240 is a color measurement driver that controls the color measurement device 300, and includes a color measurement date addition unit 242. The imaging processing unit 250 is a scanner driver that controls the scanner 400, and includes a date input / addition unit 252 and an input value determination unit 254. The print processing unit 260 is a printer driver that controls the printer 500. The imaging inspection unit 270 is application software and determines whether the performance of the scanner 400 is normal. If it is determined to be normal, inspection data is generated, and if it is determined to be abnormal, a warning is displayed on the display 120 connected to the computer 100. The interface unit 160 includes a plurality of input / output terminals, and performs data communication with external devices such as the colorimeter 300, the scanner 400, and the printer 500.

The colorimeter 300 is a device that performs colorimetry on an image and obtains a colorimetric value. In this embodiment, the colorimetric values L ^* , a ^* , and b ^{* in} the L ^* a ^* b ^* color space. Is output. Note that the colorimeter may be any device that can measure a certain color and output the brightness of the color as a colorimetric value. In addition, it is preferable that the colorimeter has a smaller change in performance over time than the image input device.

  The scanner 400 is an apparatus that captures an image and obtains an input value of the image. In this embodiment, the scanner 400 outputs three input values of an R value, a G value, and a B value. The scanner 400 captures a target image by scanning light receiving elements arranged in a line. In this specification, “imaging” refers to reading the colors of a plurality of target portions at the same time and generating an input value representing the color characteristics of each target portion. The printer 500 is an ink jet printer, and in this embodiment, an image is printed using four colors of inks of C (cyan), M (magenta), Y (yellow), and K (black).

B-2. Print adjustment amount setting process:
FIG. 2 is a flowchart showing the flow of print adjustment amount setting processing by the image processing system of this embodiment. Here, the print adjustment amount setting process is a process of setting an adjustment amount B for adjusting the print characteristics of the printer to be desirable characteristics. In this embodiment, when an image is printed based on certain image data, an adjustment amount B as a coefficient to be multiplied by the gradation value of the image data is set in order to make the print result desirable. The adjustment amount B is desirably set for each combination of ink nozzles used for printing, usable dot diameters, and printing modes (resolutions).

  In step S100 (see FIG. 2), the user prepares the reference chart BC. The reference chart BC is obtained by printing a plurality of patches by a printer 500 of the same type as the printer that is the target of the print adjustment amount setting process.

  In this embodiment, the reference chart BC is updated every predetermined number of days in consideration of the change in the color characteristics of the reference chart BC and the change in the input characteristics of the scanner 400. In this embodiment, it is assumed that the preparation of the reference chart BC in step S100 is performed once every 90 days.

  FIG. 3 is a flowchart showing a flow of processing for preparing the reference chart BC. FIG. 4 is an explanatory diagram showing data generated or used in the process of preparing the reference chart BC and the process of preparing the LUT file in the print adjustment amount setting process. In step S110 of FIG. 3, it is determined whether or not there is an existing reference chart BC. If there is no existing reference chart BC, the process proceeds to step S140, and the reference chart BC is produced (printed). On the other hand, when there is an existing reference chart BC, the process proceeds to step S120.

  In step S120, it is determined whether or not the existing reference chart BC is within the expiration date, that is, whether or not a predetermined number of days have passed since the date of preparation of the reference chart BC. The predetermined number of days is set to 90 days, for example. When it is determined that the existing reference chart BC has exceeded the expiration date, the process proceeds to step S140, and a new reference chart BC is produced. On the other hand, when it is determined that the existing reference chart BC is within the expiration date, the process proceeds to step S130 to prepare the existing reference chart BC.

  FIG. 5 is an explanatory diagram schematically showing the contents of the reference chart BC. The reference chart BC used in this embodiment is composed of N sheets (N is an integer of 2 or more). In addition, a total of 24 patches of 6 rows × 4 columns are printed on each sheet of the reference chart BC. In the following description, each sheet of the reference chart BC is represented by using a sheet number i (i is an integer of 1 to N), and patches in each sheet are patch numbers j (j is 1 to 24). (Integer). A sheet number i is displayed on the upper right of each sheet of the reference chart BC. Also, the patch number j of the upper left patch of each sheet is set to 1, the patch number j of the patch adjacent to the right of the patch of patch number 1 is set to 2, and the patch number j is assigned in the same manner. The patch number j is 24. These patches correspond to a “monochromatic area” in the claims.

  In each sheet of the reference chart BC, the number of rows of patches corresponds to the number of inks used by the printer 500 used for printing the reference chart BC. Since the printer 500 of this embodiment uses four colors of inks of C, M, Y, and K, the number of rows of patches is four. The patch in the first row from the left is printed using a cyan nozzle, the patch in the second row is printed using a magenta nozzle, the patch in the third row is printed using a yellow nozzle, The fourth row of patches is printed using a black nozzle. However, in this embodiment, all patches are printed using black ink. That is, for example, the patch in the first row is printed with black ink using a nozzle that is originally for cyan.

  In this way, by printing patches using black ink, it is possible to reproduce a wide range of brightness, and to easily detect subtle deviations in brightness when scanned with a colorimeter or scanner. Can be printed. In addition, when the printing apparatus that prints the patch includes the photo black ink whose printing result is glossy and the matte black ink whose printing result is not glossy, the matte black ink whose printing result is not glossy More preferably, is used. In addition, since black ink can be manufactured inexpensively, the cost at the time of implementing this embodiment can be reduced.

  In each sheet of the reference chart BC, the number of patch lines corresponds to the type of dot diameter and the number of print modes of the printer 500 used for printing the reference chart BC. The printer 500 according to the present embodiment performs printing using three types of dot diameters of large dots, medium dots, and small dots, and print mode 1 (high resolution mode) and print mode 2 (low resolution mode). ) And two print modes. Therefore, the number of patch lines is six. The patches on the first to third lines from the top are printed using the printing mode 1, and the patches on the fourth to sixth lines are printed using the printing mode 2. The patches on the first and fourth lines are printed using large dots. Similarly, the second and fifth lines use medium dots, and the third and sixth lines use small dots. Used and printed.

  Each sheet of the reference chart BC is printed based on image data having different gradation values G for patches having the same patch number j (patches printed at the same position in each sheet). That is, if the gradation value G of the image data used for printing the patch with the patch number j on the i-th sheet is expressed as “Gij”, the N gradation values from G1j to GNj are all different values. It has become. Therefore, the reference chart BC includes patches printed based on image data having N types of gradation values for each print mode and dot diameter for each ink color nozzle.

  In this embodiment, for each patch number j, the image data used for printing the patch on the first sheet has the largest gradation value G (that is, the patch is dark black), and N sheets The gradation value G of the image data is decreased toward the eye sheet (that is, the patch is light black (gray)). Note that the printing gradation expression in the printer 500 is performed by adjusting the number of dots applied per unit area. In this embodiment, the larger the gradation value D of the image data used for printing the patch, the larger the unit area. The number of dots per dot is increased. Further, the gradation value G of the image data used for printing does not need to be the same between the 24 patches in one sheet, and may be different from each other.

  Furthermore, the date of manufacture (print date) of the reference chart BC is displayed on each sheet of the reference chart BC. In the present embodiment, the N sheets of the reference chart BC are printed on the same day, and the same date is displayed on each sheet.

  FIG. 4 shows the prepared reference chart BC. Although FIG. 4 shows that the reference chart BC is printed by the printer 500 connected to the computer 100 of the image processing system 10, the printer 500 used for printing the reference chart BC is the image processing system 10. It is not necessary to be connected to.

