JP2004291236A - Image information processing method, image information processing apparatus, image formation method, image output system, and computer program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently obtain proof images of a high image quality corresponding to a printing order of ink. <P>SOLUTION: The image information processing apparatus is configured to obtain and output color characteristics for each color of a printing target set from a target printed matter 2; calculate color characteristics of superposed printing colors formed by superposing and printing colors of the printing target, by order corresponding to the printing order on the basis of the acquired color characteristics; convert each of the color characteristics to a density of a basic color with reference to a density characteristic table of color characteristics to basic color densities of a proof image output device prepared beforehand; store the density of the basic color to each converted color as a table; output data of the stored table to the proof image output device 1 and print the data; and obtain a highly precise proof image from a small number of measurements of colors of the printed matter. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an image information processing method, an image information processing apparatus, an image output system, an image forming method, and a computer program for generating a proof in which a user operates a computer to check the finish of a printed matter in advance.
Also, in a method of forming a proof image, the technique relates to generation of a digital color proof in which a silver halide light-sensitive material or a silver halide color light-sensitive material (hereinafter, simply referred to as a light-sensitive material) can be preferably used. The present invention relates to generation of a digital color proof capable of efficiently obtaining a high-quality proof image corresponding to various printing conditions.
[0002]
[Prior art]
In the field of printing, silver halide photographic materials are widely used today because of their high sensitivity, excellent color reproducibility, and suitability for continuous processing. Due to these characteristics, silver halide light-sensitive materials have been widely used not only in the field of photography but also in the field of printing, in the field of so-called proofing for checking the state of the finished printed matter in the middle of printing. ing.
[0003]
In the field of proofing, an image edited on a computer is output to a printing film, and the developed film is appropriately exposed and separated and exposed to light to produce yellow (Y), magenta (M), and cyan (C). By forming an image and forming an image of the final printed matter on color photographic paper, it has been performed to determine the suitability of the layout and color of the final printed matter.
[0004]
Recently, a method of directly outputting an image edited on a computer to a printing plate has gradually become widespread. In such a case, it is desired to obtain a color image directly from the data on the computer without using a film. Had been rare.
[0005]
For this purpose, various methods such as a sublimation type / melt heat transfer method, an electrophotographic method, and an ink jet method have been tried, but a method that can obtain a high-quality image is expensive and has low productivity. However, there is a disadvantage that the image quality is inferior in the system which is low in cost and excellent in productivity. A system using a silver halide photosensitive material enables high-quality image formation, such as formation of an accurate halftone image, due to excellent sharpness and the like, while continuous processing is possible as described above. In addition, since images can be simultaneously written in a plurality of color image forming units, high productivity can be realized.
[0006]
In recent years, in the field of printing, so-called digitization has progressed, and there has been an increasing demand for obtaining images directly from data in a computer. For the reasons described above, silver halide photosensitive materials have begun to be advantageously used in this field.
[0007]
In such a method, it is possible to divide a halftone dot into smaller units (here, this is expressed as a pixel) and reproduce the halftone dot as an aggregate by exposing this pixel with an appropriate exposure amount. It is possible. As a simple example, if one halftone dot is composed of 100 pixels, halftone dots are formed by exposing 50 pixels so that halftone% can be developed. You can do it. A parameter called dot gain is used to express printing characteristics. The dot gain can be changed by changing the number of pixels that can be developed. If this pixel is present, for example, at a place where the printing yellow (Y) ink and the magenta (M) ink overlap, it is possible to reproduce this pixel by coloring it red. At this time, it is not always necessary to combine the conditions for obtaining Y and M on the proof, and it is possible to set separately (for example, a color equivalent to Y + M directly). As a result, a great advantage such as a visual adjustment of a deviation due to a difference in color material can be obtained.
[0008]
Further, in printed matter, printing using a special color ink may be performed in order to aim at a color or a special printing effect that cannot be expressed by the process ink.
[0009]
In a system that forms an area gradation image based on digital data using a silver halide photosensitive material, the density of yellow (Y), magenta (M), and cyan (C) can be changed by arbitrarily changing the exposure amount of each layer. , It is possible to reproduce an arbitrary color tone in a fixed color gamut determined by the color development ratio of the three color components. In other words, in addition to the 15 colors excluding white that can be expressed by a combination of the process inks yellow (Y), magenta (M), cyan (C), and black (K), almost infinite color tone expression is possible. It is possible to reproduce a color tone that is close to the special color.
[0010]
In order to reproduce an arbitrary color tone such as a color tone and a special color expressed by a combination of process inks using a silver halide photosensitive material, a density at which yellow (Y), magenta (M), and cyan (C) are developed. It is necessary to combine the components by appropriately adjusting the amount of exposure light.
