JP2012222501A - Image processing device, lookup table creation method, printing device, image processing method and image processing program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique relating to image processing of image data.SOLUTION: An image processing device for processing image data converts color component values of respective image data corresponding to a color development region and a special glossy region using one media profile prepared to reproduce the color of the color development region on a predetermined printing medium into an adjusted color development region color component value and an adjusted special glossy region color component value respectively; converts the adjusted color development region color component value to an ink amount set that is a combination of ink amounts of each ink using a lookup table for a color prepared to reproduce the color of the color development region by colors of ink of a printing device; and converts the adjusted special glossy region color component value to the ink amount set using a lookup table for special gloss prepared to reproduce at least a color phase of the special glossy region by colors of ink of the printing device.

Description

  The present invention relates to an image processing apparatus, and more particularly, to a technique of an image processing apparatus that outputs image data for printing subjected to image processing to a printing apparatus including color ink and special glossy ink having special gloss.

  For example, printing is performed using color inks such as cyan (C), magenta (M), yellow (Y), and black (K) and inks of special glossy colors (for example, metallic luster and pearl white). A technique for performing is known (for example, Patent Document 1). When such printing is performed, an area expressed only with color ink (hereinafter also referred to as a color coloring area) and an area expressed using color ink and a special glossy color (hereinafter also referred to as a special gloss area). ), The amount of color ink used in each region is different even when the same color value is expressed. Therefore, a look-up table (hereinafter also referred to as LUT) used in the color conversion process performed as one of the printing processes is a gradation value (hereinafter also referred to as a color component value) of each color component in the color development region of the print target image. LUT (hereinafter also referred to as C-LUT) used to convert the color component value of the special color area into the ink amount set (hereinafter referred to as S-LUT). ) And two.

  By the way, when printing is performed, in order to reproduce the original color of an image to be printed on a predetermined print medium, conversion is performed to increase / decrease each color component value using a media profile for the image data. When printing using the special glossy color ink described above, it is necessary to prepare media profiles that match the characteristics of each LUT for each of the C-LUT and S-LUT. Therefore, when color conversion processing is performed, a problem has been pointed out that a storage area must be largely secured in order to store two media profiles.

JP 2010-52225 A

  Based on the above problems, the problem to be solved by the present invention is to reduce the storage capacity reserved for the media profile used when printing using special glossy colors.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
An image processing apparatus that outputs image data for printing that has undergone image processing to a printing apparatus that performs printing using color ink and special glossy ink having special gloss, and color development expressed by a combination of basic colors An input unit for inputting image data representing an image to be printed including an area and a special gloss area expressed using special gloss, and a color development area prepared for reproducing the color of the color development area on a predetermined print medium. Using one media profile, the color component values of the image data corresponding to the color development area and the special gloss area are respectively converted into an adjustment color development area color component value and an adjustment special gloss area color component value. A media profile conversion module for converting, and a color coloring area prepared for reproducing the color of the color development area with the ink color of the ink provided in the printing apparatus; Using a color look-up table, a color development area color conversion module that converts the adjusted color development area color component value into an ink quantity set that is a combination of the ink quantities of each ink, and at least the hue of the special glossy area A special gloss area color conversion module that converts an adjusted special gloss area color component value into the ink amount set using a special gloss look-up table prepared to reproduce the ink color of the ink included in the printing apparatus; An image processing apparatus comprising:

  According to this image processing apparatus, when each color component value corresponding to the color development area and the special gloss area is converted into the adjustment color development area color component value and the adjustment special gloss area color component value, respectively, one media profile is used. As a result, the storage capacity reserved for reading the media profile can be reduced. Furthermore, at least the hue of the special glossy area of the image to be printed can be reproduced with the ink color of the ink provided in the printing apparatus. The special gloss means a special gloss texture such as metal gloss or pearl white, and the special gloss ink is an ink used for expressing the special gloss in a printed image after printing.

[Application Example 2]
The image processing apparatus according to Application Example 1, wherein a hue of a color represented by the ink amount set after the special gloss area color conversion module has converted a predetermined color component value is the color development area color conversion module The ink amount set recorded at each grid point of the special gloss look-up table is adjusted so that the color hue represented by the ink amount set after converting the predetermined color component value is approximated. Image processing apparatus.

  According to this image processing apparatus, the hue can be made substantially equal when the predetermined color in the image to be printed is printed and reproduced as a color coloring area and when it is reproduced as a special glossy area.

[Application Example 3]
The image processing apparatus according to application example 1 or application example 2, wherein the special glossy area is a metallic area having a metallic gloss, and the special glossy ink is a metallic ink having a metallic gloss.

  According to this image processing apparatus, it corresponds to image data representing a print target image including a color coloring area and a metallic area.

[Application Example 4]
Special gloss that converts color component values of the special gloss image into an ink amount set that is a combination of the ink amounts of the inks in a special gloss image that can be expressed using color ink and special gloss ink having special gloss A color lookup table that converts a color component value representing a color image that can be expressed only by the color ink into the ink amount set, and a predetermined color component value is obtained using the color lookup table. Using the adjustment look-up table in which the total ink amount of the color ink is smaller than the color look-up table in the ink amount set recorded at the same grid point position and the step of converting to the first ink amount set Converting the predetermined color component value into a second ink amount set, the first ink amount set, and the second ink amount set. Based on the ink amount set, the hue of the color represented by the second ink amount set is made closer to the hue of the color represented by the first ink amount set. Adjusting the ink amount of each ink color to acquire a new second ink amount set, and updating the adjustment look-up table with the acquired new second ink amount set, for the special gloss A method of generating a special gloss look-up table.

  The special gloss look-up table generated by this generation method and the color look-up table can make the hues of the colors represented by the ink amount sets stored at the same grid point position substantially equal. .