  After completing the preparation of the reference chart BC in step S100 (see FIG. 2), in step S300, the LUT file is prepared. The LUT file is for associating an image input value from the scanner 400 with an image colorimetric value from the colorimeter 300. The contents of the LUT file will be described later.

  In this embodiment, the LUT file is updated every predetermined number of days in consideration of changes in input characteristics of the scanner 400 and the like. That is, the preparation of the LUT file in step S300 is performed once every 30 days in principle. FIG. 6 is a flowchart showing a flow of LUT file preparation processing. In step S310, it is determined whether there is an existing LUT file. If there is no existing LUT file, the process advances to step S400 to generate an LUT file. On the other hand, if there is an existing LUT file, the process proceeds to step S320.

  In step S320, it is determined whether or not the existing LUT file is within the expiration date, that is, whether or not a predetermined number of days have elapsed since the LUT file generation date. For example, the predetermined number of days is set to 30 days. If it is determined that the existing LUT file has exceeded the expiration date, the process proceeds to step S400, and a new LUT file is generated. On the other hand, when it is determined that the existing LUT file is within the expiration date, the process proceeds to step S330 to prepare the existing LUT file.

FIG. 7 is a flowchart showing a flow of processing for generating an LUT file in step S400 of FIG. In step S410, the colorimetric processing unit 240 (see FIG. 1) controls the colorimeter 300 to measure the color of the reference chart BC, and generates a colorimetric value file MF. FIG. 4 shows how the color of the reference chart BC is measured to generate a colorimetric value file MF. FIG. 8 is an explanatory diagram showing an example of the colorimetric value file MF. The colorimetric processing unit 240 measures 24 patches for each of the N sheets of the reference chart BC, and represents the lightness in the L ^* a ^* b ^* color space as an image colorimetric value for each patch. Get the value of ^* . For example, the first and second lines of the colorimetric value file MF shown in FIG. 8 indicate L ^* values of 24 patches in the sheet having the sheet number i of 1 in the reference chart BC.

  In step S420 (FIG. 7), the color measurement date adding unit 242 (see FIG. 1) in the color measurement processing unit 240 adds the color measurement date to the color measurement value file MF. The color measurement date adding unit 242 refers to the current date output from the timer 150 (see FIG. 1) during or after the color measurement processing by the color measurement processing unit 240, for example, the color measurement date as text data Is added to the colorimetric value file MF. The color measurement value file MF shown in FIG. 8 shows a state in which the color measurement date is added.

  In step S430 (FIG. 7), the imaging processing unit 250 (see FIG. 1) images the reference chart BC, and generates an original input value file BIF1 and a comparison input value file BIF2. FIG. 4 shows a state in which the reference chart BC is imaged and the original input value file BIF1 and the comparison input value file BIF2 are generated.

  FIG. 9 is a diagram illustrating a method of generating the original input value file BIF1 and the comparison input value file BIF2 by imaging the reference chart BC. The imaging processing unit 250 (see FIG. 1) uses the scanner 400 to image the reference chart BC-i, and the R value, G value, and B value of a large number of pixels corresponding to the area of the reference chart BC-i. Three input values are output.

  In the upper part of FIG. 9, a first area A1 indicated by a thick broken line is a predetermined area on the scanner 400 side. When the reference chart BC-i is correctly positioned on the image reading table of the scanner 400, the first area A1 is within the patch area with the patch number j = 1 among the patches of the reference chart BC-i. It is an included area. When the two points dividing the diagonal line D1 of the rectangular patch into 1: 2: 1 are defined as the first point p1 and the second point p2, respectively, the first region A1 is defined as the first point p1. including. FIG. 9 shows that the points p1 and p2 are on the intersection of straight lines that internally divide the two sides of the patch into 1: 2: 1.

  In the upper part of FIG. 9, the second area A2 indicated by a thick broken line is also an area determined in advance on the scanner 400 side, like the first area A1. This second area A2 is also an area included in the patch area of patch number j = 1 when the reference chart BC-i is correctly positioned on the image reading table of the scanner 400. The second area A2 includes a second point p2. The first and second regions A1 and A2 are regions that do not overlap each other.

  In the upper part of FIG. 9, a boundary B1 indicated by a fine broken line is a line that is 1/8 of the length L1 and L2 of each side from the outer contour of the patch of j = 1. When the reference chart BC is correctly positioned on the image reading table of the scanner 400, the first and second areas A1 and A2 are located inside the patch with respect to the boundary B1.

  The first and second regions A1, A2 are rectangular. The lengths of the sides Sa11 and Sa21 of the first and second regions A1 and A2 are ¼ of the length L1 of the side S1 of the patch parallel to them. The lengths of the other sides Sa12, Sa22 of the first and second regions A1, A2 are ¼ of the length L2 of the side S2 of the patch parallel to them.

  In step S430 in FIG. 7, the imaging processing unit 250 obtains the average of the R values of the pixels included in the first area A1, and sets this as the first input value R1 of the patch with the patch number j = 1. Then, the imaging processing unit 250 obtains an average of the R values of the pixels included in the second area A2, and uses the average as the second input value R2 of the patch with the patch number j = 1.

  The lower part of FIG. 9 schematically shows a graph of an R value obtained by reading a patch with j = 1 along the line CC in the upper part of FIG. Here, it is assumed that there is no variation in the performance of each light receiving element included in the scanner 400. As shown by the broken line graph G0 in the figure, the R value is originally recorded at a constant value for the portion where the patch is printed, and the graph should draw a rectangle. However, at the boundary B1 between the portion where the patch is printed and the portion where the patch is not printed, the read value of the R value is disturbed as shown by the solid line graph G1 in the figure. For this reason, it is difficult to obtain an R value that accurately reflects the color characteristics of the patch in the vicinity of the boundary B1.

  However, in this embodiment, the input value of the patch is determined based on the R value read in the areas A1 and A2 further inside the line B1 that is 1/8 from the outer contour of the patch of j = 1. Therefore, an R value that accurately reflects the color characteristics of the patch can be obtained. Further, since the read values of the R values in the predetermined areas A1 and A2 are averaged to obtain the input value of the patch, the influence of the error can be further reduced.

  Regions similar to the first and second regions corresponding to the patch of j = 1 are determined corresponding to the patches of j = 2 to 24. The imaging processing unit 250 obtains a first input value R1 and a second input value R2 for each patch with j = 1 to 24. Further, the imaging processing unit 250 obtains the 24 sets of the first input value R1 and the second input value R2 for the N reference charts BC. In this embodiment, the R value is used as the image input value of the reference chart BC. However, for example, other image input values such as a G value and a B value can be used.

  FIG. 10 is an explanatory diagram showing an example of the original input value file BIF1 and the comparison input value file BIF2. The imaging processing unit 250 generates the original input value file BIF1 from the first input value R1 for each patch of j = 1 to 24 of the N reference charts BC obtained as described above. For example, the first and second lines of the original input value file BIF1 shown in FIG. 10A indicate the input values R1 of 24 patches in the sheet having the sheet number i of 1 in the reference chart BC. Similarly, the imaging processing unit 250 generates a comparison input value file BIF2 from the second input values R2 for each patch j = 1 to 24 of the N reference charts BC obtained as described above (FIG. 10 (b)).