[0011]
Although a system using a silver halide photosensitive material can realize such a very useful proof system, as described above, as the number of color plates of a target print increases, How to define the conditions was a very big issue.
[0012]
Further, in a system using a silver halide photosensitive material, the same color material as that used for printing cannot be used. Therefore, in order to obtain a visually similar image, for example, a color shifted as a measurement value in the CIELAB color space is used. There were issues such as the need to adjust.
[0013]
The claims of Patent Document 1 disclose a color image proofing apparatus that adjusts the amount of transmitted light by controlling ON / OFF voltage values applied to an AOM (acousto-optic modulator), thereby adjusting the color density of a color photosensitive material. It is disclosed that this makes it possible to change the color density and the density of a blank portion, to form an image similar to printing, and to perform proofreading of special color printing. However, no specific means such as how to determine image output conditions when performing special color printing for quality improvement is described or suggested. Although it is necessary to obtain a proof that can accurately determine the fuzzy characteristic of a spot color, there is no device that can achieve this.
[0014]
An apparatus using a silver halide photosensitive material has been proposed as a proof image forming apparatus, and it is disclosed that the density of halftone dots can be varied (Digital Consensus Pro Pamphlet, Konica Graphic Imaging Corp. (2002)).
[0015]
The claim of Patent Literature 2 discloses an image forming method in which the density and the dot gain using a directly modulated LED as a light source are independently adjusted, and a proof image having a small difference from a printed image can be easily obtained. Is disclosed. However, there is no description or suggestion about how to adjust each color to satisfy the visual image reproducibility, and above all, the present invention relates to such a device. It relates to technology for more effective use.
[0016]
The claim of Patent Document 3 discloses, as a proof image forming method for a printed material using a special color plate, a process color conversion process, a special color reference process, a special color conversion process, and a combining process of combining process color conversion image data and the special color conversion image data. Discloses an image forming method including an output process. The simplest model of how to adjust the color of the printed matter and the color of the proof is to make the density or the values of L *, a *, and b * the same for both. In addition, in a color proof using a silver halide photosensitive material, there is a problem that it is necessary to adjust a color tone due to a difference in color material from printing. Actually printing and performing all the fake settings is costly and wastes time. There is a high demand for a system capable of predicting fuzz from a measurement of the color of a small number of printed materials. Patent Document 3 does not describe such a problem and does not suggest a method for easily determining a color.
[0017]
The claim of Patent Document 4 discloses a color proofing method for performing a simulated calculation of the overprinting of each color based on the printing order and transmittance of each color in the printing press. A color proofing method having good color reproducibility is provided by taking into account the transparency of the special color ink. However, the publication column 0008 of Patent Literature 4 states that “Transmissivity is an area ratio (%) that is not concealed by an ink having a concealing property (an impermeable color ink), that is, the lower color is viewed from the surface of the printed matter. It is described as "a degree (%) that affects the color". "The simulation operation process is a method of multiplying the pixel value and the transmittance for an opaque color that is not affected by the lower color in the overprinting ( Effective pixel value) is subtracted from the transmittance before the operation of printing the opaque color to generate a new transmittance, and the new transmittance is used as the effective pixel value of the next lower color in the printing order Color proofing method used in the calculation process ". That is, the order of printing is considered in distinguishing whether the opaque color ink (which does not transmit light at all) is above or below. Similarly to the present invention, the color to be reproduced is determined by calculation, but the disclosed contents relate to a limited method, and the present invention makes the density of halftone dots variable, The feature is that the light transmittance of the overprinted upper color ink itself can be treated as a continuous numerical value, and the change in density that makes it difficult to color the upper color with the lower color ink can be treated as a continuous numerical value. No publication suggesting such treatment is found in the above-mentioned publication.
[0018]
[Patent Document 1]
JP-A-5-66557 [Claim]
[Patent Document 2]
JP 2001-305701 A [Claims]
[Patent Document 3]
JP-A-10-248017 [Claims]
[Patent Document 4]
JP-A-11-296664 [Claims]
[0019]
[Problems to be solved by the invention]
The problem to be solved by the present invention is to provide a proof for checking the finish of a printed matter in advance, in particular, by changing the density of halftone dots, it is possible to express the difference in the finish due to the difference in printing paper, and to print a printed matter using a special color. An image information processing method, an image information processing apparatus, and an image output system capable of forming a digital color proof capable of expressing a finish and further enabling a user to operate a computer to generate a proof with high accuracy and high reproducibility , An image forming method, and a computer program. Another object of the present invention is to realize a digital color proof capable of efficiently obtaining a high-quality proof image corresponding to various printing conditions from a small amount of measurement data.
[0020]
[Means for Solving the Problems]
To solve the above problem, the configuration is as follows.
