JP2005277761A - Color adjusting method, color image forming method, and color image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily adjust the output intensity of a plurality of basic colors constituting a multiple color containing inks of their single colors for adjusting the output intensity of the plurality of basic colors constituting ink single colors. <P>SOLUTION: Upon receipt of the input of a desired adjusting value about at least one of single colors respectively obtained by printing a plurality of color materials, the output intensity of a plurality of basic colors is adjusted with the inputted adjusting value about the single colors with adjusting values inputted, but the output intensity of the plurality of basic colors is adjusted, based on the inputted adjusting value, about colors composed of the single colors with adjusting value inputted and at least another color material. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a color adjustment method for matching a color to be output to a target color, a color image forming method using the color adjustment method, and a color image forming apparatus to which the color image forming method is applied. The present invention relates to an apparatus for performing color adjustment by changing the output intensity of a plurality of basic colors so as to reproduce the color of a halftone dot line portion obtained by printing each halftone image on a recording medium. .

  In recent years, with the spread of DTP (Desk Top Publishing) and the like, the work of image editing and page imposition on computer software has become common, and full digital editing has become rare.

  In these processes, aiming for further efficiency, image setter output that directly outputs image data that has undergone page editing on film, CTP (Computer to Plate) output that directly records images on a printing plate, and printing A CTC (Computer to Cylinder) for directly recording an image on a printing plate wound on a cylinder of the machine is performed.

  Moreover, in the calibration process in such a printing process, (1) confirmation of internal errors in the work site, that is, internal school, (2) external school to be submitted to the orderer and designer for confirmation of finishing, (3) printing Proofs are created and used in three main applications: a print sample provided to the captain of the machine as a sample of the final print.

  As described above, when color printing is made, color calibration is performed at the stage of the original film, so that the Y (yellow) plate, the M (magenta) plate, the C (cyan) plate, and the BK (black) plate are obtained. Produce a proof (color proof) using each color separation net original film, and make the original printing plate, the color of the original film is correct, the color is correct, and there is no character error. The printed matter was checked in advance.

  In this case, film output or printing plate output is performed only for calibration confirmation, and printing calibration or calibration with other calibration materials has the problem that waste of film and printing plate and unnecessary work increase. .

  Therefore, in particular, in a process of creating and editing a full digital image by such a computer, a system for directly outputting a color image called DDCP (Direct Digital Color Proof) or DCP (Digital Color Proof) is required. .

  Such DDCP records digital image data processed on a computer on a plate-making film with an image setter or the like, performs a final printing operation for directly producing a printing plate with CTP, or a printing machine with CTC. Create a color proof that reproduces the output object indicated by the digital image processed on the computer before recording the image directly on the printing plate wound on the cylinder, and the design, color, text, etc. This is to confirm.

  Further, as a means for creating a color proof, based on the halftone dot image data of each color separation halftone original, a light spot consisting of a plurality of lights having different wavelengths such as R, G, B, etc. is applied to a silver salt color photosensitive material. There is a color proof creation device that creates a color proof by exposing a dot image of three basic colors Y, M, and C to reproduce a halftone image. In addition, in order to reproduce the primary color (ink (coloring material) single color) of the printing machine, the multi-order color (color that overlaps the ink) obtained by overprinting the ink, and the ground color of the printing paper, There is a DDCP of a type in which a combination of output strengths of three basic colors for each of the primary color, multi-order color, and white is set in advance and output based on the setting (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2003-149996 (paragraphs [0119]-[0168], FIGS. 3 to 5)

  However, if the color output from the color proofing device must be adjusted due to changes in the printing conditions of the target printing machine, the operator configures the color of the halftone dot line portion of the single ink. The output intensity of several basic colors was updated manually. In this case, it is necessary to update the output intensity of the basic color for the multi-color including the single color ink. Furthermore, after the update, there is a case where the color proof is output again from the color proof creating apparatus to check the color, and the above update is performed again. As described above, the update operation of the color channel table is complicated and requires a lot of time and labor.

  The present invention has been made in view of the above circumstances, and the object of the present invention is to adjust the output intensity of a plurality of basic colors constituting an ink single color by using a multi-color including the single color ink. Color adjustment method capable of easily adjusting output intensity of a plurality of basic colors, color image forming method using the color adjustment method, and color image forming apparatus using the color image forming method Is to provide.

  In order to achieve the above object, according to the first aspect of the present invention, the output intensity of a plurality of basic colors is changed, and a plurality of color materials including colors and pigments of the recording medium are printed on the recording medium. A color adjustment method for reproducing a color obtained by inputting a desired adjustment value for at least one of the single colors obtained by printing each of the plurality of color materials. In response, the output intensity of the plurality of basic colors constituting the single color to which the adjustment value is input is adjusted by the input adjustment value, and the single color to which the adjustment value is input and at least one other color material The output intensities of the plurality of basic colors constituting the color constituted by the above are adjusted based on the inputted adjustment value.