  After that, in step S435 of FIG. 7, the input value determination unit 254 (see FIG. 1) of the imaging processing unit 250 corresponds to the first and second input values R1, 1 corresponding to the original input value file BIF1 and the comparison input value file BIF2. Compare the value of R2. That is, the magnitude of the difference between the input values R1 and R2 generated by reading the first and second regions A1 and A2 included in the same patch of the same reference chart BC-i is determined. If the difference ΔR between the input values R1 and R2 is less than or equal to the predetermined value Thr for all patches of j = 1 to 24 of all the reference charts BC of i = 1 to N, the process proceeds to step S440. If there is a patch in which the difference ΔR between the input values R1 and R2 exceeds the predetermined value Thr, a warning “Scanner measurement value error” is displayed as indicated by a broken line in the display 120 in the upper part of FIG. To end the process.

  In this embodiment, the scanner 400 generates an input value using a plurality of light receiving elements. Each chart is placed on the reading surface of the scanner 400 and the color is read. Therefore, if the light receiving element is dirty or the reading surface of the scanner 400 is dirty, an accurate input cannot be made. However, as described above, the color is read at two places in the patch, and if the difference between the two input values is large, a warning is issued to prevent the occurrence of the LUT file based on the abnormal input value. it can.

  FIG. 11 is an explanatory diagram showing an example of the reference input value file BIF. In step S440 (FIG. 7), the date input / addition unit 252 (see FIG. 1) in the imaging processing unit 250 adds the creation date of the reference chart BC to the original input value file BIF1 to generate the reference input value file BIF. To do. The date input / addition unit 252 has an OCR function for optically reading printed characters, reads the reference chart BC production date printed on each sheet of the reference chart BC, and stores it in the original input value file BIF1. Append. The input value of the original input value file BIF1 corresponds to the “input value representing the color characteristics of the monochrome region” in the claims. In FIG. 11, the added reference chart BC creation date is shown at the bottom of the reference input value file BIF.

  In addition, the position where each color is read by the colorimeter 300 in step S410 in FIG. 7 is a predetermined position in the first area A1. For example, the colorimetric value can be obtained by reading the color of the region A3 having a diameter of about 3 mm including the point p1 with the colorimeter 300. By adopting such an aspect, an accurate LUT is obtained based on the reference input value file BIF and the colorimetric value file MF generated by reading the same object (the area A1 and the area A3 included in the area A1). A file can be generated.

  In step S450 (FIG. 7), the elapsed days determination unit 230 (see FIG. 1) determines the elapsed days from the colorimetric date. The determination of the number of days elapsed from the color measurement date is performed to determine whether or not the color measurement value file MF used for generating the LUT file is correct. As described above, since the LUT file is updated every 30 days, for example, the LUT file generation process shown in FIG. 7 is also repeatedly executed every 30 days. Therefore, there is a possibility that the old colorimetric value file MF generated in the previous LUT file generation process is erroneously used in the new LUT file generation process. In this embodiment, in order to prevent misuse of the old colorimetric value file MF, the number of days elapsed from the colorimetric date is determined.

  For example, specifically, the elapsed days from the color measurement date is determined by the elapsed date determination unit 230 from the current date output from the timer 150 (see FIG. 1) and the color measurement date included in the color measurement value file MF. (See FIG. 8), and by determining whether the number of days elapsed from the colorimetric date to the present is within 5 days. That is, if the number of days elapsed from the color measurement date to the present is within 5 days, it is determined that the color measurement value file MF is correct. If the number of elapsed days is 6 days or more, the color measurement value file MF is old. It is determined to be a thing. Note that the determination threshold may be less than the LUT file update cycle, and the threshold may be set shorter or longer. For example, if all the steps of the LUT file generation process shown in FIG. 7 are necessarily performed on the same day, the threshold value may be set to one day.

  In the determination of the number of days elapsed from the colorimetric date in step S450 (FIG. 7), when it is determined that the number of days elapsed is 6 days or more, the process is terminated and the colorimetric value file MF is confirmed. On the other hand, when it is determined that the number of elapsed days is within 5 days, the process proceeds to step S460.

  In step S460 (FIG. 7), the elapsed days determination unit 230 (see FIG. 1) determines the elapsed days from the reference chart BC production date. To determine the number of days elapsed from the date of creation of the reference chart BC, whether or not the reference input value file BIF used to generate the LUT file is correct, and consequently the reference chart BC used to generate the reference input value file BIF is correct. This is to determine whether or not there has been. As described above, since the reference chart BC is updated, for example, every 90 days, the old reference chart BC may be erroneously used when the reference input value file BIF is generated. In this embodiment, in order to prevent misuse of the old reference chart BC, the number of days elapsed from the reference chart BC production date is determined.

  For example, specifically, the elapsed days determination from the reference chart BC creation date is performed by the elapsed day determination unit 230 including the current date output from the timer 150 (see FIG. 1) and the reference included in the reference input value file BIF. This is done by comparing the chart BC production date and determining whether or not the number of days elapsed from the reference chart BC production date to the present date is within 95 days. That is, if the number of days elapsed from the creation date of the reference chart BC to the present is within 95 days, it is determined that the reference chart BC used to generate the reference input value file BIF is correct, and the elapsed days are 96 days or more. If so, it is determined that the reference chart BC used to generate the reference input value file BIF is old. Note that the determination threshold may be equal to or longer than the update period of the reference chart BC and less than twice the update period of the reference chart BC, and may be set shorter or longer. I do not care. For example, the threshold value may be set to 90 days.

  If it is determined in step S460 (FIG. 7) that the number of days elapsed since the reference chart BC creation date is 96 days or more, the process is terminated and the reference input value file BIF is confirmed. On the other hand, when it is determined that the number of elapsed days is within 95 days, the process proceeds to step S470.

  In step S470 (FIG. 7), the LUT generation unit 210 (see FIG. 1) generates an LUT file using the colorimetric value file MF and the reference input value file BIF. FIG. 4 shows how the LUT file is generated using the colorimetric value file MF and the reference input value file BIF. FIG. 12 is an explanatory diagram showing an example of an LUT file. FIG. 12A shows details of the contents of the LUT file. As shown in FIG. 12A, the LUT file includes 24 LUTs (LUT-1 to LUT-24) corresponding to the 24 patches in each sheet in the reference chart BC. In the following description, the LUT corresponding to the patch with the patch number j is represented as LUT-j.

LUT-j is an image colorimetric value (L ^* value) in the colorimetric value file MF (see FIG. 8) and an image input value (R value) in the reference input value file BIF (see FIG. 8) for the patch with patch number j. 11), the number of sheets corresponding to the number of sheets of the reference chart BC is included. For example, in the LUT-1 corresponding to the patch whose patch number j is 1 shown at the top of FIG. 12A, the L ^* value of the patch whose patch number j is 1 in the colorimetric value file MF, The R value of the patch whose patch number j is 1 in the reference input value file BIF is associated with each sheet number i.

Here, each sheet in the reference chart BC is printed based on image data having different N types of gradation values G for patches having the same patch number j. Therefore, for example, the LUT-1 corresponding to the patch whose patch number j is 1 is the correspondence between the L ^* value and the R value for N types of patches printed based on image data having N types of gradation values. It represents. FIG. 12B shows this correspondence using a graph. As described above, the LUT-j associates the image input value at the predetermined position of the scanner 400 (the patch position of the patch number j) with the image colorimetric value of the colorimeter 300. As shown in FIG. 12B, when the LUT is actually used, the correspondence specified by the N patches is interpolated using, for example, linear interpolation.