（ｗ１≦ｗ３，ｗ２≦ｗ３）
の値が０に近づくように、前記新たな第２のインク量セットを最適化する工程とを備える特殊光沢用ルックアップテーブルの生成方法。 [Application Example 5]
The method for generating the special gloss look-up table according to Application Example 4, wherein the step of acquiring the new second ink amount set includes the first ink amount based on the first ink amount set. Calculating the lightness value L1, the saturation value C1, and the hue angle value h1 of the color represented by the set; and the second ink amount set based on the second ink amount set. Calculating the lightness value L2, the saturation value C2, and the hue angle value h2 of the represented color, and the lightness value of the color represented by the new second ink amount set by Lx When the saturation value is Cx, the hue angle value is hx, and the predetermined weighting coefficients are w1, w2, and w3,

(W1 ≦ w3, w2 ≦ w3)
And a step of optimizing the new second ink amount set so that the value of the special glossy value approaches 0.

  According to the method for generating the special gloss look-up table, each ink quantity set is evaluated as an L * C * h (lightness, saturation, hue angle) color system and is optimized. The hues of the colors represented by the ink amount sets stored at the same grid point position in the color lookup table and the color lookup table can be made substantially uniform with high accuracy.

[Application Example 6]
A printing apparatus that performs printing using color ink and special gloss ink having special gloss, and includes a color development area expressed by a combination of basic colors and a special gloss area expressed using special gloss Using the input unit for inputting image data representing an image to be printed and one media profile prepared for reproducing the color of the color development area on a predetermined print medium, the color development area and the special gloss A media profile conversion module that converts the color component value of each of the image data corresponding to the area into an adjustment color development area color component value and an adjustment special glossy area color component value, respectively, and printing the color of the color development area Use the color look-up table prepared to reproduce with the ink color of the ink provided in the device, and adjust the color development area In order to reproduce at least the hue of the special glossy area with the ink color of the ink provided in the printing apparatus, the color development area color conversion module that converts the component value into an ink amount set that is a combination of the ink amounts of the respective inks Using the prepared special gloss look-up table, a special gloss area color conversion module that converts the adjusted special gloss area color component value into the ink amount set, the color development area color conversion module, and the special gloss area color conversion And a printing unit that performs printing based on each ink amount set converted by the module.

  According to this printing apparatus, when each color component value corresponding to the color development area and the special gloss area is converted into the adjustment color development area color component value and the adjustment special gloss area color component value, respectively, one media profile is used. Therefore, the storage capacity required for reading the media profile can be reduced. In addition, at least the hue of the special gloss area of the image to be printed can be reproduced with the ink color of the ink provided in the printing apparatus.

[Application Example 7]
An image processing method for image data for printing that is output to a printing apparatus that performs printing using color ink and special gloss ink having special gloss, a color development area expressed by a combination of basic colors, and a special gloss The image data representing the image to be printed including the special glossy area expressed using the image is input, and the color of the color coloring area is reproduced using a single media profile prepared for reproduction on a predetermined printing medium. Converting the color component value of each of the image data corresponding to the color development area and the special gloss area into an adjustment color development area color component value and an adjustment special gloss area color component value, respectively. Color adjustment area color component using a color look-up table prepared to reproduce the color with the ink color of the ink provided in the printing apparatus Is converted into an ink amount set which is a combination of the ink amounts of the respective inks, and a special gloss look-up table prepared for reproducing at least the hue of the special gloss region with the ink color of the ink provided in the printing apparatus An image processing method for converting an adjusted special glossy region color component value into the ink amount set.

  According to this image processing method, when each color component value corresponding to the color development area and the special gloss area is converted into the adjustment color development area color component value and the adjustment special gloss area color component value, respectively, one media profile is used. As a result, the storage capacity required to read the media profile can be reduced. In addition, at least the hue of the special gloss area of the image to be printed can be reproduced with the ink color of the ink provided in the printing apparatus.

[Application Example 8]
An image processing program for processing image data for printing output to a printing apparatus that performs printing using color ink and special glossy ink having special gloss, and a color development area expressed by a combination of basic colors And a function for inputting image data representing an image to be printed including a special gloss area expressed using special gloss, and a function prepared for reproducing the color of the color development area on a predetermined print medium. Using the two media profiles, the color component values of the image data corresponding to the color development area and the special gloss area are converted into the adjustment color development area color component value and the adjustment special gloss area color component value, respectively. Function and color look-up table prepared to reproduce the color of the color development area with the ink color of the ink provided in the printing apparatus And a function for converting the color component value of the adjusted color development region into an ink amount set which is a combination of the ink amounts of the respective inks, and at least the hue of the special glossy region by the ink color of the ink provided in the printing apparatus. An image processing program for causing a computer to realize a function of converting an adjusted special gloss region color component value into the ink amount set using a special gloss look-up table prepared for reproduction.

  According to this image processing program, when each color component value corresponding to the color development area and the special gloss area is converted into the adjustment color development area color component value and the adjustment special gloss area color component value, respectively, one media profile is used. Since the computer does what it does, the computer can reduce the storage capacity required to read the media profile.

[Application Example 9]
An image processing apparatus for receiving image data for printing using color ink and special glossy ink having special gloss by a printing apparatus through processing by one media profile, and performing image processing, wherein the printing The image to be printed includes a color development area expressed by a combination of basic colors and a special gloss area expressed using a special gloss, and the one media profile has a color of the color development area Are prepared for reproduction on a predetermined printing medium, and the color component value of each of the image data corresponding to the color development region and the special gloss region is respectively adjusted color development region color component value and adjustment. The glossy color component value is converted into a special glossy region color component value and output to the image processing device. A color development area color conversion module that converts an adjusted color development area color component value into an ink quantity set, which is a combination of the ink quantities of the respective inks, using a color lookup table prepared for color reproduction. And using the special gloss look-up table prepared for reproducing at least the hue of the special gloss area with the ink color of the ink provided in the printing apparatus, the adjusted special gloss area color component value is set in the ink amount set. An image processing apparatus comprising a special glossy area color conversion module for conversion.