  According to a second aspect of the present invention, the adjustment of the output intensity of the plurality of basic colors constituting a color composed of the single color to which the adjustment value is input and at least one other color material is performed by adjusting the color. An adjustment coefficient is obtained based on the order in which the color materials constituting the color are overprinted, and a numerical value indicating transparency or a numerical value indicating a state in which the color material rides, and the adjustment value and the adjustment coefficient are determined. It is characterized by use.

  According to a third aspect of the present invention, when the single color material to which the adjustment value is input is printed on another color material, the adjustment coefficient is a single color to which the adjustment value is input. If the color value is a numerical value indicating the state on which the material is placed and is printed on another color material on which the adjustment value has been input, the single color material to which the adjustment value is input is applied. The product of the numerical value indicating the state and the transparency of the color material printed on the single color material to which the adjustment value is input, and the single color material to which the adjustment value is input is printed immediately above the recording medium Is characterized by the transparency of the color material printed on the single color material to which the adjustment value is input.

  According to a fourth aspect of the present invention, in the case where a plurality of color materials are printed on the single color material to which the adjustment value is input, the transparency is applied to the single color material to which the adjustment value is input. It is characterized by the product of the transparency of a plurality of color materials to be overprinted.

  According to a fifth aspect of the present invention, there are provided a plurality of colors and a plurality of halftone dot line portions obtained by printing each halftone dot image of a plurality of color materials including a color of a recording medium and a pigment on the recording medium. A color image that forms a color image while reproducing the colors of the halftone line portions by changing the output intensity of the plurality of basic colors based on a color channel table showing a correspondence relationship with the combination of the output intensity of the basic colors A forming method, wherein an input of a desired adjustment value for at least one of each single color obtained by printing each of the plurality of color materials is received, and the adjustment value of the color channel table is received And updating the output intensity of the plurality of basic colors constituting the single color to which the adjustment value is input, and from the color channel table, the monochrome color material to which the adjustment value is input and Extracting the color of a halftone line portion composed of at least one other color material, and outputting the output intensity of the plurality of basic colors constituting the color of the extracted halftone line portion of the color channel table Updating based on an adjustment value and controlling to change output intensities of the plurality of basic colors based on the updated color channel table when forming the color image. It is characterized by that.

  According to a sixth aspect of the present invention, the update of the output intensity of the plurality of basic colors constituting the color of the extracted halftone line portion is a color material constituting the color of the extracted halftone line portion. The adjustment coefficient is obtained based on the order of printing and the numerical value indicating the transparency of the color material constituting the color or the numerical value indicating the state of the color material, and is calculated using the adjustment value and the adjustment coefficient. The output intensity is obtained and updated with the output intensity.

  According to a seventh aspect of the present invention, when the single color material to which the adjustment value is input is overprinted on another color material, the adjustment coefficient is a single color to which the adjustment value is input. If the color value is a numerical value indicating the state on which the material is placed and is printed on another color material on which the adjustment value has been input, the single color material to which the adjustment value is input is applied. The product of the numerical value indicating the state and the transparency of the color material printed on the single color material to which the adjustment value is input, and the single color material to which the adjustment value is input is printed immediately above the recording medium Is characterized by the transparency of the color material printed on the single color material to which the adjustment value is input.

  Further, in the invention according to claim 8, when the transparency is a plurality of color materials to be printed on the single color material to which the adjustment value is input, the transparency is applied to the single color material to which the adjustment value is input. It is characterized by the product of the transparency of a plurality of color materials to be overprinted.

  According to a ninth aspect of the present invention, there is provided a plurality of colors and a plurality of halftone dot line portions obtained by printing each halftone image of a plurality of color materials including a color of a recording medium and a pigment on the recording medium. A color image that forms a color image while reproducing the colors of the halftone line portions by changing the output intensity of the plurality of basic colors based on a color channel table showing a correspondence relationship with the combination of the output intensity of the basic colors A forming apparatus that receives an input of a desired adjustment value for at least one of each of the single colors obtained by printing each of the plurality of color materials, and the adjustment value of the color channel table And updating the output intensity of the plurality of basic colors constituting the single color to which the adjustment value is input, and from the color channel table, the monochrome color material to which the adjustment value is input and Extracting the color of a halftone line portion composed of at least one other color material, and outputting the output intensity of the plurality of basic colors constituting the color of the extracted halftone line portion of the color channel table Update means for updating based on the adjustment value; and control means for controlling to change output intensities of the plurality of basic colors based on the updated color channel table when forming the color image; It is characterized by having.