  In step S480 (FIG. 7), the LUT generation date adding unit 212 (see FIG. 1) adds the generation date of the LUT file to the LUT file. The LUT generation date adding unit 212 refers to the current date output from the timer 150 (see FIG. 1) during or after generation of the LUT file by the LUT generation unit 210, for example, the LUT file generation date as text data, Append to LUT file. The LUT file shown in FIG. 12A shows a state in which the LUT file generation date is added. This LUT file corresponds to “conversion data” in the claims.

  After the LUT file preparation in step S300 (see FIG. 2) is completed, the scanner 400 (see FIG. 1) is inspected in step S360. In principle, the inspection of the scanner 400 in step S360 is performed once every 24 hours. Note that the scanner 400 may not be checked on Saturday and Sunday. The relationship between the scanner inspection interval T1, the LUT file update interval T2, and the reference chart BC update interval T3 is preferably T1 <T2 <T3.

FIG. 13 is a flowchart showing the flow of the inspection process of the scanner 400. FIG. 14 is a diagram illustrating data created when the scanner 400 is inspected. In step S362 of FIG. 13, the colorimetric processing unit 240 (see FIG. 1) controls the colorimeter 300 to measure the color of the check chart CC and generates a colorimetric value file CMF (see the upper left of FIG. 14). Here, it is assumed that the inspection chart CC is the reference chart BC-M having the center sheet number among the N reference charts BC (see FIG. 4). The colorimetric processing unit 240 measures the 24 patches of the inspection chart CC and acquires the value of L ^* as the image colorimetric value for each patch.

  In step S364, the imaging processing unit 250 (see FIG. 1) images the inspection chart CC and generates an inspection input value file CIF1 (see the upper right in FIG. 14). The imaging processing unit 250 images the inspection chart CC and acquires an R value that represents the gradation value of the R component as an image input value at the positions of 24 patches in the sheet. In this embodiment, the R value is used as the image input value of the inspection chart CC. However, other image input values such as gradation values of other color components, for example, G value and B value may be used. Is possible.

  In step S364, the imaging processing unit 250 stores the time when the inspection chart CC is captured in the inspection input value file CIF1. The imaging processing unit 250 refers to the current time output from the timer 150 (see FIG. 1) during or after the imaging process, and stores, for example, the imaging time as text data in the inspection input value file CIF1. The stored colorimetric time includes date information. Hereinafter, the imaging time of the inspection chart CC is referred to as “scanner inspection time”. The inspection input value file CIF1 shown in FIG. 14 shows a state where the scanner inspection time is added.

In step S366, the input value conversion unit 222 (see FIG. 1) of the print adjustment amount setting unit 220 converts the image input value (R value) in the inspection input value file CIF1 into an L ^* value using the LUT file. The inspection input value file CIF2 is generated (see the lower right in FIG. 14). The contents of the process of converting the R value into the L ^* value are the same as when the sample conversion file SCF is generated from the sample input value file SIF using the LUT file. This process will be described later.

In step S368, the imaging inspection unit 270 (see FIG. 1) compares the L ^* values of the corresponding patches in the colorimetric value file CMF and the inspection input value file CIF2, and the difference ΔL ^* between them is within a predetermined value Th. It is determined whether or not. For example, the predetermined value Th can be a value 1 of L ^* in the L ^* a ^* b ^* color system. However, the predetermined value Th may be any value between 0.8 and 1.2. However, the predetermined value Th is more preferably a value within the range of 0.9 to 1.1. Of L ^* value of each patch of inspection input value file CIF2, when the magnitude of the deviation from the L ^* value of the corresponding colorimetric value file CMF there is more than the predetermined value Th, the imaging inspection unit 270 In step S370, as shown in the lower part of FIG. 14, a warning such as “the scanner measurement value is abnormal” is displayed on the display 120 of the computer 100 (see FIG. 1), and the process ends.

  When a warning is displayed on the display 120 of the computer 100, the user checks the dirt on the reading surface of the scanner 400, checks whether the lamp is burned out, etc. The cause of the abnormality can be confirmed and removed. In addition, it is possible to confirm whether the inspection chart CC is dirty. If no abnormality is found, the LUT file is recreated (see step S300 in FIG. 2). Therefore, with such an aspect, it is possible to prevent a situation in which the adjustment amount B of the printer 500t is set in step S500 (see FIG. 2) as it is when the scanner may generate an abnormal input value. .

  On the other hand, when the determination result is Yes in step S368, the imaging inspection unit 270 displays “scanner inspection end” or the like on the display 120, and reads the information on the scanner inspection time in the inspection input value file CIF2. Then, it is stored as inspection data in the external storage device 140 (see the lower left in FIG. 14). That is, the inspection data is data including the scanner inspection time. When the inspection data already exists in the external storage device 140, the imaging inspection unit 270 updates the inspection data. As a result, the scanner inspection time is updated. As described above, since the inspection of the scanner 400 is performed once in 24 hours, the inspection data and the scanner inspection time are updated in 23 to 25 hours if the inspection of the scanner 400 is properly performed. Thereafter, the process proceeds to step S500 in FIG.

  After the inspection of the scanner 400 is completed in step S360 (see FIG. 2), the print adjustment amount setting unit 220 (see FIG. 1) sets the adjustment amount B in step S500. The adjustment amount B is set for each printer on the production line.

  FIG. 15 is a flowchart showing the flow of the adjustment amount B setting process. FIG. 16 is an explanatory diagram showing data generated or used when the adjustment amount B is set. In step S505 in FIG. 15, the elapsed day determination unit 230 (see FIG. 1) reads the scanner inspection time from the inspection data in the external storage device 140, and determines the elapsed time from the scanner inspection time. As described above, the periodic inspection of the scanner 400 should be performed, for example, every 24 hours. In this embodiment, it is possible to prevent a situation in which the adjustment amount of the printer 500t is set using the scanner 400 in a state where the regular inspection of the scanner 400 is not performed within a predetermined time from the current time. Therefore, in step S505, the elapsed time from the scanner inspection time is determined.

  Specifically, the elapsed day determination unit 230 compares the current time output from the timer 150 (see FIG. 1) with the scanner inspection time included in the inspection data in step 505, and compares the current time output from the scanner inspection time with the current time. It is determined whether the elapsed time until is within 30 hours. If the elapsed time from the scanner inspection time to the present time is less than 30 hours, it is determined that the scanner 400 has been properly subjected to periodic inspection. If the elapsed time is 30 hours or more, the scanner 400 properly performs periodic inspection. It is determined that it has not been received. In addition, it is preferable that the threshold value for the determination is equal to or more than the time interval for performing the periodic inspection and less than twice the time interval for performing the periodic inspection. However, the threshold value may be set shorter or longer. For example, if the periodic inspection of the scanner 400 is always performed within 25 hours, the threshold value may be set to 25 hours.

  If it is determined in step S505 that the elapsed time is 30 hours or more, the print adjustment amount setting unit 220 displays a warning such as “cancel adjustment amount setting” on the display 120 of the computer 100 in step S507. The process is terminated (see the upper right in FIG. 16). On the other hand, when it is determined that the elapsed time is less than 30 hours, the display 120 displays “adjustment amount setting start” or the like (see the upper left in FIG. 16), and proceeds to step S510.

  In step S510, the user prints the sample chart SC using the printer 500t that is the target of the print adjustment amount setting process. FIG. 16 shows how the sample chart SC is printed using the printer 500t. Here, the sample chart SC is a chart having the same pattern as the reference chart BC shown in FIG. 5, and 24 patches having different ink nozzles, dot diameters, and printing modes used for printing were printed using black ink. Is. However, the sample chart SC is composed of only one sheet. Each patch of the sample chart SC corresponds to an “adjustment monochrome region” in the claims.