  According to this image processing apparatus, the adjusted color coloring area color component value and the adjusted special glossy area color component value processed with one media profile are appropriately processed, and the printing apparatus has the hue of the special glossy area. The adjusted special glossy area color component value can be converted into an ink amount set so that it can be reproduced with the ink color of the ink.

[Application Example 10]
An image processing apparatus that processes image data for printing to be output to a printing apparatus that performs printing using color ink and special glossy ink having special gloss, a color coloring area expressed by a combination of basic colors, An input unit for inputting image data representing the print target image including a special gloss area expressed using special gloss, and the image so that the color of the color development area is reproduced on a predetermined print medium. The media color for converting the color component value of the data into the adjusted color component value, and the adjusted color so that the color of the color development area is reproduced with the ink color of the ink included in the printing apparatus A color look-up table for converting component values into the ink amount of the ink, and ink of at least the hue of the special glossy area provided in the printing apparatus In As can be reproduced, the image processing apparatus and a lookup table for special gloss for converting the color component values the adjusted ink amount of the ink.

  According to this image processing apparatus, when each color component value corresponding to the color development area and the special gloss area is converted into the adjustment color development area color component value and the adjustment special gloss area color component value, respectively, one media profile is used. As a result, the storage capacity reserved for the media profile can be reduced.

1 is an explanatory diagram illustrating a schematic configuration of a printing system 10. FIG. 2 is a configuration diagram of a printer 200. FIG. 6 is a flowchart illustrating a flow of printing processing. It is explanatory drawing explaining the production | generation method of Mt-LUT52. It is explanatory drawing explaining the characteristic of C-LUT and Mt-LUT for adjustment.

Embodiments of the present invention will be described based on examples.
A. First embodiment:
(A1) System configuration:
FIG. 1 is an explanatory diagram illustrating a schematic configuration of a printing system 10 as a first embodiment of the present invention. The printing system 10 includes a computer 100 as a print control device and a printer 200 that actually prints an image under the control of the computer 100. The printing system 10 functions as a printing device in a broad sense as a whole.

  The computer 100 includes a CPU 20, a ROM 60, a RAM 62, and a hard disk (HDD) 64. The computer 100 is connected to a display 70, a keyboard 72, and a mouse 74 by respective cables. A predetermined operating system is installed in the computer 100, and an application program 30, a video driver 40, and a printer driver 50 operate under this operating system. The functions of these programs are stored in the ROM 60, the RAM 62, and the HDD 64, and are realized by the CPU 20 reading and executing each program from these storage areas.

  The application program 30 is a program for the user to generate an image. Image data of an image (hereinafter also referred to as a print target image) generated by the application program 30 is also referred to as image data ORG. The image data ORG has an area expressed by a combination of basic colors (hereinafter also referred to as a color development area) and an area expressed using metallic luster (hereinafter also referred to as a metallic area). The user can designate an arbitrary area of the generated image as a metallic area.

  When the user generates an image to be printed by the application program 30, the color component values in the pixel data (hereinafter also referred to as pixel data) of the image data ORG are red (R), green (G), blue ( It is recorded in the color system of B). Hereinafter, the image data ORG immediately after being generated by the user is also referred to as image data ORG (0). Each pixel data of the image data ORG (0) is provided with a channel (hereinafter also referred to as α channel) indicating whether the pixel is a pixel belonging to the color development area or a pixel belonging to the metallic area. ing.

  The application program 30 converts the color component value of each pixel of the image data ORG (0) into a print standard color (for example, Japan color) selected by the user, and the color of the image to be printed. A media profile 32 for reproduction on a print medium is read from the HDD 64 into the RAM 62 and provided. In this embodiment, the print standard color is set by the user, but may be set in advance by the application program 30. Also, SWOP (print standard color in the United States) or Euro Standard Color (print standard color in Europe) may be selectable as the print standard color. The source profile 31 has a set of (L *, a *, b *) values (hereinafter referred to as L) for a set of (R, G, B) color component values (hereinafter also referred to as RGB values). * a * b * value), and the image data ORG (0) expressed in the RGB color system is the device-independent L * a * b * color specification. When printing is performed based on the image data ORG (1) while being converted to the system image data ORG (1), the generated print image is expressed in a preset printing standard color. Each value of L *, a *, b * is determined.

  The media profile 32 is a three-dimensional lookup table that outputs a set of RGB values for a set of L * a * b * values, and is image data expressed in the L * a * b * color system. The color of the print image is reproduced on the print medium selected by the user (for example, white plain paper) while converting ORG (1) into image data ORG (2) expressed in the RGB color system. Each value of R, G, and B is determined as follows.

  The printer driver 50 converts each pixel data of the color development area into a combination (hereinafter also referred to as an ink amount set) of ink amounts of the ink color included in the printer 200 (hereinafter also referred to as color conversion). , And C-LUT 51), and LUT 52 (hereinafter also referred to as Mt-LUT 52) for converting each pixel data in the metallic area into an ink amount set of ink color provided in the printer 200. These LUTs are read from the HDD 64 to the RAM 62 and used for color conversion when the CPU 20 activates the printer driver 50 program.

  Here, the relationship between the media profile 32 and the C-LUT 51 and Mt-LUT 52 will be described. The media profile 32 is a profile generated on the assumption that it is used together with the C-LUT 51. That is, when the color component values of the pixels belonging to the color development area are converted into the ink amount set via the media profile 32 and the C-LUT 51 and printing is performed, the print target image is printed on the print medium designated by the user. The L * a * b * value input to the media profile 32 and the output RGB value are adjusted in association with each other so that the color of the image is reproduced. Further, in this embodiment, the color component values of the pixels belonging to the metallic area are also converted using the media profile 32, and then converted into an ink amount set via the Mt-LUT 52. Therefore, the Mt-LUT 52 is generated by adjusting so that the color component value of the pixel belonging to the metallic area output using the media profile 32 can be converted into an appropriate ink amount set. A method for generating the Mt-LUT 52 will be described in detail later.