  According to the color adjustment method of claim 1, by inputting an adjustment value for a single color, the output intensity of the basic color for the single color is adjusted with the adjustment value, and the output intensity of a multi-color including the single color is adjusted. Therefore, it is possible to automatically adjust the output intensity of the basic color for the multi-order color based on the adjustment value of the output intensity of the single color.

  According to the color adjustment method of the second aspect, the order in which the color materials of multi-order colors including the single color to which the adjustment value is input is printed, the numerical value indicating the transparency set for each color material, and the state in which the color material is placed An adjustment coefficient is obtained for each multi-order color based on the numerical value, and the output intensity of the basic color of the multi-order color can be adjusted using the adjustment value of the single color to which the adjustment value is input and the obtained adjustment coefficient.

  According to the color adjustment method of the third aspect, the adjustment coefficient can be easily obtained from a numerical value indicating the transparency set for each color material and a numerical value indicating the state on which the color material rides.

  According to the color adjustment method of the fourth aspect, the adjustment coefficient can be easily obtained when a plurality of color materials are printed on the single color to which the adjustment value is input.

  According to the color image forming method of claim 5, when updating the output intensity of the basic color constituting the single color of the color channel table, it is possible to input the single color without bothering to input the output intensity of the multi-color including the single color. The color channel table can be easily updated based on the output intensity adjustment value, and the output intensity of the basic color is changed based on the updated color channel table. A color image that reproduces the color of the portion can be formed.

  According to the color image forming method of claim 6, a numerical value indicating the order in which the color materials of multi-order colors including a single color to which an adjustment value is input and the transparency set for each color material are present, and the state in which the color material is placed. It is possible to obtain an adjustment coefficient for each multi-order color based on the numerical value indicated, and update the output intensity of the basic color of the multi-order color using the adjustment value of the single color to which the adjustment value is input and the obtained adjustment coefficient. .

  According to the color image forming method of the seventh aspect, the adjustment coefficient can be easily obtained from the numerical value indicating the transparency set for each color material and the numerical value indicating the state on which the color material rides.

  According to the color image forming method of the eighth aspect, the adjustment coefficient can be easily obtained when a plurality of color materials are printed on the single color to which the adjustment value is input.

  According to the color image forming apparatus of claim 9, when updating the output intensity of the basic color constituting the single color of the color channel table, it is possible to input the single color without bothering inputting the output intensity of the multi-color including the single color. The color channel table can be easily updated based on the output intensity adjustment value, and the output intensity of the basic color is changed based on the updated color channel table. A color image that reproduces the color of the portion can be formed.

  The present invention reproduces the color of a halftone dot portion obtained by printing each halftone image of a plurality of inks (coloring materials) on a printing paper (recording medium) as a target color. The present invention relates to processing performed by changing the output intensities of a plurality of basic colors based on a color channel table (described later) indicating the correspondence between the colors of printing paper and halftone image lines and the output intensities of a plurality of basic colors.

  In addition, the L * a * b * color system value shown below is one of the color system values representing the color, and the color in the three-dimensional space of the L * axis, a * axis, and b * axis. The hue and saturation are represented by the a * b * plane, and L * is a value of a color characteristic orthogonal to the a * b * plane and representing lightness. The values of the L * a * b * color system are x-bar, y-bar defined by the CIE (Commission Internationale de l'Eclairage) as equivalent to the sensitivity of the human eye. , Z-bar spectral characteristics (predetermined spectral characteristics) based on the values of the XYZ color system obtained by integrating the amount of light.

  In the following description of the present invention, an embodiment applied to a color proof producing apparatus (color image forming apparatus) is shown as an example, and will be specifically described with reference to the drawings.

(Control configuration of color proofing device)
First, the color proof creating apparatus according to the present embodiment uses a printing press with a plurality of inks, for example, C (cyan), M (magenta), Y (yellow), and K (black) in the present embodiment. Color ink and halftone dot line color obtained by overprinting the dot images of each ink are set as the target color, and the target color is used as a plurality of basic colors in the color proof making device In the form of Y, M, and C. In some cases, the order of “C, M, Y”, “YMC”, and “CMY” may be described in a different order.) An image is output, and is suitable by applying the color adjustment method of the present invention. In particular, it works suitably when the ink contains a pigment.

  FIG. 1 shows a functional block diagram of the color proof producing apparatus. As shown in FIG. 1, the color proof creating apparatus of the present embodiment includes a control unit 1, a color channel calculation unit 2, a color table 3, a reference table 4, a color channel table 5, an image recording unit 6, an input unit 7, And a coefficient table 8. Further, details of each part will be described below.

