JP4604617B2 - Color chart evaluation system, color chart printing apparatus, color chart colorimetry apparatus, color chart evaluation method, color chart printing method, and color chart colorimetry method - Google Patents

Description

  The present invention relates to a color chart evaluation system, a color chart printing apparatus, a color chart colorimetry apparatus, a color chart evaluation method, a color chart printing method, and a color chart colorimetry method.

Conventionally, as this type of color chart evaluation system, a color patch of a color corresponding to an image input device is formed on the color chart, and the color input of the color patch is discriminated to identify the target image input device. Are known (see, for example, Patent Document 1, Paragraph 0101).
According to this configuration, the target image input device can be specified without manually inputting information of the image input device, so that the operation can be simplified and the target image input device can be specified. Was prevented from being mistakenly recognized.
JP 2001-177725 A

In the above-described color chart, if the type of discrimination target is limited to some extent as in the image input device, the discrimination target can be specified by defining the correspondence with the color of the color patch in advance. However, in the case of a discrimination target that can exist indefinitely and infinitely, such as date and time, it is impossible to predefine the correspondence with the color patch, and the date and time are discriminated from the color patch. There was a problem that we could not do it.
The present invention has been made in view of the above problems, and provides a color chart evaluation system, a color chart printing apparatus, a color chart colorimetry apparatus, a color chart evaluation method, and a color chart capable of transmitting all kinds of information about the formation conditions of a color chart. An object is to provide a printing method and a color chart colorimetry method.

Means and actions / effects for solving the problems

  In order to achieve the above object, in the first aspect of the invention, the color chart evaluation system includes a color chart printing apparatus and a color chart colorimetry apparatus. The color chart printing apparatus forms a color chart including a plurality of color patches with colors in a predetermined area on a recording medium. The color chart colorimetry apparatus evaluates the color chart by measuring each color patch of the color chart.

  The color chart printing apparatus includes condition acquisition means, and the condition acquisition means acquires the formation conditions of the color chart. The character string forming unit expresses the formation condition acquired by the condition acquisition unit by a combination of a plurality of characters. The color specifying means specifies a color corresponding to the character expressing the formation condition by combining a plurality of colors. Further, the condition evaluation color patch forming unit forms the color patch to which the color specified by the color specifying unit is added. The color patch formed in this way is referred to as a condition evaluation color patch. On the other hand, the condition evaluation color patch forming means forms the color patch with the sample color on the recording medium. The color patch with the sample color is referred to as a color patch for color evaluation.

  The color chart colorimetric apparatus includes character specifying means, and the character specifying means specifies the character corresponding to the colorimetric value obtained by measuring the color patch for condition evaluation. The decoding means decodes the formation condition based on the character specified by the character specifying means and the array of color patches for condition evaluation. Further, the color evaluation unit evaluates the color patch for color evaluation based on the formation condition decoded by the decoding unit.

  With this configuration, the color chart colorimetric device can recognize the formation conditions of the color chart via the condition evaluation color patch. Therefore, in the color chart colorimetry apparatus, the color evaluation color patch can be evaluated according to the formation conditions of the color chart. Furthermore, the color chart printing apparatus expresses the formation conditions by a character string, and forms the condition evaluation color patch in which a character corresponding to the same character is attached to each character constituting the character string. Then, the color chart colorimetric apparatus performs decoding based on the colorimetric values and arrangement of the condition evaluation color patches, and reproduces the formation conditions.

  The arrangement and combination of the condition evaluation color patches are infinite. Therefore, an infinite character string can be expressed by associating the character with each condition evaluation color patch. That is, the formation conditions of any color chart can be expressed by a plurality of condition evaluation color patches. Therefore, unpredictable information such as the printing date and time of the color chart and the machine number of the color chart printing apparatus can be transmitted to the color chart colorimetry apparatus.

  Furthermore, as an example of a method in which the color chart colorimetric device identifies a character corresponding to the condition evaluation color patch, the invention according to claim 2 is a correspondence between the character and a color value of a color corresponding to the character. A character specifying table for defining the relationship is provided, and the character specifying means refers to the character specifying table to specify the character corresponding to the colorimetric value obtained by measuring the color patch for condition evaluation. That is, by preparing a character specification table that defines the correspondence between the character and the color value of the color corresponding to the character, the character corresponding to the color value of the condition evaluation color patch is specified. be able to.

  In addition, as an example of a suitable technique for specifying the corresponding character from the colorimetric values of the condition evaluation color patch, the invention according to claim 3 includes the color value described in the character specifying table and the color value described above. A color difference from the colorimetric value obtained by measuring the color patch for condition evaluation is calculated, and it is determined whether the color difference is within a predetermined allowable range. If it is within the allowable range, it is determined that the condition evaluation color patch corresponds to the character associated with the color value. In this way, even if there is a variation in the color reproducibility on the color chart to some extent, the corresponding character can be specified from the colorimetric values of the condition evaluation color patch.

  Furthermore, as a preferred example of the character specifying table, in the invention according to claim 4, the condition evaluation color patch forming means forms a sample area on the recording medium. In this sample area, the condition evaluation color patches having colors corresponding to the characters that can be used are arranged. On the other hand, the character specifying means measures the color patch for condition evaluation in the sample area, and updates the color value described in the character specifying table with the colorimetric value. That is, the color value described in the character specification table can be updated by the result of actual measurement of the condition evaluation color patch in the sample area. Therefore, even when the color reproducibility of the condition evaluation color patch varies depending on the recording medium, the color value suitable for the recording medium is described in the character identification table, and the condition evaluation color is accurately determined. The corresponding character can be specified from the colorimetric value of the color patch.

  In addition, as an example of a technique for accurately identifying the corresponding character from the colorimetric values of the condition evaluation color patch, the invention according to claim 5 uses the colorimetric values of the condition evaluation color patch in the sample region. When the color value described in the character specification table is updated, the allowable range is narrowed. That is, by updating the color value of the character specification table with the colorimetric value of the condition evaluation color patch in the sample area, the color value can be updated to a value based on actual measurement. Thus, the allowable range can be narrowed. Thereby, it is possible to prevent the erroneous character from being specified from the colorimetric value of the condition evaluation color patch.