  The printer driver 50 further performs a binarization process on the ink amount set after color conversion and performs a dot data generation process (hereinafter also referred to as a halftone process), and the generated dot data. An interlace module 54 that performs processing for rearranging in the order in which the printer 200 performs printing is provided.

  The halftone module 53 uses a dither matrix (not shown) prepared in advance by the printer driver 50, and is a halftone that represents image data ORG (3) that is color-converted and represented by an ink amount set by dot distribution. Processing is performed to generate dot data. The interlace module 54 rearranges the dot arrangement of the generated dot data in the order to be transferred to the printer 200 and outputs the print data to the printer 200 as well as various commands such as a print start command and a print end command. Is output to the printer 200 to control the printer 200.

  FIG. 2 is a configuration diagram of the printer 200. As shown in FIG. 2, the printer 200 is mounted on the carriage 240, a mechanism for transporting the print medium P by the paper feed motor 235, a mechanism for reciprocating the carriage 240 in the axial direction of the platen 236 by the carriage motor 230. It comprises a mechanism for driving the print head 260 to eject ink and forming dots, and a control circuit 220 that controls the exchange of signals with the paper feed motor 235, the carriage motor 230, the print head 260 and the operation panel 225. ing.

  The mechanism for reciprocating the carriage 240 in the axial direction of the platen 236 is an endless drive between the carriage motor 230 and a slide shaft 233 that is installed in parallel with the platen 236 axis and slidably holds the carriage 240. A pulley 232 or the like that stretches the belt 231 is used.

  The carriage 240 has metallic ink (hereinafter referred to as “metallic ink”) in addition to C (cyan), M (magenta), Y (yellow), K (black), Lc (light cyan), and Lm (light magenta) color inks. Ink cartridges 241 to 247 each containing a total of seven colors of ink are mounted. The print head 260 below the carriage 240 is formed with five types of nozzle rows 261 to 267 corresponding to the above-described inks of the respective colors. Each nozzle is provided with a piezo element, and the control circuit 220 controls the contraction movement of the piezo element, so that the printer 200 can form dots for each ink color.

  When the ink cartridges 241 to 247 are mounted on the carriage 240 from above, ink can be supplied from the cartridges to the nozzle rows 261 to 267. In this embodiment, the ink cartridges 241 to 247 are arranged in the order of C, M, Y, K, Lc, Lm, and Mt in the main scanning direction of the carriage 240 as shown in FIG.

  In addition, in the case where printing (hereinafter also referred to as Mt printing) is performed in combination with metallic ink (Mt) in addition to color ink (C, M, Y, K, Lc, Lm), as shown in FIG. Printing is performed using the latter half of the nozzle rows 261 to 266 that discharge color ink in the sub-scanning direction and the first half of the nozzle row 267 that discharges metallic ink in the sub-scanning direction. In this way, by using each nozzle row, the metallic ink (Mt) dots are first formed on the print medium P, and the color ink dots are formed on the metallic ink (Mt). It can be expressed by a printed image.

  The control circuit 220 of the printer 200 is configured by connecting a CPU, ROM, RAM, PIF (peripheral device interface) and the like via a bus, and controls operations of the carriage motor 230 and the paper feed motor 235. The main scanning operation and the sub scanning operation of the carriage 240 are controlled. When the print data output from the computer 100 is received via the PIF, the control circuit 220 supplies a drive signal corresponding to the print data to the print head 260 in accordance with the main scanning or sub scanning movement of the carriage 240. In addition, each color head can be driven. The print data output from the computer 100 includes data relating to the ink colors of seven colors (C, M, Y, K, Lc, Lm, Mt) as data relating to the colors. Receive print data including data about color.

  The printer 200 having the above hardware configuration drives the carriage motor 230 to reciprocate the print head 260 (nozzle rows 261 to 267 for each color) in the main scanning direction with respect to the print medium P. By driving the paper feed motor 235, the print medium P is moved in the sub-scanning direction. The control circuit 220 prints by driving the nozzles at an appropriate timing based on the print data in accordance with the movement of the carriage 240 reciprocally (main scanning) and the movement of paper feeding of the printing medium (sub scanning). Ink dots of appropriate colors are formed at appropriate positions on the medium P. In this way, the printer 200 can print an image on the print medium P. In the above-described configuration, each color ink is stored in a detachable cartridge mounted on the printer 200. However, the ink is stored in an ink storage tank configured separately from the printer 200, and the storage tank. And the printer 200 may be connected. Or you may accommodate in the storage container comprised integrally with the printer 200 so that attachment or detachment is impossible.

(A2) Printing process:
FIG. 3 is a flowchart illustrating the flow of printing processing performed by the CPU 102 in the printing system 10. The printing process will be described with reference to FIGS. The printing process is started when the user instructs printing on the application program 30.

  When the printing process is started, the CPU 102 uses the source profile 31 as the application program 30 to convert the image data ORG (0) expressed in the RGB color system to the L * a * b * color specification. Conversion into image data ORG (1) expressed in the system (FIG. 3: step S102). Specifically, L * a * b * adjusted so that the color of the print image obtained by printing the image based on the image data ORG (1) is expressed by the print standard color set by the user. Convert to value.

  After the conversion by the source profile 31, the CPU 102 uses the media profile 32 to convert the image data ORG (1) expressed in the L * a * b * color system to the image data expressed in the RGB color system. Conversion to ORG (2) (step S104). Specifically, the color of the image of the image data ORG (2) is converted into RGB color component values adjusted to be reproduced on the print medium selected by the user.