  The color table 3 is a primary color, a secondary color, a tertiary color, or a quaternary color (hereinafter collectively referred to as CMYK1 /) printed on a printing paper using, for example, C, M, Y, and K inks on a printing machine. In some cases, it is referred to as a 2/3/4 color (details will be described later), and the values of the L * a * b * color system of the ground color of the printing paper are as shown in FIG. Is stored in. FIG. 4 also shows an example of the L * a * b * color system values of the above-mentioned CMYK1 / 2/3/4 color and the background color of the printing paper (displayed as W (white) in the figure). Show.

  Here, CMYK1 / 2/3/4 quaternary colors will be described. Primary color is a single color of CMYK ink, secondary color is a color combining two of CMYK inks, tertiary color is a color combining three of CMYK inks, and quaternary colors are CMYK inks The primary colors are C, M, Y, K, and the secondary colors are R (MY), G (CY), B (CM), KC, KM, KY, and tertiary. The colors are CMY, KR (KMY), KG (KCY), KB (KCM), and the quaternary color is KCMY, for a total of 15 colors. FIG. 2 shows a correspondence relationship between each color to be printed and ink (indicated by a black circle). Further, it is assumed that the ink is overprinted in order from the left ink in FIG. 2, that is, in order of K → C → M → Y.

  The coefficient table 8 is a storage means, and stores the transparency T and the trapping rate TR for each ink in a configuration as shown in FIG. 3, for example. The transparency T is a numerical value indicating the transparency of the ink, and is a coefficient for correcting the spectral density of the lower color when the ink is overprinted. The trapping rate TR is a coefficient for correcting the spectral density of the color on the upper side, which is a numerical value indicating whether ink is easily or not easily applied, in other words, a state where the ink is applied. In the following description, the trapping rate TR is set to each ink, and is a numerical value indicating a state in which the set ink is placed on another ink.

  If the ink is completely transparent, the transparency T is “1”. If the ink is completely opaque, the transparency T is “0”. Therefore, the transparency T is a constant between 0 and 1. Further, since the trapping rate TR is a constant between 0 and 1 because if the value with respect to the printing paper is set to 1, generally, the paste with respect to other ink drops compared to the printing paper. It depends on the ink.

  The reference table 4 defines L * a * b * → CMY, which defines the correlation with the combination of the output intensity of each basic color corresponding to the value of the L * a * b * color system as output characteristics in the image recording unit 6. The LUT is stored. This L * a * b * → CMY LUT indicates the output intensity of C, M, and Y of the image recording unit 6 (described later) as described in the specification of Japanese Patent Application No. 2003-066429 by the present applicant. A color chart in which a plurality of color images in which the respective outputs are combined with equal division between the minimum value 0 and the maximum value is arranged is output, and the L * a * b * color system values of the plurality of color images A CMY → L * a * b * LUT is created from the combination of the output intensity of C, M, and Y and the value of the L * a * b * color system at that time, and the CMY → L * Output intensity of C, M, and Y for each combination obtained by equally dividing L * (0 to 100), a *, (-127 to 128), and b * (-127 to 128) using an a * b * LUT Can be obtained by a convergence calculation process.

  Further, the color table 3, the reference table 4, and the coefficient table 8 may be incorporated from the beginning in storage means such as an HDD (Hard Disk Drive) provided in the color proof creating apparatus, for example.

  The input unit 7 includes a display unit and an operation unit. The input unit 7 performs display on the display screen of the display unit based on the screen information and performs various inputs using the display and the operation unit. The operation means composed of a touch panel for receiving and the display means composed of an LCD (liquid crystal display) for displaying patterns and characters are arranged so as to be operated and input by pressing the touch panel at the position displayed on the LCD. And so on. The input means 7 is for, for example, designating ink used for printing and printing paper, inputting an instruction for creating a color proof, and inputting related to updating the color channel table 5.

  The color channel calculation means 2 is based on L * a * b * color system values stored in the color table 3 and L * a * b * → CMY LUT stored in the reference table 4. It has the function as a production | generation means to produce | generate. For example, as described in the specification of Japanese Patent Application No. 2003-066429 by the present applicant, L * a * b * → CMY LUT input point L * a * b * is stored in the color table 3. L * a * b * color system value L * a * b * L * 2 point (L1, L2), a * 2 point (a1, a2), b * 2 point (b1) , B2) from the output intensity of C, M, Y for 8 points and the distance from each input point of L * a * b * each value of L * a * b * color system A combination of C, M, and Y output intensities with respect to the stored L * a * b * color system values can be obtained. Also, it has a function as an updating unit that receives an input from the input unit 7 and updates the color channel table 5 (details regarding the update will be described later).