  The technical idea relating to the color chart evaluation system described above can also be realized in individual devices constituting the color chart evaluation system. Therefore, in claim 6, the invention is specified as a color chart printing apparatus, and in claim 7, the invention is specified as a color chart colorimetric apparatus. Furthermore, it can also be grasped as an invention of a method for realizing the technical idea of the color chart evaluation system described above, and the invention according to claim 8 has the same operations and effects as described above. Further, the color chart evaluation method described in claim 8 can be grasped independently of the color chart printing method and the color chart colorimetry method. Accordingly, claim 9 specifies the invention as a color chart printing method, and claim 10 specifies the invention as a color chart colorimetry method. Of course, it is also possible to grasp the invention dependent on each of claims 6 to 10 in the same manner as claims 2 to 5 dependent on claim 1.

Embodiments of the present invention will be described in the following order.
(1) Schematic configuration of color chart evaluation system:
(2) Color chart printing process:
(3) Color chart evaluation process:
(4) Application examples:
(5) Modification:

(1) Schematic Configuration of Present Embodiment FIG. 1 schematically shows a color chart evaluation system according to the present invention. In the figure, a client (CL) computer 10 and a plurality of printers 40, 40, 40... Constituting a color chart printing apparatus are connected to each other. On the other hand, a master (MS) computer 70 and a colorimeter 50 that constitute a color chart colorimetric apparatus are connected to each other. In the present embodiment, the color reproducibility of the plurality of printers 40 is an object of evaluation, and a color chart 60 for color chart evaluation is printed from each printer 40. Then, each color chart 60 printed is measured by the colorimeter 50, the obtained color values are taken into the computer 70, and a predetermined evaluation is performed to create correction data 90. The correction data 90 is stored in, for example, a CD-R. And the correction data 90 memorize | stored in CD-R is input into CL computer 10, and the correction | amendment with respect to each of several printers 40, 40, 40 ... is performed.

  FIG. 2 conceptually shows the hardware configuration and software configuration of the CL computer 10 and the printer 40 according to the present embodiment. The CL computer 10 includes a CPU (not shown) serving as the center of arithmetic processing, a ROM, a RAM, and the like as storage media, and executes a predetermined program using peripheral devices such as the HDD 15. An operation input device such as a keyboard 31 and a mouse 32 is connected to the computer 10 via a serial I / O 19a, and a display 33 is also connected via a video board (not shown). A printer 40a is connected via the USB I / O 19b. For the sake of simplicity, only the printer 40a among the printers 40 connected to the computer 10 is shown in FIG. A CD-ROM drive 34 capable of reading the correction data 90 stored in the CD-R is also connected to the USB I / O 19b.

  The printer 40a is provided with a mechanism in which ink cartridges filled with a plurality of colors of ink can be attached and detached for each color, and CMYK (cyan, magenta, yellow, black) ink cartridges are mounted on this mechanism. The printer 40a can combine these ink colors to form a large number of colors, thereby forming a color image such as the color chart 60 on the print medium. The printer 40a in the present embodiment is an ink jet printer, but the present invention can be applied to various printers such as a laser method in addition to the ink jet method.

  Furthermore, a configuration using four colored inks of CMYK is not essential, and various configurations such as a configuration using six colors of CMYKLcLm (light cyan, light magenta) and seven colors of CMYKLcLmDY (dark yellow) can be adopted. is there. In the computer 10, a printer driver (PRTDRV) 21, an input device driver (DRV) 22, and a display driver (DRV) 23 are incorporated in the OS 20. The display DRV 23 is a driver that controls display of a print target image, a printer property screen, and the like on the display 33, and the input device DRV 22 receives code signals from the keyboard 31 and mouse 32 input via the serial I / O 19a. A driver that receives and receives a predetermined input operation.

  The PRTDRV 21 can perform printing by performing a predetermined process on an image for which a print instruction has been made using an application program (not shown) or a predetermined color chart image. In the computer 10, printer drivers corresponding to the respective printers 40 connected in principle are installed. However, the PRTDRV 21 corresponding to the printer 40a will be described as a representative in FIG.

  The PRTDRV 21 includes a print condition setting module 21a, a print condition acquisition module 21b, a character string conversion module 21c, a header area data creation module 21d, an image composition module 21e, a color conversion module 21f, a halftone processing module 21g, and a print data generation module 21h. And an LUT correction module 21i. The LUT correction module 21 i is provided for correcting a color conversion LUT 18 described later, and the other modules 21 a to 21 h are provided for printing the color chart 60. When an operation for instructing printing of the color chart 60 is performed with the keyboard 31 or the mouse 32, the PRTDRV 21 is driven. Then, the PRTDRV 21 sends data to the display DRV 23 to display a user interface (UI) screen described later on the display 33.

  The printing condition setting module 21a accepts the printing conditions of the color chart 60 input according to this UI screen. Further, when a printing instruction is accepted on the UI screen, the printing conditions are determined. The confirmed printing conditions are input to the printing condition acquisition module 21b. The printing condition acquisition module 21b acquires the printing time from the timer 20a provided in the OS 20, and also acquires the printing conditions such as the machine number unique to each printer 40 from the printer 40a via the USB I / O 19b. The print conditions acquired from the modules 21a, 20a, and 19b in this way are input to the character string conversion module 21c, and the character string conversion module 21c converts the print conditions into a condition code expressed by the character arrangement. The

  Each print condition is converted into a character string into a code that can be handled by the CL computer 10 when it is input to the CL computer 10. The character string conversion module 21 c refers to the code list 19 and refers to an MS computer described later. In 70, the printing condition is converted into a decodable condition code. The printing condition converted into the condition code by the character string conversion module 21c is transferred to the header area data creation module 21d, and header area data as image data is generated based on the condition code. Specifically, the color specifying module 21d1 included in the header area data creating module 21d specifies the color value (RGB value) corresponding to each character constituting the condition code with reference to the color specifying table 16.

  Then, image data corresponding to the condition evaluation color patch is arranged in accordance with the arrangement rule preliminarily defined in the header area data creation module 21d, and each character constituting the condition code or the like is arranged for each arranged image data. Header area data is created by assigning pixels of color values to be processed. The header area data is formed as image data in which pixels represented by RGB gradation values are arranged. The header area data is input to the image synthesis module 21e, where it is synthesized with the color evaluation area data 17. At this time, a color patch for boundary definition is formed between the header area reproduced based on the header area data on the color chart and the color evaluation area reproduced based on the color evaluation area data 17. The image is synthesized.