  The CPU 102 obtains the image data ORG (2) as a function of the printer driver 50 after converting it into the image data ORG (2) expressed in the RGB color system by the media profile 32 (step S106). Based on the α channel, it is determined whether a pixel to be processed (hereinafter also referred to as a target pixel) is a pixel belonging to the color development region or a pixel belonging to the metallic region (step S110). When the pixel of interest is a pixel in the color development region, the CPU 102 uses the C-LUT 51 to set the RGB color component values of the pixel data to C, M, Y, K, Lc, and Lm ink amount sets provided in the printer 200. The color is converted to (Step S112). On the other hand, if the target pixel n is a metallic region in step S110, the CPU 102 uses the Mt-LUT 52 to obtain the RGB gradation values of the pixel data for each of the C, M, Y, and K inks provided in the printer 200. In addition, color conversion is performed to an ink amount set including metallic ink (Mt) (step S114). In the image data ORG (2), the color component value of the pixel data of the pixel belonging to the color coloring area corresponds to the adjusted color coloring area color component value described in the claims, and the pixel data of the pixel belonging to the metallic area Corresponds to the adjusted special glossy area color component value described in the claims. The C-LUT 51 corresponds to the color look-up table described in the claims, and the Mt-LUT 52 corresponds to the special gloss look-up table described in the claims.

  Thus, after the image data ORG (2) is converted into ink amount set data (hereinafter also referred to as ink amount data or image data ORG (3)) of the ink included in the printer 200, half the ink amount data is obtained. Tone processing (step S116) and interlace processing (step S118) are performed, and printing is executed in the printer 200 (step S120). In this way, the printing system 10 performs a printing process.

(A3) Method for generating Mt-LUT 52:
Next, a method for generating the Mt-LUT 52 and its characteristics will be described. FIG. 4 is an explanatory diagram for explaining a method of generating the Mt-LUT 52. The Mt-LUT 52 is generated by optimizing an existing lookup table (also referred to as an adjustment Mt-LUT 55) that converts RGB color component values into CMYKMt ink amount sets. When performing optimization, an adjustment Mt-LUT 55 and a C-LUT 51 to be incorporated in the printer driver 50 are prepared in advance.

  Here, the characteristics of the C-LUT 51 and the adjustment Mt-LUT 55 will be described. FIG. 5A is an explanatory diagram illustrating the characteristics of the C-LUT 51 by taking the ink amounts of cyan (C) and light cyan (Lc) as examples. As shown in FIG. 5A, the C-LUT 51 uses a dark color ink (cyan (C) in FIG. 5A) and a light color ink (FIG. 5A) for RGB color component values. Then, an ink amount set is determined using light cyan (Lc) together. For this reason, when pixel data (RGB) belonging to the color development region of the image data ORG (2) is input, light color ink (LcLm) is added to dark color ink (CMYK) by collation with the C-LUT 51. Converted to the ink amount set.

  FIG. 5B is an explanatory diagram for explaining the characteristics of the adjustment Mt-LUT 55. As shown in FIG. 5B, the adjustment Mt-LUT 55 determines an ink amount set only for dark color inks (CMYK) with respect to RGB gradation values, and as shown in FIG. 5C. Furthermore, the ink amount of the metallic ink (Mt) is uniformly determined (for example, 90) at each lattice point in the adjustment Mt-LUT 55. For this reason, if pixel data (RGB) belonging to the color development area of the image data ORG (2) is input, it is converted into an ink amount of dark color ink (CMYK) by collation with the adjustment Mt-LUT55. At the same time, the metallic ink (Mt) is converted into the same ink amount.

  Further, when the color component values in the RGB format are the same between the C-LUT 51 and the adjustment Mt-LUT 55, the total amount of color ink converted by each LUT is the same as that of the adjustment Mt-LUT 55. Is set to be less. This is due to the knowledge that the metallic area can achieve color development with a small amount of color ink compared to the color development area (see Japanese Patent Application Laid-Open No. 2010-52225).

  The description returns to the method of generating the Mt-LUT 52 (FIG. 4). After the C-LUT 51 and the adjustment Mt-LUT 55 described above are prepared, color component values (R1, G1, B1) in a predetermined RGB format are input to both LUTs and converted into ink amount sets. From the C-LUT 51, an ink amount set of color inks of CMYKLcLm (hereinafter also referred to as a color developing region ink amount set Ic [CMYKLcLm]) is output. The adjustment Mt-LUT 55 outputs an ink amount set including the ink amount of the metallic ink (Mt) in addition to the ink amount of the CMYK color ink (hereinafter also referred to as a metallic region ink amount set Im [CMYKMt]). The

  In this way, after the same RGB color component values are converted into ink amount sets by each LUT, among the ink colors C, M, Y, K, and Mt of the ink amount set Im [CMYKMt] for the metallic region, C, By adjusting the respective ink amounts of M, Y, and K, the hue of the printed image when printing is performed using the adjusted metallic region ink amount set Im [CMYKMt], the color coloring region ink amount set Ic [ CMYKLcLm] is adjusted so as to approach the hue of the printed image when printing is performed. The adjustment method will be specifically described below.

  First, the spectral reflectance when printing is performed with the color amount ink amount Ic set [CMYKLcLm] output by the C-LUT 51 is predicted using the color prediction model MDc for the color color region, and predicted spectral reflection is performed. The rate is acquired (see FIG. 4). The color prediction model MDc predicts a spectral reflectance R (λc) when printing is performed with an ink amount set (Cx, Mx, Yx, Kx, Lcx, Lmx) of an arbitrary color ink used in the printer 200. It is a prediction model predicted as spectral reflectance Rs (λc). The color prediction model MDc uses a spectral reflectance database obtained by actually printing color patches for a plurality of representative points in the ink amount space and measuring the spectral reflectance R (λc) with a spectral reflectometer, When printing is performed with an arbitrary ink amount set (Cx, Mx, Yx, Kx, Lcx, Lmx) by performing prediction based on a Cellular Yule-Nielsen Spectral Neugebauer Model The predicted spectral reflectance Rs (λc) is accurately obtained.