  Further, in the present embodiment, it has been described that L * a * b * → CMY LUT is stored as the reference table 4, but L * a * b corresponding to the combination of the output intensities of the respective basic colors as the reference table 4. * CMY → L * a * b * LUT defining the correlation with the value of the color system may be stored. In that case, when obtaining a combination of CMY output intensities for outputting L * a * b * color system values, CMY → L * a * b * LUT to L * a * b * → CMY What is necessary is just to obtain | require LUT. Therefore, the “reference table” of the present invention includes an output intensity of a plurality of basic colors such as L * a * b * → CMY LUT and CMY → L * a * b * LUT, and L * a * b * color system. It is sufficient if it shows the correspondence between the values of.

  The color channel table 5 stores a combination of the CMYK 1/2/3/4 color and the CMY output intensity corresponding to the ground color of the printing paper in the configuration shown in FIG. To do. FIG. 5 shows an example of the output intensity of the above-mentioned CMYK1 / 2/3/4 color and white background (shown as W (white) in the figure). The output intensity of Y is changed from the minimum value 0 to the maximum value 140. The output intensities of M and C are shown from the minimum value 0 to the maximum value 160.

  The image recording unit 6 sensitizes the magenta coloring layer (M layer) of the photosensitive material with red (R) light, and sensitizes the cyan coloring layer (C layer) of the photosensitive material with green (G) light. The yellow color developing layer (Y layer) of the photosensitive material is exposed to light, and development processing is performed to reveal and output basic colors Y, M, and C, thereby forming a color image. The photosensitivity by the red (R) light, the green (G) light, and the blue (B) light is performed by simultaneously irradiating light of these colors for each pixel in a dot-sequential manner.

  The control unit 1 has a function of controlling each unit and also has a function as a control unit of the present invention, and is divided into halftone dots for each of C, M, Y, K, and special color inks from image data. Based on the image data, it is determined whether the color to be output by each pixel in the image storage unit 4 is the above-mentioned CMYK1 / 2/3/4 color or the ground color of the printing paper, and the color channel A combination of CMY output intensities is obtained with reference to the table 5, and the Y, obtained from the color channel table 5 is output so that the image recording unit 6 changes the output intensities of the basic colors Y, M, and C. The output intensity data of M and C is converted into exposure output intensity data of B, R, and G, and control is performed so as to change the intensity of light of each color of the image recording unit 6. In order to realize such functions, a CPU (not shown), a program for performing overall control, a program for changing the output intensity of Y, M, and C, and various data necessary for executing each program are stored. A system memory (not shown) that constitutes a work area for storing and executing each program is configured.

  Then, the color proof creation device changes the output intensity of the basic colors Y, M, and C, so that the color created by overprinting the halftone dot images of the C, M, Y, and K inks on the printing press. Reproduce and create a color proof. Specifically, the control unit 1 refers to the color channel table 5 and controls the image recording unit 6 to change the output intensity of a plurality of basic colors based on the image data, and the image recording unit 6 controls the control. Then, image formation is performed.

(Color channel table update)
FIG. 6 is a flowchart showing the color channel table update procedure of the present invention. The color channel table update procedure will be described with reference to FIG. Hereinafter, each step will be omitted if it is step S11 in FIG. The other steps are the same.

  First, when the operator changes a color that reproduces a single ink color of the printing press, the operator operates the operation unit of the input unit 7 (S11), and the control unit 1 displays the input unit 7 in response to the operation. The resetting screen 70 is displayed on the means (S12).

  Here, the resetting screen 70 will be described with reference to FIG. As shown in FIG. 7, the resetting screen 70 includes a color selection display field 71, an output intensity display area 72, and a simultaneous adjustment soft key 77.

  The color selection display column 71 displays each single color of ink in a drop-down menu so that it can be selected, and is used to select a single color for which the output intensity of the color channel table 5 is desired to be updated.

  The output intensity display area 72 displays the output intensity of a single color selected in the color selection display field 71. The output intensity display area 72 includes an output intensity display field 73, a reset output intensity display field 74, an adjustment value. A display field 75 and an adjustment value input soft key group 76 are displayed. In the output intensity display field 73, the output intensity already set in the color channel table 5 is displayed. The adjustment value input soft key group 76 can input an adjustment value of the output intensity of the basic color by operating the “▲” key and the “▼” key. The adjustment value display field 75 displays the adjustment value in conjunction with the operation of the adjustment value input soft key group 76. Further, the output intensity updated by the adjustment value is displayed in the reset output intensity display column 74. FIG. 7 shows an example in which C is selected and an adjustment value for C is input.