  Similar to the header area data, the color evaluation area data 17 is prepared as image data in which pixels represented by RGB gradation values are arranged. The color evaluation area data 17 is printed based on the same color evaluation area data 17, so that color evaluation color patches having a plurality of sample colors can be arranged on the recording medium. The sample colors are determined so as to cover the entire color gamut reproducible by the printer 40 without any deviation. Further, similar color patches may be arranged so as to form a gradation.

  Image data formed by synthesizing the color evaluation area data 17 and the header area data in the image synthesis module 21e is input to the color conversion module 21f. The color conversion module 21f is a module that converts a color system indicating the color of each pixel, and refers to the color conversion LUT 18 recorded in the HDD 15 as appropriate, and uses the color ink in which the printer 40a mounts the sRGB color system of image data. Convert to CMYK color system as component. The color conversion LUT 18 is a table that expresses colors by using the sRGB color system and the CMYK color system, associates the colors, and describes the correspondence between a plurality of colors. Accordingly, with respect to an arbitrary color expressed in the sRGB color system, by referring to the sRGB color defined in the color conversion LUT 18 as a surrounding color, the CMYK color system corresponding to the arbitrary color can be obtained by interpolation calculation. Color can be calculated and color system conversion can be performed.

  When the color conversion system 21f converts the color system and obtains CMYK data, the halftone processing module 21g determines the gradation value of each pixel expressed in the CMYK color system to eject / not discharge ink in each pixel. The discharge is converted into the specified halftone image data. That is, ejection / non-ejection of ink droplets is determined for each pixel in the printer 40a. Needless to say, not only ink droplet ejection / non-ejection but also the amount of ejected ink can be controlled stepwise to determine the size of the ejected ink droplet.

  The print data generation module 21h receives the halftone image data, rearranges them in the order used by the printer 40a, and generates print data in units of data used in one main scan. The print data is sequentially output to the printer 40a via the USB I / O 19b. When all the data necessary for forming an image is transferred to the printer 40a, the printer 40a forms an image on a recording medium. And a color chart is created.

  The PRTDRV 21 includes an LUT correction module 21i. In the LUT correction module 21 i, correction data 90 created by the MS computer 70 is input via the CD-ROM drive 34, and the color conversion LUT 18 is corrected based on the correction data 90. Since the color conversion LUT 18 is a table that defines CMYK data, the color that is finally reproduced on the recording medium can be corrected by correcting the color conversion LUT 18. The correction data 90 may be input artificially using the keyboard 31 or the mouse 32, or may be input by a medium other than the CD-R storing the correction data 90. Furthermore, it may be input from a server on the Internet.

FIG. 3 conceptually shows the hardware configuration and software configuration of the MS computer 70 and the colorimeter 50 according to the present embodiment. The MS computer 70 has substantially the same configuration as the CL computer 70, but is connected to the colorimeter 50 via the USB I / O 79b. The colorimeter 50 irradiates the color chart 60 with a light source having a known spectral reflectance, detects the spectral reflectance of the printed matter by detecting the reflected light, and determines its color value, for example, the L ^* a ^* b ^* value, XYZ values can be output. In the present embodiment, the colorimeter 50 is driven by the colorimeter driver 82, and the color values (L ^* a ^* b ^* values) of the color patches in the color chart 60 printed by the printers 40 and the relevant values. The address of the color patch on the color chart 60 is acquired.

  The MS computer 70 incorporates an evaluation program 81 for evaluating the color chart 60. The evaluation program 81 includes a correction data creation module 81a, a color evaluation module 81b, a decoding module 81c, and a character identification module 81d. ing. The character specifying module 81d acquires the color value and address from the colorimeter 50 via the USB I / O 79b. And the character corresponding to the color value obtained by measuring the color patch for each condition evaluation is specified with reference to the character specifying table 75c. This character is sent to the decoding module 81c in association with the address of the color patch. The character specification table 75c is a table that defines the correspondence between the characters and the colors constituting the printing conditions, similar to the color specification table 16 described above.

  A character string made up of each character associated with the address of each condition evaluation color patch is decoded by the decoding module 81c. That is, the printing conditions recorded on the color chart 60 are reproduced by arranging characters obtained from a plurality of condition evaluation color patches on the basis of each address and decoding them according to a predetermined rule. At that time, the code list 75b stored in the HDD 75 is referred to. The printing conditions reproduced as described above are input to the color evaluation module 81b. On the other hand, the color evaluation module 81b compares the color value obtained by measuring the color patch for color evaluation with the reference value 75a stored in the HDD 75 in advance. At this time, a reference value 75a that is referred to according to the reproduced printing conditions is selected.

  The comparison result between the color value obtained by the color measurement and the reference value 75a is input to the correction data generation module 81a, and correction data 90 is generated if correction is necessary. Printing conditions are also input to the correction data creation module 81a, and correction data 90 corresponding to the printing conditions is created. The correction data 90 is output to the CDR drive 71 via the USB I / O 79 b and is recorded on the CD-R by the CDR drive 71. The correction data 90 recorded on the CD-R is input to the CL computer 10 and used for correcting the color conversion LUT 18.

(2) Color chart printing process:
FIG. 4 shows the flow of color chart printing processing performed by the CL computer 10. In the figure, when a printing instruction for the color chart 60 is received by the input device DRV 22, the printing condition acquisition module 21b acquires the printing conditions in step S100. The printing condition acquisition module 21b can input data from the printing condition setting module 21a, the timer 20a, and the USB / IO 19b, and acquires predetermined printing conditions from each information source.

  FIG. 5 shows a list of items of printing conditions acquired in step S100. In the figure, the machine number, printing date and time, printing paper, printing resolution, color tone, color patch size, number of color patches, and color chart number are acquired as printing conditions. The machine number is obtained from the printer 40a via the USB / IO 19b, the printing date and time is obtained from the timer 20a, and the printing paper, printing resolution, color tone, color patch size, number of color patches, and color chart number are obtained from the printing condition acquisition module 21b. To be acquired. The print condition acquisition module 21b receives input of each print condition in advance using the UI screen.

  FIG. 6 shows an example of a UI screen. In the figure, a color chart printing execution button is provided at the bottom of the UI screen. When the button is clicked, the color chart printing process after step S100 is executed and the printing conditions set at this time are confirmed. To do. Information about the confirmed printing conditions is input to the printing condition acquisition module 21b and stored in a table as shown in FIG. For example, since the printing paper is set to “super fine” on the UI screen, No. 56 corresponding to “super fine” is stored as data representing the contents of the printing paper. Similarly, the print resolution input on the UI screen is also stored.