[0021]
The invention according to claim 1 is an image information processing method for processing image data of a printed matter in order to reproduce and output a color in which a plurality of colors are overprinted by a proof image output device, the method including the plurality of colors. An acquisition step of obtaining and outputting color characteristics for specifying a predetermined color; and, based on the color characteristics acquired in the acquisition step, a color characteristic of an overprinted color formed by overprinting the plurality of colors. A calculating step of calculating in the order of the overprinting, and a color property table of the proof image output device and a density characteristic table of a basic color density, which are prepared in advance, and the color property and the calculation output in the acquiring step are referred to. Converting the color characteristics calculated in the step to obtain a density of each of the basic colors; a storage step of storing the density of the basic colors obtained in the conversion step; and Remembered A step of printing the data of the serial table and output to the proof image output apparatus, characterized by comprising a.
[0022]
According to a second aspect of the present invention, in the image information processing method according to the first aspect, in the calculating step, for each of the colors that are overprinted to form the overprinted color, the color is formed by overprinting the color. The color characteristics of the overprinted colors are calculated by sequentially calculating the color characteristics of the colors to be printed.
[0023]
The invention according to claim 3 is the image information processing method according to claim 2, including a step of storing the color characteristics of the colors sequentially calculated in the calculation step, wherein the calculation step includes the step of storing the color characteristic. And calculating a color characteristic of a color formed by printing another color on the color based on the color characteristic of the color.
[0024]
According to a fourth aspect of the present invention, in the image information processing method according to the second or third aspect, the calculating step includes the step of determining a color characteristic of the color to be overprinted and a color below the color, The color characteristic of a color formed by printing the plurality of colors on the basis of the trapping ratio of the lower color and the transparency of the color is calculated.
[0025]
According to the fifth aspect of the present invention, a proof image output device capable of reproducing a color obtained by printing a plurality of colors and outputting a printed material, and specifying a predetermined color including the plurality of colors can be specified. The predetermined color acquired by the acquisition device is connected to an acquisition device for acquiring color characteristics, and refers to a density characteristic table of a color characteristic versus a basic color density of the proof image output device prepared in advance. An image information processing apparatus for converting the color characteristics into density data of a basic color, outputting the converted density data of the basic color to the proof image output apparatus, and printing the printed matter. A GUI unit capable of performing display for inputting the order of the overprinting of the plurality of colors, and an input based on the GUI unit based on the color characteristics acquired by the acquiring device. Calculating means for calculating the color characteristics of the overprinted color formed by overprinting the plurality of colors in the order of overprinting; and A conversion unit that converts the color characteristics of the predetermined color output by the above and the color characteristics of the overprinted color calculated by the calculation unit to obtain density data of each of the basic colors; Storage means for storing the density data of the basic color acquired by the conversion means for transmission to the proof image output device.
[0026]
According to a sixth aspect of the present invention, there is provided an image forming method in which a proof image output device reproduces a color in which a plurality of colors are overprinted to form an area gradation image by using halftone dots as an aggregate of a plurality of pixels. A preparation step of obtaining a basic color density vs. light amount characteristic for performing exposure by the proof image output device, and an obtaining step of obtaining and outputting a color characteristic for specifying a predetermined color including the plurality of colors, A calculating step of calculating the color characteristics of the overprinted color formed by overprinting the plurality of colors in the order of the overprinting based on the color characteristics acquired in the acquiring step, and outputting the proof image prepared in advance. With reference to a density characteristic table of the color characteristic of the device versus the basic color density, the color characteristic output in the acquisition step and the color characteristic calculated in the calculation step are converted, and the density of each of the basic colors is converted. Get A conversion step, an output step of outputting pixel information for identifying a pixel, and based on the pixel information output in the output step, referring to the basic color density versus light amount characteristic obtained in the preparation step, Calculating the amount of light in pixel units from the density of the basic color obtained in the conversion step, wherein printing is performed by controlling the exposure amount by the proof image output device in pixel units.
[0027]
According to a seventh aspect of the present invention, in the image forming method according to the sixth aspect, in the calculating step, for each of the colors to be overprinted to form the overprinted color, the color is formed by overprinting the color. The color characteristics of the overprinted colors are calculated by sequentially calculating the color characteristics of the colors.
[0028]
The invention according to claim 8 is the image forming method according to claim 7, including a step of storing the color characteristics of the colors sequentially calculated in the calculation step, wherein the calculation step includes the step of storing the color characteristic. Based on the color characteristics of the color, a color characteristic of a color formed by printing another color on the color is calculated.
[0029]
According to a ninth aspect of the present invention, in the image forming method according to the seventh or eighth aspect, the calculating step includes the step of calculating the color characteristics of the color to be overprinted and the color under the color, the color and the color. The color characteristic of a color formed by printing the plurality of colors is calculated based on a trapping rate of a lower color and transparency of the color.