  The simultaneous adjustment soft key 77 is pressed after inputting an adjustment value in the output intensity display area 72, so that the selected single color is updated and the multi-order color (CMYK 2/3/4 color) including the single color is simultaneously updated. This is a key for inputting an instruction to update output intensities of a plurality of basic colors based on an input adjustment value.

  Using this reset screen 70, the operator inputs a selection of a color for which output intensity is desired to be updated and a desired adjustment value, and presses the simultaneous adjustment soft key 77 to give an instruction for updating. In response to the monochrome adjustment value and the update instruction, the control unit 1 controls the color channel calculation means 2 to update based on the adjustment value (S13).

  First, the color channel calculation means 2 updates the output intensity of the single color selected and input with the adjustment value using the input adjustment value (S14). The output intensity updated here is displayed in the reset output intensity display field 74 of the reset screen 70. For example, a case where C is selected and the adjustment value is input will be described in detail. .

  If the combination of output intensities of C is (Y, M, C) and the input adjustment values are (Dy, Dm, Dc), the combination of output intensities after update (Y ′, M ′, C ′) Becomes (Y + Dy, M + Dm, C + Dc) by adjusting each output intensity with an adjustment value. Specifically, as shown in FIG. 7, the adjustment values (Dy, Dm, Dc) for C are (−5, +5, 0), and combinations of output intensities stored in the color channel table 5 If (Y, M, C) is (8, 22, 95), the combination (Y ′, M ′, C ′) of the C output intensity after the update is adjusted by adjusting each output intensity. (3, 27, 95) is stored in the color channel table 5 and updated.

  Next, the color channel calculation means 2 extracts a multi-color including a single color that has been selected and input an adjustment value, and outputs the multi-color output intensity of the extracted multi-color based on the ink composition and the order of overprinting. An adjustment coefficient a is obtained for the color, and the input adjustment value is updated using a value adjusted by the adjustment coefficient a (S15). That is, the adjustment values (Dy, Dm, Dc) are adjusted to (Dy × a, Dm × a, Dc × a) by the adjustment coefficient a, and the output intensity combinations (Y ′, M ′, C ′) after the update are adjusted. ) Adjusts each output intensity using the adjustment value and the adjustment coefficient a, and updates it as (Y + Dy × a, M + Dm × a, C + Dc × a).

  Regarding the update of the output intensity of the multi-order color, a case where C is selected and the adjustment value is input will be described as an example. First, a multi-order color including a single color C to which the selected adjustment value is input is extracted. The multi-order colors including C are seven colors of G (CY), B (CM), KC, CMY, KG (KCY), KB (KCM), and KCMY. The adjustment coefficients a for the seven colors are obtained as follows. Here, as described in the explanation of FIG. 2, it is assumed that the printing overlap order is printed in the order of K → C → M → Y. Further, in the following description, the transparency T of K, C, M, and Y is described as Tk, Tc, Tm, Ty, and the trapping rate TR is described as TRk, TRc, TRm, and TRy, respectively.

[Adjustment coefficient a]
Since the adjustment coefficient a: C of G (CY) is printed on the printing paper, the amount to be applied is the same as that of a single color, and the C density is reduced by the transparency of Y because the printing order is C → Y. Therefore, since the adjustment value needs to be reduced by the transparency of Y, the adjustment coefficient a is
a = Ty, referring to the coefficient table 8, a = 0.7
It becomes.
Since the adjustment coefficient a: C of B (CM) is printed on the printing paper, the amount to be applied is the same as that of a single color, and the C density is reduced by the transparency of M because the printing order is C → M. Therefore, since the adjustment value needs to be reduced by the transparency of M, the adjustment coefficient a is
a = Tm, with reference to the coefficient table 8, a = 0.6
It becomes.
The CMY adjustment coefficient a: C is printed on the printing paper, so the amount to be applied is the same as that of a single color, and because C → M → Y is the printing overlap order, C is reduced by the transparency of M and further reduced by the transparency of Y. The Therefore, since the adjustment value needs to be reduced by the transparency of M and Y, the adjustment coefficient a is
a = Tm × Ty, referring to the coefficient table 8, a = 0.6 × 0.7 = 0.42
It becomes.
KC adjustment coefficient a: Since the printing order is K → C, the amount of C placed on K follows the trapping rate of C. Therefore, since it is necessary to adjust the adjustment value with the trapping rate of C, the adjustment coefficient a is
a = TRc, referring to the coefficient table 8, a = 0.7
It becomes.
KG (KCY) adjustment coefficient a: Since the printing overlap order of K → C → Y, the amount of C on K is further reduced by the transparency of Y according to the trapping rate of C. Therefore, since the adjustment value needs to be adjusted by the trapping rate of C and further reduced by the transparency of Y, the adjustment coefficient a is
a = TRc × Ty, referring to the coefficient table 8, a = 0.7 × 0.7 = 0.49
It becomes.
KB (KCM) adjustment coefficient a: Since K → C → M in order of printing overlap, the amount of C on K is further reduced by the transparency of M according to the trapping rate of C. Since it is necessary to adjust by the trapping rate of C and further reduce the amount by transparency of M, the adjustment coefficient a is
a = TRc × Tm, referring to the coefficient table 8, a = 0.7 × 0.6 = 0.42
It becomes.
KCMY adjustment coefficient a: Since the printing order is K → C → M → Y, the amount of C on K is further reduced by the transparency of M and Y according to the trapping rate of C. Therefore, since it is necessary to adjust the adjustment value with the trapping rate of C and further reduce the amount with the transparency of M and Y, the adjustment coefficient a is
a = TRc × Tm × Ty,
Referring to the coefficient table 8, a = 0.7 × 0.7 × 0.6 = 0.29
It becomes.