  On the other hand, when the check box of the auto photo fine is checked, the auto photo fine is turned on, the predetermined color correction is executed when the predetermined color chart 60 is printed, and the table shown in FIG. No. 1 indicating that correction has been made is stored. When auto photo fine is set, color system conversion is performed using the color conversion LUT 18 corresponding to auto photo fine. Furthermore, by setting the color chart number on the UI screen, the layout of the color evaluation area in the color chart 60 can be specified, and the color patch size and the number of color patches in the table shown in FIG. 5 can also be specified.

  When the print condition as shown in the left column of FIG. 5 is acquired as described above, the print condition acquisition module 21b outputs the print condition to the character string conversion module 21c. In step S110, the character string conversion module 21c generates a condition code by converting the content of the print condition into a character string in a predetermined format. The right column of FIG. 5 shows a condition code obtained by converting the printing condition of each item into a character string. As shown in the same column, the contents of the printing conditions are expressed by hexadecimal numbers (0H, 2H, 3H ·· AH ·· FH) enumerated. The contents of the printing conditions originally expressed in numbers are converted into condition codes by converting them into hexadecimal numbers. On the other hand, the alphanumeric characters used for the machine number are condition-coded in the ASCII code format. For example, “ABC” used for the aircraft number is expressed as “4H, 1H, 4H, 2H, 4H, 3H” (shown in bold in the figure) using the ASCII code, and the other “0000123” is unchanged. It is expressed as “0H, 0H, 0H, 0H, 1H, 2H, 3H”. In the present embodiment, the above-described character string format is adopted.

  In the character string conversion module 21c, the condition code is generated by characterizing the contents of the printing conditions. However, the character string conversion module 21c does not necessarily perform the actual character string conversion. That is, when the contents of the printing conditions are input to the CL computer 10, they are converted into codes that can be handled by the CL computer 10, and if the code format is different from the character string format, the characters described above are used. If it is the same as the above format, it is stored as a condition code as it is. The condition code generated as described above is delivered to the header area data creation module 21d in step S120. The header area data creation module creates header area data based on the condition code.

  FIG. 7 shows a procedure for creating header area data. In the figure, an item code is inserted in step S121. Here, the item code is a head code for indicating what printing condition the character string (condition code) described later means. This item code is stored in the code list 19 stored in the HDD 15, and is read and used as appropriate by the header area data creation module 21d.

  FIG. 8 shows the code list 19 as a table. In the figure, item codes are expressed by combinations of two-digit characters, and meanings are associated with the combinations. For example, after the item code “C2, 1H”, a condition code indicating the machine number is described. Therefore, when the machine number shown in FIG. 5 is described, it is called “C2, 1H, 4H, 1H, 4H, 2H, 4H, 3H, 0H, 0H, 0H, 0H, 1H, 2H, 3H”. A string is formed. Further, in step S122, an auxiliary code is inserted. The auxiliary code is stored in the code list 19 together with the item code, and is expressed by a single digit character.

  FIG. 9 shows a table of condition codes in a state where item codes and auxiliary codes are inserted. In the same figure, for example, “SP” as an auxiliary code meaning a delimiter is inserted between the date and time of a condition code representing the printing date and time, thereby enabling proper interpretation of the printing date and time. Further, “EM” as an auxiliary code indicating the end is attached to the end of each condition code. Next, in step S123, the color corresponding to the characters constituting each item code, auxiliary code, and condition code is specified. Specifically, the color specifying module 21d1 specifies the color value corresponding to the characters constituting each code with reference to the color specifying table 16.

  FIG. 10 shows the color identification table 16. In the figure, the color specification table 16 defines a correspondence relationship between characters that can constitute each code and color values represented by RGB gradations. By referring to such a color specification table 16, it is possible to specify the RGB gradation value of the color corresponding to the characters (numbers) constituting each code. When the color value is specified in step S123, layout processing is executed in step S124. The layout processing generates image data (hereinafter referred to as patch data) corresponding to a plurality of condition evaluation color patches filled with the color of each character specified in step S123, and the patch data is generated. Arrange in a predetermined array.

  FIG. 11 shows an example of arrangement of patch data. In the figure, patch data is listed. In the figure, in order to express the arrangement of the patch data in an easy-to-understand manner, characters corresponding to the RGB gradation values of each patch data are attached as identification character strings. Pixels having tone values are filled in each region occupied by each condition evaluation color patch. The patch data corresponding to the printing conditions such as the machine number and the printing date / time is assigned to each condition item by one line, and the patch data corresponding to the item code representing each condition item is arranged in the first two columns. Yes.

  In the first two columns from the top to the third row, patch data corresponding to the item codes representing the character expression color samples 1 to 3 are arranged instead of the item codes representing the printing conditions. For example, the patch data of the color corresponding to “C1, SP” arranged in the first two columns of the first row means the character expression color sample 1 as shown in the code list 19 of FIG. In the column after the patch data corresponding to the item codes representing the character expression color samples 1 to 3, patch data of each color is generated so as to cover all the colors defined in the color specifying table 16. They are distributed in rows. The area occupied by the lines of the character expression color samples 1 to 3 is referred to as a sample area. The arrangement of patch data in the sample area is always constant without depending on the color chart number acquired in step S100.

  The patch data is composed of RGB gradation pixels of a color corresponding to each character, and the number of pixels is generated so as to conform to the resolution acquired in step S100. However, the size of the condition evaluation color patch and the position of the first row and first column are always constant without depending on the color chart number acquired in step S100. In step S125, the image data arranged by the patch data is output as bitmap data to the image composition module 21e. This bitmap data is referred to as header area data. In step S130, the image composition module 21e that has acquired the header area data attaches patch data corresponding to the color patch for boundary definition to the first column of the next line of the last line of the header area data. The color and character (auxiliary code) of the patch data corresponding to the color patch for boundary definition are defined in the code list 19 in FIG. 8 and the color specifying table 16 in FIG.