  After obtaining the predicted spectral reflectance Rs (λc) based on the color amount ink amount set Ic [CMYKLcLm], L * (lightness) and C * (saturation) corresponding to the obtained predicted spectral reflectance Rs (λc) ) And h (hue angle). Specifically, by calculating the tristimulus values X, Y, Z based on the predicted spectral reflectance Rs (λc), and converting the calculated tristimulus values X, Y, Z by a predetermined conversion formula, L * a * b * values as color values can be obtained. Then, color system conversion is performed on the acquired L * a * b * values, and L * C * h values (L1, C1, h1) are acquired.

  On the other hand, the adjustment Mt-LUT 55 is obtained from the gradation value (R1, G1, B1) by the same method as the method of obtaining the L * C * h value from the color component value (R1, G1, B1) via the C-LUT 51. Is predicted using the color prediction model MDm for the metallic region by using the ink amount set Im [CMYKMt] for the metallic region converted using, and the predicted spectral reflectance is obtained. The color prediction model MDm is a spectral reflectance R (λm) when printing is performed with an ink amount set (Cx, Mx, Yx, Kx, Mtx) of an arbitrary color ink and metallic ink used in the printer 200. It is a prediction model predicted as the predicted spectral reflectance Rs (λm). The color prediction model MDm is also a model generated by the same method as the color prediction model MDc, and the predicted spectral reflectance Rs when printing is performed with an arbitrary ink amount set (Cx, Mx, Yx, Kx, Mtx). (Λm) is obtained. Thereafter, the L * C * h value (L2, C2, h2) is calculated based on the predicted spectral reflectance Rs (λm) by the same method as the method for obtaining the L * C * h value (L1, C1, h1). To get.

  When the L * C * h value (L1, C1, h1) and the L * C * h value (L2, C2, h2) are obtained in this way, printing is performed with the color amount ink amount set Ic [CMYKLcLm]. The ink amount set for the metallic area adjusted so as to approach the hue in the case where the image processing is performed is defined as an adjusted ink amount set for the metallic area Imx [CMYKMt], and the L * C * h value corresponding to the ink amount set is further defined. Is defined as (Lx, Cx, hx). Then, an adjusted metallic area ink amount set Imx [CMYKMt] is calculated for an L * C * h value (Lx, Cx, hx) that approximates the value of τ in the following equation (1) to 0 (zero).

（ｗ１≦ｗ３，ｗ２≦ｗ３）

(W1 ≦ w3, w2 ≦ w3)

  In equation (1), w1, w2, and w3 are weighting coefficients. In this embodiment, the calculation is performed with w1 = 0.5, w2 = 0.5, and w3 = 1.0. In other words, this means that the adjusted metallic area ink amount set Imx [CMYKMt] is calculated with emphasis on the value of (Lx, Cx, hx), particularly the hue (hx) being close to h1. Of course, other values may be adopted as the values of w1, w2, and w3 within the limit of w1 ≦ w3 and w2 ≦ w3. As a specific calculation method, an adjusted ink amount set Imx for the metallic area is obtained by gradually increasing or decreasing each of the C, M, Y, and K ink amounts of the metallic area ink amount set Im [CMYKMt]. The color prediction model MDm and the color system conversion (L * a * b * → L * C * h) are performed on the basis of the adjusted metallic area ink amount set Imx [CMYKMt]. * A specific value of the C * h value (Lx, Cx, hx) is calculated. Then, the calculated value of L * C * h (Lx, Cx, hx) is substituted into equation (1) to calculate the value of τ. This process is performed a plurality of times in the combination of the adjusted metallic region ink amount set Imx [CMYKMt] in which the ink amounts of C, M, Y, and K are variously changed, and the adjusted metallic material when the value of τ is smallest is obtained. The adjustment Mt-LUT 55 is updated as an ink amount set for storing the region ink amount set Imx [CMYKMt] at the grid points of the color component values (R1, G1, B1).

  A series of steps performed on the color component values (R1, G1, B1) are performed on the RGB values corresponding to all the grid points of the adjustment Mt-LUT 55, and the ink amount set is updated at all the grid points. . The LUT after updating in this way is set as Mt-LUT 52. In the Mt-LUT 52 generated in this way, the hue of the color represented by the ink amount set stored at each grid point is stored in the C-LUT 51 at the same grid point position (R, G, B). It has a characteristic that it is substantially equal to the hue of the color represented by the ink amount set. In this way, the Mt-LUT 52 is generated.

  As described above, in the printing system 10, when converting each color component value corresponding to the color development area and the metallic area in the image data ORG by the media profile, the conversion is performed by one media profile (media profile 32). Therefore, the storage capacity reserved for reading the media profile can be reduced.

  Further, the ink amount set stored in each grid point of the Mt-LUT 52 is represented by the ink amount set in which the hue of the color represented by the ink amount set is stored at the same grid point position in the C-LUT 51. It is adjusted to be approximately equal to the hue of the color to be generated. Therefore, when an area expressed in a predetermined color in the image to be printed is printed in both the color development area and the metallic area, the hues in the two areas in the print image can be made substantially equal. Further, by adjusting the ink amount set of the Mt-LUT 52, the existing media profile 32 generated for the color development area can be used as it is as the media profile.

  As a method of generating the Mt-LUT 52, when the adjustment Mt-LUT 55 is optimized, each ink amount set is evaluated as an L * C * h color system, and thus the Mt-LUT 52 is optimized. And the hue of the color represented by the ink amount set stored at the same grid point position in the C-LUT 51 can be made substantially uniform with high accuracy.