Then, the updated output intensity combination (Y ′, M ′, C ′) is adjusted by using the adjustment value and the adjustment coefficient a (Y + Dy × a, M + Dm × a, C + Dc × a). By
G (CY): (66, 28, 88),
B (CM): (26, 73, 92),
CMY: (60, 74, 90)
KC: (65, 79, 94)
KG (KCY): (78, 78, 100)
KB (KCM): (72, 90, 96)
KCMY: (79, 88, 100)
Then, it is stored in the color channel table 5 and updated. The updated color channel table 5 is shown in FIG. Then, the color proof creation device creates a color proof while changing the output intensity of the basic colors Y, M, and C based on the updated color channel table. Therefore, in the created color proof, a desired single color and its single color are created. Can be reproduced.

  Here, in the present embodiment, the trapping rate TR is set for each ink, and is set to a numerical value indicating a state in which the set ink is placed on another ink. The amount to ride follows the trapping rate TRc set for C. In the above calculation, the trapping rate TRc set for C is used. However, the trapping rate TR is set for each ink in the same manner, and other inks are added to the set ink. In the case of using a numerical value indicating the state of riding on top, the trapping rate TRk set for K is used. This is because the amount of C rides on the trapping rate TRk set for the ink K below C.

  In the above description, the case of updating for one color C is shown as an example. However, in addition to C, for example, when updating M, the adjustment coefficient a ′ is obtained in the same manner, and the adjustment value for M is adjusted. What is necessary is just to add a value further. In particular, the color channel table can be updated in the same manner when not only the above-described four-color ink but also a special color ink is used.

  According to the color channel table update procedure described above, when an adjustment value is input for a single ink color and the output intensity of the basic color is updated, the output value of the basic color of the multi-order color including that single color is both input. Therefore, the color channel table can be easily updated based on the adjustment value of the output intensity of the single color. In addition, since the adjustment coefficient a is obtained for each multi-order color based on the ink composition and the printing overlap order, and the adjustment value is adjusted by the adjustment coefficient a to obtain the output intensity, the output intensity of the multi-order color can be accurately updated. Further, the adjustment coefficient a can be easily obtained from the transparency and the trapping rate set for each ink.

  The color channel table is updated using an information processing device such as a PC (Personal Computer), and the color proof creation device acquires the color channel table via a medium such as a floppy (registered trademark) disk. It is also possible to use it for image formation.

  Also, in an image output system composed of an information processing apparatus such as a PC and a color proof creating apparatus, a function as a generating means for generating the above-described color channel table and a function as an input means for inputting color channel table update And an information processing apparatus such as a PC having a function as an updating means for updating the color channel table. The color proof creating apparatus acquires the generated or updated color channel table via the interface and uses it for forming a color image. It is also possible to do so.

It is a functional block diagram which shows the structure of the color proof production apparatus which concerns on this invention. It is a figure which shows the correspondence of each color and ink which are printed. It is explanatory drawing which shows an example of a structure of the coefficient table of this Embodiment. It is explanatory drawing which shows an example of a structure of the color table of this Embodiment. It is explanatory drawing which shows an example of a structure of the color channel table of this Embodiment. It is a flowchart which shows the procedure of the color channel table update of this invention. It is a figure which shows an example of the display screen for inputting color channel table update. It is explanatory drawing which shows an example of a structure of the updated color channel table.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control part 2 Color channel calculation means 3 Color table 4 Reference table 5 Color channel table 6 Image recording part 7 Input means 8 Coefficient table

Claims (9)