  Returning to FIG. 4, in step S140, the color evaluation area data is further combined with the header area data. A plurality of color evaluation area data 17 are stored in advance in the HDD 15, and data matching the color patch size, the number of color patches, the resolution, and the color chart number acquired in S100 are read out and used. The color evaluation area data 17 may be edited or generated according to the color patch size, the number of color patches, and the resolution acquired in S100. The color evaluation area data 17 is image data in which patch data corresponding to the color patches for color evaluation is distributed, and the color evaluation area data 17 is also stored as bitmap data. The color of the patch data corresponding to the color patch for color evaluation is a sample color set so as to cover the entire color gamut of the printer 40 without deviation. The color evaluation area data 17 is synthesized so that the first line starts from the next line of the patch data corresponding to the color patch for boundary definition. The synthesized image data is output to each module after the color conversion module 21f in step S150, and the color chart 60 based on the image data is printed by the printer 40a.

  FIG. 12 shows the color chart 60. In the figure, a header area in which printing conditions are expressed by a color patch for condition evaluation is formed at the top of the color chart 60, and a color patch with a sample color covering the color gamut of the printer 40a is formed below the header area. Arranged color evaluation regions are formed. In the figure, in order to express the arrangement of the color patches in an easy-to-understand manner, the characters corresponding to the color patches are attached as identification character strings. However, the color specified in step S123 is actually the color on each color patch. Has been reproduced. A boundary defining color patch is arranged between the header area and the color evaluation area.

(3) Color chart evaluation process:
FIG. 13 shows the flow of color chart evaluation processing performed by the MS computer 70. Hereinafter, a case where the color chart 60 in which the header area as shown in FIG. 12 is created is evaluated will be described as an example. In FIG. 13, in step S200, each value described in the character specification table 75c referred to by the character specification module 81d is reset to a default value.

FIG. 14 shows a character specification table. In the figure, the character specifying table 75c has the same configuration as the color specifying table 16 shown in FIG. 10, but the color measuring device 50 can obtain color values corresponding to each character in the character specifying table 75c of the MS computer 70. It is described as a value of the L ^* a ^* b ^* color system. In addition, the character specifying table 75c also describes the color difference values in the allowable range corresponding to each character. The default value of the allowable range is set to 10 for the color difference ΔE. In step S205, 1 is substituted into a variable n representing a row. In step S210, the process of the nth row in the color chart 60 is started. Since n = 1 at the initial stage, the color measurement of the first row in the header area is started. In step S215, the color measurement of the condition evaluation color patch in the first column in the nth row is performed.

  As described above, the position of the first row and first column of the condition evaluation color patch in the header area is always constant without depending on the color chart number acquired in step S100. Therefore, by setting the positions of the first row and the first column in the colorimeter 50 in advance, the color patches for condition evaluation of the first row and the first column can be captured in the field of view in any color chart 60. In addition, since the size of the condition evaluation color patch in the header area is also constant, by setting a predetermined size in the colorimeter 50 in advance, the second and subsequent rows and two columns in any color chart 60. The position of the color patch for condition evaluation after the eye can be specified and captured in the field of view.

In step S220, it is determined whether the L ^* a ^* b ^* value of the condition evaluation color patch obtained in step S215 is that of the boundary definition color patch. This refers to the character identification table 75c in the determination, and L ^* a ^* b ^* values obtained by L ^* a ^* b ^* values and colorimetry of the conditions described for evaluation color patches in the character identification table 75c The color difference (ΔE) is calculated. When the color difference ΔE is smaller than the allowable range, it is determined that the measured color patch is a boundary definition color patch. Note that the allowable range used for this determination is described in the character specification table 75c, and if it is the default, the color difference ΔE <10 is a condition.

In step S215, the color of the condition evaluation color patch having a color corresponding to the character “C1” is measured. Since the L ^* a ^* b ^* value obtained here is significantly different from the L ^* a ^* b ^* value of the color patch for boundary definition, step S225 is executed. In step S225, the visual field of the colorimeter 50 is moved in the row end direction by one column, and the L ^* a ^* b ^* value of the color patch for condition evaluation in the second column in the first row is acquired. In this case, the color patch for condition evaluation corresponding to the character “SP” is measured.

In step S230, it is determined which character corresponds to the L ^* a ^* b ^* value measured in steps S215 and S225 while referring to the character identification table 75c. The allowable range used for this determination is also described in the character specification table 75c, and the default color difference ΔE <10 is applied to both characters “C1, SP”. Further, the decryption module 81c refers to the code list 75b and specifies an item code composed of a combination of characters corresponding to the condition evaluation color patches in the first and second columns. Here, since the characters “C1, SP” are specified, it is specified to mean “character expression color sample 1” expressed by a combination thereof. Therefore, it can be determined that the condition evaluation color patch group in the first row corresponds to the character expression color sample 1.

Here, the color difference ΔE <10 is applied as an allowable range for both the characters “C1, SP”. However, as shown in FIG. 10, the color corresponding to the characters “C1, SP” is an extreme L ^* a ^* b. ^{* Because the} values are black and white, no recognition error will occur even if the tolerance is somewhat wide. In step S235, it is determined whether or not the item code decrypted in step S230 corresponds to “character expression color samples 1 to 3”. If so, step S240 is executed. In step S240, 3 is substituted into the variable m representing the column. In step S245, the color measurement of the condition evaluation color patch in the third column is performed to obtain the L ^* a ^* b ^* value.

In step S250, the L ^* a ^* b ^* value obtained in step S245 is updated and stored in the character identification table 75c. As described above, since the arrangement of the condition evaluation color patches in the sample area is constant in any color chart, specify which character the condition evaluation color patch in each column of the sample area corresponds to. Can do. Specifically, a sample arrangement table 75d that stores the arrangement of the condition evaluation color patches in the sample area is stored in the HDD 75, and the sample arrangement table 75d is referred to.

FIG. 15 shows a sample arrangement table 75d. In the figure, the sample arrangement table 75d defines characters arranged for each arrangement (m, n). Since the size of the condition evaluation color patch in the header area is always constant, the address on the color chart 60 can also be specified from the arrangement (m, n). For example, it is possible to specify that the color measurement of the condition evaluation color patch corresponding to the character “C2” is performed at n = 1 and m = 3. Then, updated and stored in the L ^* a ^* b ^* values of the corresponding character in the resulting L ^* a ^* b ^* values character identification table 75c at step S245. At the same time, the color difference ΔE <3 is updated and stored as the allowable range of the character whose L ^* a ^* b ^* value has been updated. That is, in step S250, the actual value of the condition evaluation color patch is defined in the character specification table 75c, and the allowable range is narrowed along with it.