B. 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.
(B1) Modification 1:
In the above embodiment, as the method for generating the Mt-LUT 52, when the adjustment Mt-LUT 55 is optimized, each ink amount set is evaluated as an L * C * h color system and optimized. Without being limited thereto, in the color space of the L * a * b * color system, the hue of the adjusted metallic region ink amount set Imx [CMYKMt] is brought close to the color developing region ink amount set Ic [CMYKLcLm]. For example, the evaluation and optimization may be performed in a color space other than the L * C * h color system. For example, when optimization is performed in the color space of the L * a * b * color system, each ink amount of the adjusted metallic region ink amount set Imx [CMYKMt] is changed, and the changed ink is changed. The L * a * b * points (Lx, ax, bx) corresponding to the quantity set are actually plotted in the coordinates of the L * a * b * space. Then, after the adjustment corresponding to the point (Lx, ax, bx) closest to the coordinate point in the L * a * b * space corresponding to the color amount ink amount set Ic [CMYKLcLm] that is the target of optimization. The adjustment Mt-LUT 55 is updated using the metallic area ink amount set Imx [CMYKMt]. Thus, for example, when the adjustment Mt-LUT 55 is optimized in the color space of the L * a * b * color system, in the process of generating the Mt-LUT 52 (see FIG. 4), L * C * The step of converting the color system to the color system of h can be omitted.

  As another method for generating the Mt-LUT 52, a color patch is actually printed on a print medium with a plurality of types of adjusted metallic region ink amount sets Imx [CMYKMt]. Further, the color patch of the color development area ink amount set Ic [CMYKLcLm], which is the target of optimization, is printed. Then, both color patches are actually measured, and the adjusted metallic region ink amount set Imx [CMYKMt] that is closest to the hue of the color patch of the color developing region ink amount set Ic [CMYKLcLm] is adopted, and the adjustment Mt The Lt 55 may be optimized to generate the Mt-LUT 52. When this generation method is adopted, steps such as prediction of spectral reflectance using the MDc color prediction model MDc and the color prediction model MDm, and color system conversion can be omitted.

(B2) Modification 2:
In the above-described embodiments, the metallic glossy metal glossy is used as the special glossy ink. However, the special glossy ink may be a pearl white ink having a pearl white texture, or a transparent or translucent clear ink expressing gloss. It is also possible to employ special glossy inks such as By employing these inks, various textures can be expressed as a printed image.

(B3) Change Example 3:
In the above embodiment, the ink amount of the metallic ink (Mt) is stored at each lattice point of the Mt-LUT 52. However, the ink amount of the metallic ink is not limited to this, and each lattice point of the Mt-LUT 52 is Instead of storing, the ink amount of metallic ink (Mt) may be determined separately in advance.

  In the above embodiment, the ink amount of the metallic ink (Mt) is constant, but may be variable. For example, the printing system 10 sets a one-dimensional lookup table in which the intensity of metallic feeling is set for each designated metallic area using the application program 30 and the intensity and the ink amount of metallic ink are associated with each other. It can be realized by providing it separately.

(B4) Modification 4:
In the above embodiment, a part or all of the functions (modules) performed by the CPU 102 as the application program 30 and the printer driver 50 may be performed by a RIP (Raster image processor) as software installed in the computer 100. RIP as hardware connected to the computer 100 and the printer 200 may be performed.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to such embodiment, Of course, in the range which does not deviate from the summary of this invention, it can implement in a various aspect. For example, the present invention is not limited to the serial ink jet printer shown in the above-described embodiment, but can also be applied to an ink jet line printer or a laser printer including a special glossy color toner. In addition to the configuration as a printing apparatus, the present invention can be realized as a printing method, a program, a storage medium, and the like.

10 ... Printing system 20 ... CPU
30 ... Application program 31 ... Source profile 32 ... Media profile 40 ... Video driver 50 ... Printer driver 53 ... Halftone module 54 ... Interlace module 70 ... Display 72 ... Keyboard 74 ... Mouse 100 ... Computer 102 ... CPU
DESCRIPTION OF SYMBOLS 200 ... Printer 220 ... Control circuit 225 ... Operation panel 230 ... Carriage motor 231 ... Drive belt 232 ... Pulley 233 ... Sliding shaft 235 ... Motor 236 ... Platen 240 ... Carriage 241 ... Ink cartridge 260 ... Print head 261-267 ... Nozzle row P: Print medium n: Pixel of interest ORG, ORG (0) to ORG (3): Image data MDc: Color prediction model MDm: Color prediction model

Claims (10)

An image processing apparatus that outputs image data for printing subjected to image processing to a printing apparatus that performs printing using color ink and special glossy ink having special gloss,
An input unit for inputting image data representing an image to be printed including a color development area expressed by a combination of basic colors and a special gloss area expressed using special gloss;
Using one media profile prepared for reproducing the color of the color development area on a predetermined print medium, the color component value of each of the image data corresponding to the color development area and the special glossy area is obtained. , Respectively, a media profile conversion module for converting into an adjustment color development area color component value and an adjustment special gloss area color component value;
Using a color look-up table prepared for reproducing the color of the color development area with the ink color of the ink provided in the printing apparatus, the adjustment color development area color component value is combined with the ink amount of each ink. A color development area color conversion module that converts the ink amount set to
Using the special gloss look-up table prepared for reproducing at least the hue of the special gloss area with the ink color of the ink included in the printing apparatus, the adjusted special gloss area color component value is converted into the ink amount set. Special glossy area color conversion module,
An image processing apparatus comprising: The image processing apparatus according to claim 1,
The hue of the color represented by the ink amount set after the special gloss area color conversion module has converted a predetermined color component value is the color hue after the color development area color conversion module has converted the predetermined color component value. An image processing apparatus in which the ink amount set recorded at each lattice point of the special gloss look-up table is adjusted so as to approach the hue of the color represented by the ink amount set. The image processing apparatus according to claim 1 or 2,
The special gloss area is a metallic area having a metallic luster,
The image processing apparatus, wherein the special glossy ink is a metallic ink having a metallic gloss. Special gloss that converts color component values of the special gloss image into an ink amount set that is a combination of the ink amounts of the inks in a special gloss image that can be expressed using color ink and special gloss ink having special gloss A lookup table generation method for
Converting a predetermined color component value into a first ink amount set using a color lookup table for converting a color component value representing a color image that can be expressed only with the color ink into the ink amount set; ,
Using the adjustment look-up table in which the total ink amount of the color inks is smaller than the color look-up table in the ink amount set recorded at the same grid point position, the predetermined color component value is set to the second color component value. Converting to an ink amount set;
Based on the first ink amount set and the second ink amount set, the hue of the color represented by the second ink amount set is changed to the hue of the color represented by the first ink amount set. Adjusting the ink amount of each ink color of the second ink amount set so as to be close to, and obtaining a new second ink amount set;
Updating the adjustment look-up table with the acquired new second ink amount set to obtain the special gloss look-up table. A method for generating a special gloss look-up table according to claim 4,
The step of acquiring the new second ink amount set includes:
Calculating a lightness value L1, a saturation value C1, and a hue angle value h1 of the color represented by the first ink amount set based on the first ink amount set;
Calculating a lightness value L2, a saturation value C2, and a hue angle value h2 of the color represented by the second ink amount set based on the second ink amount set;
When the lightness value of the color represented by the new second ink amount set is Lx, the saturation value is Cx, the hue angle value is hx, and the predetermined weighting factors are w1, w2, and w3 In addition,