  Here, if the gradation value of the image data used for printing the patch with the patch number j in the sample chart SC is expressed as “sample gradation value GSj”, the sample gradation value GSj is expressed by the following equation (1). Is set to satisfy. As described above, G1j is the gradation value of the image data used for printing the patch with the patch number j in the first sheet of the reference chart BC, and GNj is in the Nth sheet of the reference chart BC. Is the gradation value of the image data used for printing the patch with patch number j.

  G1j <GSj <GNj (1)

  This sample gradation value GSj corresponds to a “sample color designation value” in the claims.

  In step S520 (FIG. 15), the imaging processing unit 250 (see FIG. 1) images the sample chart SC and generates a sample input value file SIF. FIG. 16 shows a state in which the sample chart SC is imaged and a sample input value file SIF is generated. The imaging processing unit 250 acquires an R value that represents the gradation value of the R component as an image input value at the position of 24 patches in the sample chart SC. In the generated sample input value file SIF, the R value at the patch position of each patch number in the sample chart SC is represented in the same manner as the reference input value file BIF shown in FIG. This R value corresponds to the “target input value” in the claims.

  In step S530 (FIG. 15), the elapsed day determination unit 230 (see FIG. 1) determines the elapsed days from the LUT file generation date. The determination of the number of days elapsed from the LUT file generation date is performed in order to determine whether or not the LUT file used for the adjustment amount B setting process is correct. As described above, since the LUT file is generated every 30 days, the old LUT file generated before may be erroneously used in the adjustment amount B setting process. In this embodiment, in order to prevent misuse of this old LUT file, the number of days elapsed from the LUT file generation date is determined.

  For example, specifically, the elapsed days determination from the LUT file generation date is performed by the elapsed day determination unit 230 including the current date output from the timer 150 (see FIG. 1) and the LUT file generation date included in the LUT file ( Compared with FIG. 12), it is determined by determining whether or not the number of days elapsed from the LUT file generation date to the present is within 35 days. That is, if the number of days elapsed from the LUT file generation date to the present is within 35 days, the LUT file is determined to be correct, and if the number of days elapsed is 36 days or more, the LUT file is determined to be old. Is done. Note that the determination threshold may be longer than the LUT file update cycle and less than twice the LUT file update cycle, and may be set shorter or longer. . For example, the threshold value may be set to 30 days.

  In the determination of the number of days elapsed from the LUT file generation date in step S530 in FIG. 15, when it is determined that the number of days elapsed is 36 days or more, the process is terminated and the LUT file is confirmed. On the other hand, when it is determined that the number of elapsed days is within 35 days, the process proceeds to step S540.

In step S540 (FIG. 15), the input value conversion unit 222 (see FIG. 1) of the print adjustment amount setting unit 220 uses the LUT file to convert the image input value (R value) in the sample input value file SIF to L ^*. A sample conversion file SCF converted into values is generated. FIG. 16 shows how the sample conversion file SCF is generated from the sample input value file SIF using the LUT file.

Specifically, the input value conversion unit 222 converts the R value of the patch with the patch number in the sample input value file SIF into an L ^* value using the LUT corresponding to each patch number. For example, the R value of the patch whose patch number j is 1 in the sample input value file SIF is converted to L ^* using the LUT-1 (FIG. 12B) corresponding to the patch number 1. By using the 24 LUTs (LUT-1 to LUT-24) included in the LUT file, all the R values of the 24 patches in the sample input value file SIF can be converted into L ^* values. In the generated sample conversion file SCF, the L ^* values in the patches of the respective patch numbers in the sample chart SC are represented as in the colorimetric value file MF shown in FIG. This L ^* value corresponds to the “target colorimetric value” in the claims.

In step S550 (FIG. 15), the print adjustment amount setting unit 220 (see FIG. 1) calculates an ideal gradation value GI for each L ^* value in the sample conversion file SCF using the ideal relationship IR. FIG. 17 is an explanatory diagram schematically showing the ideal relationship IR. As shown in FIG. 17, the ideal relationship IR indicates a relationship between a gradation value G of image data used for printing a patch and a desired L ^* value of the patch when the patch is printed using black ink. Defined. In other words, if the relationship between the tone value G and the L ^* value of the patch is on the curve of the ideal relationship IR, it is a desirable print characteristic. This ideal relationship IR corresponds to “color reproduction target data” in the claims.

Further, L ^* is the ideal grayscale value GI for a value, which means the gradation value G on ideal relationship IR curve corresponding to a L ^* value. In other words, when a patch of lightness L ^* is to be printed on an ideal printer, the gradation value to be instructed to the ideal printer is determined by the ideal relationship IR curve and the ideal gradation determined by the L ^* value. The value GI. Accordingly, the calculation of the ideal gradation value GI for each L ^* value in the sample conversion file SCF (see FIG. 16) means that the brightness of the print result is the value in the sample conversion file SCF when an ideal printer is used. This means that each gradation value G of the image data that becomes the L ^* value is calculated. Note that the ideal gradation value GI for the L ^* value of the patch with the patch number j in the sample conversion file SCF is represented as an ideal gradation value GIj. The ideal gradation value GIj corresponds to an “ideal designated value” in the claims.

  In step S560 (FIG. 15), the print adjustment amount setting unit 220 (see FIG. 1) sets the adjustment amount B. The adjustment amount B is a coefficient for multiplying the gradation value of the image data used for printing so that a desired printing result can be obtained in the target printer 500t. The adjustment amount Bj corresponding to the patch with the patch number j in the sample conversion file SCF is calculated by the following equation (2).

  Adjustment amount Bj = (sample gradation value GSj) / (ideal gradation value GIj) (2)

Since the adjustment amount B is set corresponding to the L ^* value of each patch, a total of 24 adjustment amounts B (B1 to B24) are set. Each of the 24 adjustment amounts B corresponds to a combination of the ink nozzle, the dot diameter, and the printing mode used for printing the corresponding patch in the sample chart SC. The adjustment amount B set as described above is stored as adjustment amount data BF in a predetermined storage area of the target printer 500t.

When printing is performed using a combination of nozzles, dot diameters, and the like when printing the patch j, adjustment is performed by multiplying the gradation value of the pixel in the image data used for printing by the corresponding adjustment amount Bj. For example, when the gradation value GIj is designated for a certain pixel, the gradation value GIj is multiplied by the adjustment amount Bj and replaced with GSj. As a result, the printer 500t reproduces the color whose brightness is the L ^* value based on the replaced gradation value GSj. With respect to the relationship between the gradation value of the input image data and the printing result, a color having a lightness L ^* value is reproduced for a pixel for which the gradation value GIj is designated in the image data. Therefore, when the gradation value GIj is designated for a certain pixel, the printer 500t performs printing similar to an ideal printer.

  Note that, in the case where a gradation value other than the gradation value GIj is designated for the pixels in the image data, adjustment is similarly performed by multiplying the gradation value by the adjustment amount Bj. Based on the image data adjusted in this way, the printer 500t performs the subsequent printing process. As a result, the printer 500t can perform printing similar to an ideal printer.

  As described above, according to the image processing system 10 of the present embodiment, the association between the image input value by the scanner 400 and the image colorimetric value by the colorimeter 300 is executed by generating an LUT file. Can do. The adjustment value B can be set using the scanner 400 so that the printer 500t can perform printing similar to an ideal printer.