In step S255, the sample arrangement table 75d is referred to, and it is determined whether or not the condition evaluation color patch measured in step S245 corresponds to the character “EM”. That is, it is determined whether or not the end of the line is reached. If the color patch for condition evaluation subjected to color measurement in step S245 does not correspond to the character “EM”, step S260 is executed. In step S260, 1 is added to m, and the process returns to step S245. In step S245 executed again, the color measurement of the condition evaluation color patch in the fourth column is performed. Also, steps S250 to S260 which are repeatedly performed are executed in the same manner as described above. In other words, the color measurement for the condition evaluation color patch in the first row is sequentially performed while shifting by one column, and the obtained L ^* a ^* b ^* values are sequentially updated in the character identification table 75c to narrow the allowable range. ing.

When m = 9, it is determined in step S255 that the color of the condition evaluation color patch corresponding to the character “EM” has been measured in the immediately preceding step S245. In this case, 1 is added to n in step S265, and processing for the next row is started in step S210. As shown in FIG. 12, since the second and third lines of the header area are also “character expression color samples 2 and 3”, steps S210 to S260 are repeatedly executed as described above. However, in the recognition of the character “C2” in the second column in step S230 executed for the second row, it is narrowed based on the L ^* a ^* b ^* value based on the actual measurement that has already been updated and stored. Whether or not the color patch for condition evaluation corresponding to the character “C2” is determined using the allowable range (color difference ΔE <3). Similarly, in the recognition of the character “C3” in the second column in step S230 executed for the third row, the actually measured L ^* a ^* b ^* value and the narrowed allowable range are used as a reference.

When the processing for the character expression color sample 3 is completed, the L ^* a ^* b ^* values are updated for all characters defined in the character specification table 75c, and the allowable range is narrowed for all characters. It becomes. This is because the sample area composed of the character expression color samples 1 to 3 is laid out so as to cover all the characters defined in the character specifying table 75c. When the processing for the sample area is completed, the processing for the fourth and subsequent rows is executed.

In the processes for the fourth and subsequent lines, the same processes as described above are performed up to steps S210 to S230. However, since the L ^* a ^* b ^* values and tolerances of the actual measurement for all characters defined in the character identification table 75c is updated, in the certification of the corresponding character in step S230, the actually measured L ^* a ^* b ^* values and narrowed tolerances will be used. In step S235, it is determined that the line does not belong to the sample area, and step S270 is executed. For example, when n = 4, since it is determined that the target line is not “character expression color samples 1 to 3” but a line describing the machine number, step S270 is executed. In steps S270 and S275, processing similar to that in step S240 is performed.

Of course, in the character determination in step S275, the actually measured L ^* a ^* b ^* value and the narrowed allowable range are used. In step S280, the character specified in step S275 is stored. In step S285, the L ^* a ^* b ^* value obtained in step S275 is compared with the actual L ^* a ^* b ^* value updated and recorded in the character identification table 75c, and the measurement is performed in step S275. It is determined whether or not the condition evaluation color patch for which color is applied corresponds to the character “EM”.

  In both step S255 and step S285, it is determined whether or not the condition evaluation color patch that has just undergone colorimetry corresponds to the character “EM”, but in step S255, it is based on the arrangement (m, n). However, the method is different in that the determination is made based on the color in step S285. If it is determined in step S285 that the color of the condition evaluation color patch that has just undergone colorimetry does not correspond to the character “EM”, 1 is added to m in step S290, and step S275 and subsequent steps are repeated. Execute. That is, it is recognized that the end of the row has not been reached, and the color measurement of the color patch for condition evaluation in the next column is continued.

  On the other hand, if it is determined in step S285 that the color of the condition evaluation color patch measured immediately before corresponds to the character “EM”, the character for one line stored in step S295 is stored. Decrypt the column. That is, based on the character string obtained from the condition evaluation color patches in the third and subsequent columns of the row currently being processed, decoding is performed to obtain printing conditions. Since each character is associated with an address on the color chart 60 of the character, the arrangement order of the characters can be specified. For example, in the row of n = 4, the characters “4H, 1H, 4H, 2H, 4H, 3H, 0H, 0H, 0H, 0H, 1H, 2H, 3H, EM” are cumulatively stored by repeated step S285. ing. Furthermore, the “EM” at the end is excluded, and “4H, 1H, 4H, 2H, 4H, 3H, 0H, 0H, 0H, 0H, 1H, 2H, 3H” is decrypted to obtain the aircraft number “ABC0000123”. Can be obtained.

  For example, in the row of n = 5, the characters “2H, 0H, 0H, 4H, AH, 1H, 5H, SP, 1H, 4H, 3H, 4H, EM” are accumulated by the repeated step S285. . Then, by removing the last “EM” and interpreting the delimiter code “SP” while decoding the remaining characters, the print date “October 15, 2004 14:34” can be obtained. it can. Each print condition decoded in this way is stored and used in later processing. In the example of FIG. 12, steps S210 to S235, steps S265, and steps S270 to S295 are repeatedly executed until n = 11. Therefore, it is possible to acquire information on the machine number, the printing date and time, the printing paper, the printing resolution, the color tone, the color patch size, the number of color patches, and the chart number.

  When n = 12, the boundary defining color patch is detected in step S220, and step S300 is executed. In step S300, the drying time is calculated by subtracting the current time by the timer 80a provided in the OS 80 from the printing date and time acquired as the printing condition. If the drying time is not ensured for a predetermined time (for example, 30 minutes) or longer, the process is stopped because the color of the ink is unstable. On the other hand, when the drying time is sufficiently secured, step S305 is executed.

In step S305, color measurement is performed on the color evaluation color patches formed in the 13th and subsequent rows. In step S310, the color evaluation module 81b compares the reference value 75a stored in the HDD 75 with the L ^* a ^* b ^* value obtained by measurement. For example, the color difference ΔE may be calculated. At this time, the reference value 75a to be compared is selected based on each printing condition acquired as described above. For example, since the arrangement of the color patches for color evaluation may differ depending on the chart number, it is necessary to compare with the reference value 75a adapted to the chart number. Further, since the colors to be compared differ when the color tone is different, it is necessary to select the reference value 75a corresponding to the color tone at the time of printing.