A color adjustment method for reproducing a color obtained by changing the output intensity of a plurality of basic colors and printing a plurality of color materials including colors and pigments on the recording medium. ,
In response to the input of a desired adjustment value for at least one of the single colors obtained by printing each of the plurality of color materials, the plurality of colors constituting the single color to which the adjustment value is input Adjusting the output intensity of the basic color with the input adjustment value, and outputting the output intensity of the plurality of basic colors constituting a color composed of the single color to which the adjustment value is input and at least one other color material Is adjusted based on the inputted adjustment value.   The adjustment of the output intensity of the plurality of basic colors constituting the color constituted by the single color to which the adjustment value is input and at least one other color material is the order of printing of the color materials constituting the color, The color adjustment method according to claim 1, wherein an adjustment coefficient is obtained based on a numerical value indicating transparency of a color material constituting the color or a numerical value indicating a state on which the color material rides, and the adjustment value and the adjustment coefficient are used. .   The adjustment coefficient is a numerical value indicating a state in which the single color material to which the adjustment value is input is overlaid on another color material when the single color material to which the adjustment value is input is overlaid on another color material, and In the case where printing is performed on another color material on the single color material to which the adjustment value is input, a numerical value indicating a state where the single color material to which the adjustment value is input and the adjustment value are input. The product of the transparency of the color material to be overprinted on the single color material that has been printed, and when the single color material to which the adjustment value is input is printed directly on the recording medium, the adjustment value is input The color adjustment method according to claim 2, wherein the color material is transparent on a single color material.   When there are a plurality of color materials that are overprinted on a single color material to which the adjustment value is input, each transparency of the plurality of color materials that are overprinted on the single color material to which the adjustment value is input The color adjustment method according to claim 3, wherein A combination of a color of a halftone dot line portion obtained by printing each halftone image of a plurality of color materials including a color of a recording medium and a pigment on the recording medium and a combination of output intensities of a plurality of basic colors A color image forming method for forming a color image while reproducing the color of the halftone line portion by changing the output intensity of the plurality of basic colors based on a color channel table indicating a correspondence relationship,
In response to the input of a desired adjustment value for at least one of the single colors obtained by printing each of the plurality of color materials, the single color to which the adjustment value of the color channel table is input is input. The output intensity of the plurality of basic colors to be configured is updated using the adjustment value, and is configured by a single color material to which the adjustment value is input and at least one other color material from the color channel table. Extracting a color of a halftone image line portion, and updating the output intensity of the plurality of basic colors constituting the color of the extracted halftone image line portion of the color channel table based on the adjustment value;
And a step of controlling the output intensity of the plurality of basic colors to be changed based on the updated color channel table when the color image is formed.   The update of the output intensity of the plurality of basic colors constituting the color of the extracted halftone line portion is configured by the printing order of the color materials constituting the color of the extracted halftone line portion and the color. An adjustment coefficient is obtained based on a numerical value indicating the transparency of the color material to be performed or a numerical value indicating the state on which the color material rides, and an output intensity is obtained by calculation using the adjustment value and the adjustment coefficient. The color image forming method according to claim 5, wherein the color image forming method is updated.   The adjustment coefficient is a numerical value indicating a state in which the single color material to which the adjustment value is input is overlaid on another color material when the single color material to which the adjustment value is input is overlaid on another color material, and In the case where printing is performed on another color material on the single color material to which the adjustment value is input, a numerical value indicating a state where the single color material to which the adjustment value is input and the adjustment value are input. The product of the transparency of the color material to be overprinted on the single color material that has been printed, and when the single color material to which the adjustment value is input is printed directly on the recording medium, the adjustment value is input The color image forming method according to claim 6, wherein the transparency of a color material printed on a single color material is used.   When there are a plurality of color materials that are overprinted on a single color material to which the adjustment value is input, each transparency of the plurality of color materials that are overprinted on the single color material to which the adjustment value is input The color image forming method according to claim 7, wherein A combination of a color of a halftone dot line portion obtained by printing each halftone image of a plurality of color materials including a color of a recording medium and a pigment on the recording medium and a combination of output intensities of a plurality of basic colors A color image forming apparatus that forms a color image while reproducing the color of the halftone line portion by changing the output intensity of the plurality of basic colors based on a color channel table indicating a correspondence relationship,
In response to the input of a desired adjustment value for at least one of the single colors obtained by printing each of the plurality of color materials, the single color to which the adjustment value of the color channel table is input is input. The output intensity of the plurality of basic colors to be configured is updated using the adjustment value, and is configured by a single color material to which the adjustment value is input and at least one other color material from the color channel table. Updating means for extracting a color of a halftone dot line portion and updating output intensities of the plurality of basic colors constituting the color of the extracted halftone dot line portion of the color channel table based on the adjustment value;
A color image forming apparatus comprising: a control unit configured to control the output intensity of the plurality of basic colors based on the updated color channel table when forming the color image. .

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