Further, in the image processing system 10 of the present embodiment, the inspection chart CC is imaged by the scanner 400 every predetermined period, for example, every 24 hours. Then, the gradation value of the color component scanner 400 generates a value of data obtained from (R value) (L ^* value) is the value of the data obtained by colorimetry at a colorimeter (L ^* value) relative to Then, it is determined whether it is within a predetermined range (see step S368 in FIG. 13). If the gradation value is outside the predetermined range, a warning is displayed on the display 120 of the computer 100. For this reason, it is possible to prevent a situation in which the adjustment value of the printer is set by using a scanner whose generated input value is abnormal. Therefore, the adjustment value of the printer can be accurately set even if a scanner whose performance is likely to change with time as compared with the colorimeter is used. In addition, if a scanner is used, data can be obtained for a plurality of print results (patches) at a time, so that printer adjustment values can be set in a short time for a plurality of print modes.

  Further, in the image processing system 10 of the present embodiment, it is confirmed whether or not the periodic inspection of the scanner 400 is performed within a predetermined time prior to setting the adjustment amount for the printer 500t flowing on the production line (FIG. 15 step S505). If the periodic inspection is not performed within a predetermined time, a warning is displayed (step S507). For this reason, even if the image reading table of the scanner becomes dirty or the lamp of the image reading table is burned out within 24 hours, for example within 24 hours, the correct output value cannot be output. It is possible to prevent a situation in which the adjustment value of the printer is set using the scanner in such a state.

  The scanner reads an image in an area wider than that of the colorimeter on the image reading table. Further, in many cases, reading is performed by placing a reading target such as a sample chart SC on an image reading table installed horizontally. Therefore, the possibility that the image reading table becomes dirty and the reflected light to be read does not accurately reach the sensor is much higher than the possibility that the reading unit of the colorimeter becomes dirty. Therefore, as in this embodiment, prior to setting the adjustment amount of the printer, checking whether the periodic inspection is performed within a predetermined time is to set the adjustment value of the printer using the scanner. This is particularly effective when

  Further, in the image processing system 10 of the present embodiment, when the LUT file is generated, the number of days elapsed from the color measurement date by the colorimeter 300 (step 450 in FIG. 7) and the number of days elapsed from the reference chart BC production date. Determination (step S460 in FIG. 7) is performed. Therefore, misuse of the colorimetric value file MF and misuse of the reference input value file BIF can be prevented. Further, in the image processing system 10 of the present embodiment, when the LUT file is used, the elapsed days from the LUT file generation date is determined (step S530 in FIG. 15). Therefore, misuse of the LUT file can be prevented. Therefore, according to the image processing system 10 of the present embodiment, the image input value by the scanner 400 and the image colorimetric value by the colorimeter 300 can be associated efficiently and accurately.

  In the image processing system 10 of the present embodiment, the adjustment amount setting process of the printer 500t that performs printing using four colors of ink can be performed using only one color of black ink, and the print adjustment amount setting process is performed. Can be done efficiently.

C. Variations:
The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

C1. Modification 1:
In the above embodiment, the first and second areas A1 and A2 in which the read values are used when the patch input values R1 and R2 are obtained are areas that do not overlap each other. However, the first and second regions A1 and A2 may partially overlap. That is, the first and second regions A1 and A2 only need to include regions that do not overlap with the other.

  In the above embodiment, the patches whose colors are read by the scanner 400 or the colorimeter when the LUT file is generated or when the scanner 400 is inspected are areas separated from each other. However, the areas read in those cases may be in contact with each other. That is, the area where the color is read by the scanner 400 or the colorimeter when the LUT file is generated or the scanner 400 is inspected may be an area having a single color. It is assumed that the “single color” includes an achromatic color, and the achromatic colors having different brightness values are not “a single color”.

  In the above embodiment, the first and second areas A1 and A2 are within the area surrounded by the line B1 that is 1/8 of the side length L1 and L2 from the outer contour of the patch. . However, the first and second regions A1 and A2 may be closer to the outer contour of the patch. That is, the first and second areas A1 and A2 in which the reading values are used when obtaining the patch input values R1 and R2 may be included in the patch area. However, the first and second regions A1 and A2 are preferably in a region surrounded by a line B1 that is 1/8 of the length L1 and L2 of each side from the outer contour of the patch. It is preferable that the outer contour of the patch is within a region surrounded by the inner line by 1/6 of the side lengths L1 and L2.

  The first and second regions A1 and A2 are rectangular, and the length of each side is 1/4 of the length of the side of the patch parallel to them. However, the sides of the first and second regions A1 and A2 can have other lengths. However, the length of each side is preferably ¼ or less of the length of the side of the patch parallel to them, and more preferably １ ／ or less. On the other hand, the length of each side of the first and second regions A1, A2 is preferably 1/10 or more of the length of the side of the patch parallel to them, and more preferably 1/8 or more. It is preferable to use a length. Further, the shapes of the first and second regions A1 and A2 can be square, and can be other polygons or circles.

  In the above-described embodiment, the first and second areas A1 and A2 in which the reading values are used when the patch input values R1 and R2 are obtained are predetermined areas on the scanner 400 side. The first and second areas A1 and A2 are areas located within the area of each patch of the reference chart BC-i when the reference chart BC-i is correctly positioned on the image reading table of the scanner 400. there were. However, the first and second regions A1 and A2 may be determined according to the input values generated after the scanner 400 reads the reference chart BC-i. That is, based on the R value generated for each pixel, the outline of the patch may be obtained, and pixel areas A1 and A2 located inside the outline may be set.

C2. Modification 2:
In the above embodiment, the magnitude of the difference ΔR between the input values R1 and R2 generated by reading the first and second areas A1 and A2 is j = in all reference charts BC with i = 1 to N. With respect to all the patches 1 to 24, it is determined whether to stop the process and generate the LUT file by displaying a warning depending on whether or not the patch is equal to or less than the predetermined value Thr (step S435 and FIG. 7 in FIG. 7). 4 upper display 122). However, whether or not to display a warning may be determined by other methods.

  For example, whether or not to display a warning may be determined based on whether or not there are more than a predetermined number of ΔR whose absolute value exceeds a predetermined value Thr. Further, the sum of squares of ΔR is calculated for the patches of j = 1 to 24 of each reference chart BC of i = 1 to N, and the sum is determined based on whether the magnitude is larger than a predetermined value Thr2. May be. That is, whether or not to display a warning may be determined based on whether or not the first and second input values R1 and R2 are closer than a predetermined reference.

C3. Modification 3:
Various types of image input devices and colorimeters can be used. For example, the image input apparatus may have a reading table or may not have a reading table. Also, the colorimeter can have its own light source, or it does not have its own light source and measures the color of an object based on the reflected light of another light source. May be.

  However, it is preferable that the image input device is capable of simultaneously reading the colors of a plurality of target portions and generating a plurality of input values representing the color characteristics of each target portion. Further, it is preferable that the colorimeter is capable of reading the color of the target portion and generating a colorimetric value representing the color characteristic of the target portion with higher accuracy than the image input device. Note that “higher accuracy than the image input device” means that the same object is read a predetermined number of times with the image input device and the colorimeter, and repeated for a certain period of time. This means that the rate of increase is small.

C4. Modification 4:
In the above embodiment, the reference input value file BIF1 is generated by adding the production date of the reference chart BC to the original input value file BIF1. That is, the R value of the reference input value file BIF is R1 that is the R value of each patch included in the original input value file BIF1. However, the R value of the reference input value file BIF can be obtained by other methods. For example, an average value of the image input values R1 and R2 for the same patch included in the original input value file BIF1 and the comparison input value file BIF2 may be used as the image input value of the reference input value file BIF. That is, any input value that represents the color characteristics of the patch may be obtained based on at least one of the input values that represent the color characteristics of the first and second regions.