  In step S315, it is determined whether the color patch for color evaluation measured in step S305 is the final one. Here again, it is determined whether or not it is final based on the arrangement of the color patches for color evaluation depending on the chart number. If it is not final, step S305 is executed to measure the color of the next color patch for color evaluation. When performing color measurement of the next color patch for color evaluation, it is necessary to move the field of view appropriately, so the color patch size, the number of color patches, and the chart number acquired as printing conditions are used. The colorimeter driver 82 acquires information such as the color patch size, the number of color patches, and the chart number, and the colorimeter driver 82 drives the colorimeter 50 based on these information. On the other hand, when it is confirmed in step S315 that the color measurement of all color evaluation color patches has been completed, the correction data creation module 81a creates the correction data 90 in step S320.

  In the present embodiment, the color conversion LUT 18 is corrected by the correction data 90. However, since the color conversion LUT 18 is prepared for each color tone (APF on / off), print resolution, and printing paper, correction data 90 for correcting the color conversion LUT 18 used when the color chart 60 is printed is created. Without it, there is no point. Further, since many printers 40 are connected to the CL computer 10, it is meaningless unless correction data 90 for correcting the color conversion LUT 18 of the printer 40 that has printed the color chart 60 is created. Accordingly, in step S320, identification data for specifying the printer 40 and the color conversion LUT 18 to be corrected based on the machine number, the printing paper, the printing resolution, and the color tone acquired as the printing conditions from the color chart 60 are attached. By doing so, it is possible to correct the color conversion LUT 18 of the printer 40 used when the color chart 60 is printed without mistake.

  In the present embodiment, printing conditions are recorded on the color chart 60, and the printing conditions are acquired by the colorimeter 50 and the MS computer 70. By doing this. It is possible to evaluate a color patch for color evaluation and create correction data 90 according to the printing conditions for creating the color chart 60. In recording the printing conditions on the color chart 60, the color of the color patch for condition evaluation is associated with the characters expressing the printing conditions. Therefore, various printing conditions can be decoded by measuring the color of the condition evaluation color patch. Since this combination of characters can be considered almost infinitely, it is possible to express any printing condition by following a predetermined grammar.

Further, the color of the color patch for condition evaluation arranged in the sample area is measured in advance, and the L ^* a ^* b ^* value is updated in the character identification table 75c. That is, when the character is specified from the L ^* a ^* b ^* value with reference to the character specifying table 75c, the determination is made by comparing with the L ^* a ^* b ^* value actually measured in the color chart 60. be able to. Therefore, for example, even when the color of the condition evaluation color patch varies depending on the printing paper on which the color chart 60 is recorded, the character specification table 75c suitable for the printing paper can be defined. Therefore, it is possible to accurately specify characters from the colorimetric values using the character specifying table 75c. In addition, since the allowable range of the color difference ΔE is narrowed accordingly, accurate recognition of the printing conditions can be realized without more erroneous recognition.

It should be noted that when characters are specified from the colorimetric values of the condition evaluation color patch using the character specification table 75c in steps S230 and S285, the L ^* a ^* b ^* values measured in the allowable range of any character. It may be possible that does not enter. In this case, the processing may be interrupted as a printing condition recognition error. In the present embodiment, a boundary defining color patch is arranged between the header area and the color evaluation area. By doing in this way, the boundary of a header area | region and a color evaluation area | region can be recognized reliably. Therefore, it is possible to prevent the printing condition from being acquired from the color of the color patch for color evaluation in the color evaluation area. Further, the drying time is automatically calculated, and when the drying time is insufficient, the color measurement in the color evaluation area is stopped. By doing so, it is possible to prevent the generation of inaccurate correction data 90 based on the color chart 60 having an unstable color, and it is possible to prevent time from being used for wasteful color measurement.

(4) Application examples:
By applying the present invention, the printing conditions can be acquired from the color chart 60 and the correction data 90 corresponding to the printing conditions can be created without inputting the printing conditions in the MS computer 70. In other words, even if the side operating the MS computer 70 and the side operating the CL computer 10 are not closely related, it is possible to perform appropriate correction. That is, if the color chart 60 and the correction data 90 can be exchanged between the two, appropriate correction can be performed. For example, the MS computer 70 may be owned by the manufacturer of the printer 40, receive a color chart 60 from each client, and perform a service such as sending correction data 90 to each client.

  By doing so, it is possible to perform appropriate correction without performing an operation of specifying a correction target from a plurality of printers 40 and color conversion LUTs 18 in each client. Further, it is not necessary to record under which printing conditions the color chart 60 is printed. Therefore, the color reproducibility as intended by the manufacturer of the printer 40 can be realized without requiring special knowledge in the printer 40 of each client. The correction data 90 may be sent using the Internet or the like.

  In addition, it is conceivable that the colorimeter 50 is owned by a printing company that performs printing in large quantities. In that case, the MS computer 70 and the colorimeter 50 may be provided at the head office of the printing company, and the color chart 60 may be output by the printer 40 at each branch. By doing so, the color reproducibility of a large number of printers 40 provided at each branch can be matched, and the same print result can be obtained at any fulcrum. In addition, a large number of printers 40 are installed in the printer, but since the machine number is specified in the color chart 60, it is not unclear which printer 40 is the correction target.

  In the above embodiment, the CL computer 10 and the MS computer 70 are provided separately. However, a system configuration in which the functions of the CL computer 10 and the MS computer 70 are realized on the same computer may be adopted. Further, as an example, the color conversion LUT 18 is corrected, but it is sufficient that the printing condition is recognized via the color chart 60, and the correction target may be anything.

(5) Modification:
FIG. 16 shows a color chart 160 according to a modification. In the figure, the sample region is not formed. As described above, the color of the condition evaluation color patch varies depending on the printing paper. However, since the printing paper used when creating the color conversion LUT in the printer manufacturing process is determined in advance, it can be considered that the color of the color patch for condition evaluation does not substantially change in such a case. . Therefore, the sample area may not be formed in the printer manufacturing process. In addition, since the other printing conditions are fixed to some extent, the number of items of the printing conditions described in the header area can be reduced. Even when the sample region is not formed, the processing flow shown in FIG. 13 can be applied. That is, since the sample region is not recognized from the beginning in step S235 and steps S270 to S295 are executed, the process flow shown in FIG. 13 may be applied as it is.