(W1 ≦ w3, w2 ≦ w3)
And a step of optimizing the new second ink amount set so that the value of the value approaches 0, a method for generating a special gloss look-up table. A printing apparatus that performs printing using color ink and special gloss ink having special gloss,
An input unit for inputting image data representing an image to be printed including a color development area expressed by a combination of basic colors and a special gloss area expressed using special gloss;
Using one media profile prepared for reproducing the color of the color development area on a predetermined print medium, the color component value of each of the image data corresponding to the color development area and the special glossy area is obtained. , Respectively, a media profile conversion module for converting into an adjustment color development area color component value and an adjustment special gloss area color component value;
Using a color look-up table prepared for reproducing the color of the color development area with the ink color of the ink provided in the printing apparatus, the adjustment color development area color component value is combined with the ink amount of each ink. A color development area color conversion module that converts the ink amount set to
Using the special gloss look-up table prepared for reproducing at least the hue of the special gloss area with the ink color of the ink included in the printing apparatus, the adjusted special gloss area color component value is converted into the ink amount set. Special glossy area color conversion module,
A printing apparatus comprising: a printing unit that performs printing based on each of the ink amount sets converted by the color coloring area color conversion module and the special glossy area color conversion module. An image processing method for printing image data to be output to a printing apparatus that performs printing using color ink and special gloss ink having special gloss,
Input image data representing the image to be printed, including a color development area expressed by a combination of basic colors and a special gloss area expressed using special gloss,
Using one media profile prepared for reproducing the color of the color development area on a predetermined print medium, the color component value of each of the image data corresponding to the color development area and the special glossy area is obtained. , Respectively, convert to the adjustment color development area color component value and adjustment special gloss area color component value,
Using a color look-up table prepared for reproducing the color of the color development area with the ink color of the ink provided in the printing apparatus, the adjustment color development area color component value is combined with the ink amount of each ink. To the ink amount set that is
Using the special gloss look-up table prepared for reproducing at least the hue of the special gloss area with the ink color of the ink included in the printing apparatus, the adjusted special gloss area color component value is converted into the ink amount set. Image processing method. An image processing program for processing image data for printing output to a printing apparatus that performs printing using color ink and special glossy ink having special gloss,
A function for inputting image data representing an image to be printed including a color development area expressed by a combination of basic colors and a special gloss area expressed using special gloss;
Using one media profile prepared for reproducing the color of the color development area on a predetermined print medium, the color component value of each of the image data corresponding to the color development area and the special glossy area is obtained. , Respectively, a function for converting to an adjustment color development area color component value and an adjustment special gloss area color component value;
Using a color look-up table prepared for reproducing the color of the color development area with the ink color of the ink provided in the printing apparatus, the adjustment color development area color component value is combined with the ink amount of each ink. A function to convert the ink amount set to
Using the special gloss look-up table prepared for reproducing at least the hue of the special gloss area with the ink color of the ink included in the printing apparatus, the adjusted special gloss area color component value is converted into the ink amount set. An image processing program that allows a computer to realize its functions. An image processing device that receives image data for printing using color ink and special glossy ink having special gloss by a printing device through processing by one media profile, and performs image processing,
The print target image for performing printing includes a color development area expressed by a combination of basic colors and a special gloss area expressed using special gloss, and the one media profile includes the color development area The color component values of the image data corresponding to the color development area and the special glossy area are respectively adjusted color development area color component values. And converted to an adjusted special glossy area color component value and output to the image processing apparatus,
Using a color look-up table prepared for reproducing the color of the color development area with the ink color of the ink provided in the printing apparatus, the adjustment color development area color component value is combined with the ink amount of each ink. A color development area color conversion module that converts the ink amount set to
Using the special gloss look-up table prepared for reproducing at least the hue of the special gloss area with the ink color of the ink included in the printing apparatus, the adjusted special gloss area color component value is converted into the ink amount set. An image processing apparatus comprising: a special glossy area color conversion module. An image processing apparatus that processes image data for printing output to a printing apparatus that performs printing using color ink and special glossy ink having special gloss,
An input unit for inputting image data representing the print target image including a color development area expressed by a combination of basic colors and a special gloss area expressed using special gloss;
One media profile for converting the color component value of the image data into an adjusted color component value so that the color of the color development region is reproduced on a predetermined print medium;
A color lookup table for converting the adjusted color component value into the ink amount of the ink so that the color of the color development region is reproduced with the ink color of the ink provided in the printing apparatus;
A special gloss look-up table for converting the adjusted color component value into the ink amount of the ink so that at least the hue of the special gloss area is reproduced with the ink color of the ink included in the printing apparatus. Image processing device.

Images