C5. Modification 5:
In the above embodiment, when the LUT file is created, the input values are obtained by averaging the R values at two locations (region A1 and region A2) in the patch of the reference chart BC (FIGS. 4 and 9). reference). However, when the sample chart SC or the inspection chart CC is imaged, similarly, the input values may be obtained by averaging the R values at two locations (area A1 and area A2) in the patch.

  That is, when generating the adjustment data, first, (a) the image input device is inspected, and inspection data including inspection time data is generated when the inspection result satisfies a predetermined condition. On the other hand, if the result of the inspection does not satisfy a predetermined condition, a warning is issued. When the image input device is inspected, the following processing is performed. That is, first, (a1) a predetermined color area for inspection is measured with a colorimeter to obtain a reference colorimetric value that is a colorimetric value corresponding to the color area for inspection. On the other hand, (a2) the inspection monochrome region is imaged by the image input device, and an inspection input value which is an input value corresponding to the inspection monochrome region is obtained. Thereafter, (a3) using the conversion data, the inspection input value is converted into an inspection colorimetric value that is a colorimetric value corresponding to the inspection monochrome region. The predetermined condition for generating the inspection data is that the inspection color measurement value and the reference color measurement value are closer to the predetermined standard.

  Furthermore, when obtaining the inspection input value, the first part included in the monochrome region is read by the input device, and the first input value corresponding to the first part is obtained. In addition, a second portion that is included in the monochrome region and is different from the first portion is read by the input device, and a second input value corresponding to the second portion is obtained. Then, when the first and second input values are closer than a predetermined reference, an inspection input value corresponding to the monochrome area is obtained based on at least one of the first and second input values. On the other hand, if the first and second input values are not closer than a predetermined reference, a warning is issued.

  With such an aspect, the performance of generating the input value of the image input device can be accurately evaluated using the colorimeter, and the image input device can be checked. Then, it can be confirmed that there is no abnormality in the function of generating the input value of the image input device, and a highly reliable inspection can be performed. The above processing is performed when a patch (monochromatic area for adjustment) in the sample chart SC is imaged by a scanner (image input device) to obtain a target input value that is an input value representing the color characteristics of the patch. Also good.

C6. Modification 6:
In the above embodiment, among the L ^* value of each patch of inspection input value file CIF2, deviation from the L ^* value of the corresponding colorimetric value file CMF based on whether there is more than a predetermined value, the scanner It was determined whether or not to update the inspection time (step S368 in FIG. 13). However, whether or not to update the scanner check time may be determined by another method. For example, among the ^{L *} value of each patch of inspection input value file CIF2 (Figure 14), the corresponding patch colorimetric value file MF reference chart BC-M (i.e., inspection charts CC) (FIG. 4) ^{L *} You may determine based on whether the magnitude | size of deviation | shift from a value was beyond a predetermined value. That is, it can be determined based on whether or not the inspection colorimetric value (L ^* value) of each patch in the inspection input value file CIF2 is within a predetermined range.

  Whether or not to update the inspection time of the scanner may be determined as follows. For example, among the R values of each patch in the inspection input value file CIF1 (FIG. 14), the R value of the corresponding patch in the reference chart BC-M (that is, the inspection chart CC) in the reference input value file BIF (FIG. 4). It may be determined based on whether or not there is a deviation of a predetermined value or more. That is, it can be determined based on whether or not the input value of each patch in the inspection input value file CIF1 is within a predetermined range including the input value (R value) of the corresponding patch in the reference chart BC-M. .

C7. Modification 7:
In the above embodiment, the scanner as the image input device reads the target color, and uses the R value, G value, and B as evaluation values of the red, green, and blue components as input values representing the characteristics of the color. The value could be output. However, the image input device may be, for example, a device that can read the target color and output any of the R value, the G value, and the B value, or can output only the brightness. In other words, the image input device only needs to be able to read the color of the target portion and generate a value representing the color characteristic. As the image input device, for example, a digital still camera may be employed in addition to the scanner.

C8. Modification 8:
In the above embodiment, a warning issued in a predetermined case is displayed on the display 120 of the computer 100 (see the upper part of FIG. 4, the lower left part of FIG. 14, the upper right part of FIG. 16, etc.). However, these warnings may be made in other ways. For example, a voice warning may be issued, or a lamp may be turned on to issue a warning. That is, the warning may be any warning that prompts the user to stop the acquisition of the colorimetric value by the image input apparatus or the setting of the adjustment amount of the printing apparatus.

C9. Modification 9:
In the above embodiment, the inspection time of the image input apparatus (scanner 400) referred to before setting the adjustment value of the printing apparatus is the imaging time of the inspection chart CC (see the upper right in FIG. 14). However, the inspection time of the image input device can be another time. For example, it is confirmed that there is no significant change in the performance of the image input device, and as a result, the time when the inspection data is stored in the external storage device 140 can be set (see the lower left in FIG. 14). That is, the data on the inspection time of the image input device may be any data that substantially represents the time at which the process (see FIG. 15) at any stage of the inspection processing of the image input device is performed. Further, the inspection time data may be stored in a format other than the date and the hour and minute.

C10. Modification 10:
In the above embodiment, the image processing system 10 is used for setting the adjustment amount B of the printer. However, the image processing system 10 corresponds to the correspondence between the image input value by the image input device and the image colorimetric value by the colorimeter. It can be used for other purposes as long as it is attached.

C11. Modification 11:
In the above embodiment, the elapsed days determination unit 230 of the image processing system 10 determines the elapsed days from the colorimetric date, the elapsed days from the reference chart BC production date, the elapsed days from the LUT file generation date, The determination of the elapsed time from the scanner inspection time is performed, but it is not always necessary to perform all of these four determinations, and any determination may be made as long as the elapsed time from the scanner inspection time is determined.

C12. Modification 12:
The reference chart BC and the sample chart SC used in the above embodiment are merely examples, and other charts can be used. For example, in the above-described embodiment, the sample chart SC is a single sheet printed with black ink using 24 patches that are different from each other in ink nozzle, dot diameter, and print mode (resolution) used for printing. there were. However, the sample chart SC is, for example, a patch having the same ink nozzle, dot diameter, and printing mode (resolution), and printed by printing methods with different relative feeding methods between the printing head of the printing apparatus and the printing medium. May be included. That is, the sample chart SC only needs to include patches printed by different methods using the printing apparatus. If at least one of the ink nozzle used for printing, the dot diameter, the printing mode (resolution), and the relative feeding method between the print head and the printing medium is different, it corresponds to “different method”. Shall. Further, the sample chart SC may include a plurality of patches that are printed based on color designation values that designate colors with different brightness.

  In the above embodiment, the reference chart BC and the sample chart SC are all printed using only one black ink, but cyan, magenta, yellow, light cyan, and light magenta that are originally used for the ink nozzles of the printer. You may print using ink, such as.

C13. Modification 13:
The configuration of the image processing system 10 in the above embodiment is merely an example, and the image processing system 10 can have other configurations. For example, the image processing system 10 may include a digital camera instead of the scanner 400 as an image input device. In this embodiment, an ink-jet printer using four color inks of C, M, Y, and K is used as the printer 500 of the image processing system 10. For example, LC (light cyan), LM (light It is also possible to use other printers such as an ink jet printer that uses six colors of ink including two colors (magenta) and a printer other than the ink jet printer.