It is a schematic block diagram of the color chart evaluation system concerning this embodiment. It is a schematic block diagram of the color chart printing apparatus concerning this embodiment. 1 is a schematic configuration diagram of a color chart color measurement device according to an embodiment. It is the flowchart which showed the content of the color chart printing process. It is a table listing printing conditions. It is a figure which shows UI screen. It is the flowchart which showed the content of the header area data creation process. It is a table | surface which shows a code list. It is a table | surface which shows the printing conditions made into the character string. It is a table | surface which shows a color specific table. It is a figure which shows arrangement | positioning of the patch data in a header area | region. It is a figure which shows a color chart. It is the flowchart which showed the content of the color chart evaluation process. It is a table | surface which shows a character specific table. It is a figure which shows a sample mounting table. It is a figure which shows the color chart concerning a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Computer, 15 ... HDD, 17 ... Color evaluation area data, 18 ... Color conversion LUT, 19 ... Code list, 20a, 80a ... Timer, 21 ... Printer driver, 21a ... Print condition setting module, 21b ... Print condition acquisition module , 21c ... Character string conversion module, 21d ... Header area data creation module, 21e ... Image composition module, 21i ... Correction module, 31 ... Keyboard, 32 ... Mouse, 33 ... Display, 40 (40a) ... Printer, 50 ... Colorimetry Machine, 60, 160 ... color chart, 70 ... computer, 75a ... reference value, 75b ... code list, 75c ... character identification table, 75d ... sample arrangement table, 81 ... evaluation program, 81a ... correction data creation module, 81b ... color Evaluation module, 81c ... Decoding module , 81d ... character identification module, 82 ... colorimeter driver, 90 ... correction data

Claims (6)

A color chart printing apparatus for forming a color chart in which a plurality of color patches formed with colors in a predetermined area are distributed on a recording medium, and the color chart by measuring each color patch of the color chart In a color chart evaluation system comprising a color chart colorimetry device for evaluating
The color chart printing apparatus is
Condition acquisition means for acquiring the formation conditions of the color chart;
A character string converting means for expressing the formation condition acquired by the condition acquiring means by a combination of a plurality of characters;
Color specifying means for specifying a color corresponding to the character;
A condition evaluation color patch including a sample region in which the color patches having colors corresponding to the characters that can be used by the color specifying means are arranged, and a color evaluation color patch to which a sample color is attached are recorded on the recording medium. Color patch forming means to be formed on;
And having
The color chart colorimetric device is
The character specification table that defines the correspondence between the character and the color value of the color corresponding to the character is referred to, and the character specification table described by the color measurement value of the condition evaluation color patch in the sample area Character specifying means for updating the color value and specifying the character corresponding to the colorimetric value obtained by measuring the color patch for condition evaluation;
Decoding means for decoding the formation condition based on the character specified by the character specifying means and an array of each condition evaluation color patch;
Color evaluation means for evaluating the color patches for color evaluation based on the formation conditions decoded by the decoding means;
A color chart evaluation system comprising:   When the color difference between the color value described in the character specification table and the colorimetric value obtained by measuring the color patch for condition evaluation is within a predetermined allowable range, the character specifying unit is The color chart evaluation system according to claim 1, wherein the color patch for condition evaluation that has been measured is determined to correspond to the character associated with the color value.   2. The character specifying means narrows the allowable range when updating the color value described in the character specifying table with a colorimetric value of the condition evaluation color patch in the sample area. The color chart evaluation system described in 1. In a color chart colorimetry device for evaluating a color chart in which a plurality of color patches formed by adding colors in a predetermined area are distributed on a recording medium,
Condition evaluation including a sample region in which a color associated with a character that can express the formation conditions of the color chart by being combined is attached and the color patch having a color corresponding to the character that can be used is arranged A colorimetric means for measuring the color patch,
The character specification table that defines the correspondence between the character and the color value of the color corresponding to the character is referred to, and the character specification table described by the color measurement value of the condition evaluation color patch in the sample area Character specifying means for updating the color value and specifying the character corresponding to the color measurement value of each condition evaluation color patch acquired by the color measurement means;
Decoding means for decoding the formation condition based on the character specified by the character specifying means and an array of each condition evaluation color patch;
A color chart colorimetric apparatus comprising: color evaluation means for evaluating the color patch for color evaluation based on the formation conditions decoded by the decoding means. A color chart printing step for forming a color chart in which a plurality of color patches formed by coloring a predetermined area are distributed on a recording medium, and the color chart by measuring each color patch of the color chart In a color chart evaluation method comprising a color chart colorimetric process for evaluating
The color chart printing process
A condition acquisition step of acquiring the formation conditions of the color chart;
A characterizing step for expressing the formation condition acquired in the condition acquiring step by a combination of a plurality of characters;
A color specifying step for specifying a color corresponding to the character;
A condition evaluation color patch including a sample area in which the color patches having colors corresponding to the characters that can be used in the color specifying step are arranged, and a color evaluation color patch to which a sample color is attached are recorded on the recording medium. And a color patch forming process formed on the top,
The color chart colorimetry process is as follows:
The character specification table that defines the correspondence between the character and the color value of the color corresponding to the character is referred to, and the character specification table described by the color measurement value of the condition evaluation color patch in the sample area A character specifying manual step for updating the color value and specifying the character corresponding to the colorimetric value obtained by measuring the color patch for condition evaluation;
A decoding step of decoding the formation conditions based on the characters specified in the character specification step and an array of each condition evaluation color patch;
A color chart evaluation method comprising: a color evaluation step for evaluating the color patch for color evaluation based on the formation conditions decoded in the decoding step. In a color chart colorimetry method for evaluating a color chart in which a plurality of color patches formed with colors in a predetermined area are distributed on a recording medium,
Condition evaluation including a sample region in which a color associated with a character that can express the formation conditions of the color chart by being combined is attached and the color patch having a color corresponding to the character that can be used is arranged A colorimetry process for colorimetric color patches;
The character specification table that defines the correspondence between the character and the color value of the color corresponding to the character is referred to, and the character specification table described by the color measurement value of the condition evaluation color patch in the sample area A character specifying step of updating the color value and specifying the character corresponding to the colorimetric value of each condition evaluation color patch acquired in the colorimetric step;
A decoding step of decoding the formation conditions based on the characters specified in the character specification step and an array of each condition evaluation color patch;
A color chart colorimetric method comprising: a color evaluation step for evaluating the color patch for color evaluation based on the formation conditions decoded in the decoding step.

Images