1 is an explanatory diagram schematically showing the configuration of an image processing system as a first embodiment of the present invention. FIG. 6 is a flowchart showing a flow of print adjustment amount setting processing by the image processing system of the present embodiment. The flowchart which shows the flow of a preparation process of reference | standard chart BC. FIG. 5 is an explanatory diagram showing an overview of processing for preparing a reference chart BC and processing for preparing an LUT file in the print adjustment amount setting processing. Explanatory drawing which shows the content of reference | standard chart BC roughly. The flowchart which shows the flow of a process of preparation of a LUT file. 7 is a flowchart showing a flow of LUT file generation processing in step S400 of FIG. Explanatory drawing which shows an example of the colorimetric value file MF. The figure which shows the method of imaging the reference | standard chart BC and producing | generating the original input value file BIF1 and the comparison input value file BIF2. The figure which shows an example of the original input value file BIF1 and the comparison input value file BIF2. Explanatory drawing which shows an example of the reference | standard input value file BIF. Explanatory drawing which shows an example of a LUT file. 6 is a flowchart showing a flow of inspection processing of the scanner 400. The figure which shows the data produced in the case of the inspection of the scanner 400. FIG. The flowchart which shows the flow of a process of adjustment amount B setting. The figure which shows the outline | summary of the process of an adjustment amount B setting among printing adjustment amount setting processes. Explanatory drawing which shows ideal relationship IR roughly.

Explanation of symbols

10. Image processing system 100 ... Computer 110 ... CPU
120 ... display part (display)
130 ... Operation unit 140 ... External storage device 150 ... Timer 160 ... Interface unit 170 ... Bus 200 ... Internal storage device 210 ... LUT generation unit 212 ... LUT generation date Additional unit 220 ... Print adjustment amount setting unit 222 ... Conversion unit 230 ... Elapsed days determination unit 240 ... Color measurement processing unit 242 ... Color measurement date addition unit 250 ... Imaging processing unit 252 ... Date input / addition unit 254 ... Input value determination unit 260 ... Print processing unit 270 ... Imaging inspection unit 300 ... Colorimeter 400 ... Scanner 500, 500t ... Printer A1 ... first area (part)
A2 ... second area (part)
B ... Adjustment amount BC ... Reference chart BF ... Adjustment amount data BIF ... Reference input value file BIF1 ... Original input value file BIF2 ... Comparison input value file Bj ... Adjustment amount CC ... Check chart CIF1 ... Check input value file including R value CIF2 ... L ^* Check input value file including value CMF ... Colorimetric value file G ... Gradation value of image data IR. .. Ideal relationship L ^* ... L ^* a ^* b ^* Lightness in the color system MF ... Colorimetric value file SC ... Sample chart SCF ... Sample conversion file SIF ... Sample input value file i ... Sheet number j ... Patch number p1 ... First point p2 ... Second point ΔL ^* ... L ^* of the corresponding patch in the colorimetric value file CMF and the inspection input value file CIF2 Difference in value ΔR ... Difference between input values R1 and R2 of the first and second areas included in the same patch

Claims (7)

A method of generating conversion data for storing an input value generated by an image input device and a colorimetric value generated by a colorimeter in association with each other,
(A) reading a color of a reference chart including a single color area having a single color with a colorimeter to obtain a colorimetric value representing a color characteristic of the single color area;
(B) reading the color of the reference chart with an image input device to obtain an input value representing a color characteristic of the monochrome region;
(C) generating conversion data for storing the colorimetric value and the input value in association with each other,
The step (b)
(B1) reading the color of the first part included in the monochromatic region with the image input device to obtain a first input value representing the color characteristic of the first part;
(B2) obtaining a second input value representing a color characteristic of the second part by reading, with the image input device, a second part that is included in the monochromatic region and different from the first part; ,
(B3) When the first and second input values are closer than a predetermined reference, the color characteristics of the monochrome region are expressed based on at least one of the first and second input values. Obtaining the input value;
And (b4) issuing a warning when the first and second input values are not closer than a predetermined reference. The method of claim 1, comprising:
The step (a)
A method comprising: reading a color of a third portion included in at least one of the first and second portions with the colorimeter to obtain a colorimetric value corresponding to the monochrome region. The method of claim 1, comprising:
The method wherein the first and second portions are regions separated from each other within the monochrome region. A method for generating adjustment data for correcting printing characteristics of a printing device using an image input device,
(D) generating the conversion data by the method according to any one of claims 1 to 3;
(E) preparing color reproduction target data for storing colorimetric values representing the characteristics of colors to be reproduced by the printing apparatus when given a color designation value for designating a predetermined series of colors;
(F) printing a single color area for adjustment having a single color on the printing device based on a sample color designation value that is a color designation value that designates a sample color included in the predetermined series;
(G) imaging the single color area for adjustment with the image input device to obtain a target input value that is an input value representing a color characteristic of the single color area for adjustment;
(H) using the conversion data, converting the target input value into a target colorimetric value that is a colorimetric value representing a color characteristic of the adjustment single-color region;
(I) using the color reproduction target data, converting the target colorimetric value into an ideal designated value that is a color designated value corresponding to the single color area for adjustment;
(J) generating the adjustment data based on the sample color designation value and the ideal designation value. A method of manufacturing a printing apparatus,
Generating the adjustment data with the method of claim 4;
Storing the adjustment data in a storage unit of the printing apparatus. A system for generating conversion data for storing an input value generated by an image input unit and a colorimetric value generated by a colorimeter in association with each other,
An image input unit capable of simultaneously reading the colors of a plurality of target portions and generating input values representing the color characteristics of the target portions;
A colorimetric unit capable of reading the color of the target part and generating a colorimetric value representing the color characteristic of the target part with higher accuracy than the image input unit;
A colorimetric processing unit that reads a color of a reference chart including a single color region having a single color with a colorimeter, and obtains a colorimetric value representing a color characteristic of the single color region;
An image processing unit that reads the color of the reference chart with an image input unit and obtains an input value representing a color characteristic of the monochrome region;
A conversion data generation unit that generates conversion data for storing the colorimetric value and the input value in association with each other;
The imaging processing unit
A first input value representing a color characteristic of the first portion obtained by reading the color of the first portion included in the single color region by the image input unit; and the first input value included in the single color region. A second input value representing a color characteristic of the second portion obtained by reading the second portion different from the second portion with the image input unit is closer than a predetermined reference Obtaining the input value representing a color characteristic of the monochrome region based on at least one of the first and second input values;
A system that issues a warning when the first and second input values are not closer than a predetermined reference. A computer program for generating conversion data for storing an input value generated by an image input device and a colorimetric value generated by a colorimeter in association with each other,
A function of reading a color of a reference chart including a single color area having a single color with a colorimeter and obtaining a colorimetric value representing a color characteristic of the single color area;
A function of reading the color of the reference chart with an image input device and obtaining an input value representing a color characteristic of the monochrome region;
A function of generating conversion data for storing the colorimetric value and the input value in association with each other;
A function of reading a color of a first portion included in the monochromatic region with the image input device to obtain a first input value representing a color characteristic of the first portion;
A function of obtaining a second input value representing a color characteristic of the second portion by reading a second portion that is included in the monochrome region and different from the first portion with the image input device;
The input value representing a color characteristic of the monochrome region based on at least one of the first and second input values when the first and second input values are closer than a predetermined reference. With the ability to get the
A computer program for causing a computer to realize a function of issuing a warning when the first and second input values are not closer than a predetermined reference.

Images