[0030]
The invention according to claim 10 is an image output system configured to include a proof image output device for printing a plurality of colors, and outputting an area grayscale image as an aggregate of a plurality of halftone dots, A storage unit for storing a basic color density vs. light amount characteristic for performing exposure by the proof image output device; an obtaining unit for obtaining and outputting a color characteristic for specifying a predetermined color including the plurality of colors; Calculating means for calculating the color characteristics of the overprinted color formed by overprinting the plurality of colors based on the color characteristics acquired by the acquiring means in the order of the overprinting; and the proof image output prepared in advance The color characteristics output from the acquisition unit and the color characteristics calculated by the calculation unit are converted with reference to a density characteristic table of the color characteristics of the device versus the basic color density, and A conversion unit for obtaining a color density; a pixel generation unit for outputting pixel information for identifying a pixel; and the basic color density stored by the storage unit based on the pixel information output by the pixel generation unit. Means for calculating the amount of light in pixel units from the density of the basic color obtained by the conversion means, with reference to the light amount characteristics, based on the amount of light obtained by the calculation, in units of pixels. The proof image output device controls the amount of exposure and prints out.
[0031]
According to a twelfth aspect of the present invention, there is provided a proof image output device capable of reproducing a color obtained by printing a plurality of colors based on data corresponding to a density of a basic color and outputting a printed material, and including the plurality of colors. An acquisition device for acquiring a color characteristic capable of specifying a predetermined color, and a computer program for performing desired printing by controlling a computer to perform exposure by the proof image output device in advance. Acquiring the basic color density vs. light amount characteristic, performing a display for setting the order of the overprinting of the plurality of colors when outputting the printed matter, and the color acquired by the acquiring device. Calculating a color characteristic of an overprinted color formed by overprinting the plurality of colors in the set order of overprinting based on the characteristic; With reference to a density characteristic table of the basic color density, the color characteristic of the predetermined color acquired by the acquisition device and the color characteristic of the calculated overprint color are converted, and Acquiring the density data of the basic color; and storing the converted density data of the basic color for transmission to the proof image output device.
[0032]
BEST MODE FOR CARRYING OUT THE INVENTION
First, in order to deepen the understanding, terms according to the present invention and techniques related to the terms will be described.
[0033]
[Explanation of terms and involved technologies]
(1) Color notation
The notation of the color of the printing ink used in the description in this specification conforms to FIG.
[0034]
(2) Formation of halftone image (color, special color)
Although briefly described in the related art, it will be additionally described. FIG. 1 is a schematic diagram of a halftone dot in a digital color proof. As shown in FIG. 1, an image is divided into pixels (represented by a circle in the figure), and a halftone dot is represented as an aggregate of the pixels. At this time, the overlapping portions of the halftone dots share the pixels. For example, in FIG. 1, Y (yellow), M (magenta), and C (cyan) halftone dots are used as the basic colors. Therefore, the pixels shared (overlapping) by the halftone dots of Y and M are Pixels shared by red and Y halftone dots and C halftone dots are represented by green (G), and pixels shared by Y, M and C halftone dots are represented by black (GY: also referred to as gray).
[0035]
Further, depending on the printed matter, a special color other than YMC or YMCK, a so-called “special color” may be used. This special color ink plate is called a “special color plate”. As the special color ink, various inks such as gold, silver or other metallic color inks are used in addition to green and orange inks. Further, the density of the special color ink may not be uniform, and a mixture of glitter and gold powder may be used. The special color plate is often used when reproducing an image component such as a logo which is designated as a special color in advance, or when it is desired to enhance color reproducibility of a color image by printing with a special color ink. Although not shown in FIG. 1, when there is a dot of the special color plate, this can be expressed by adjusting the color of the corresponding pixel to a color approximate to the special color. Can be expressed by adjusting the colors shared by the plates to colors that take into account the order of overprinting, the colors of the individual plates, and the characteristics of each ink (transparency, ease of ink application, etc.).
[0036]
(3) Target print and measurement (acquisition of color data)
In order to determine image forming (printing) conditions, it is necessary to examine how each color is reproduced in an actual printed matter. For this reason, it is necessary to acquire basic data for printed matter using an ink used in actual printing and a proof image output device. In the present invention, this is called a target print. By doing so, it is possible to accurately determine the conditions necessary for color reproduction. Therefore, the target printed material preferably includes at least printed materials using the Y, M, C, and K process inks, and further preferably includes an overprint color in which K and Y overlap. In printing including a special color, it is preferable to include a printed material with the special color ink in addition to a printed material with the process ink, and it is preferable to include a printed material in which the special color ink and the process ink are overprinted. In terms of color reproduction accuracy, it is preferable that the number of printed materials is large, but the load of measurement is also increased.
[0037]
Further, even if the present invention states that the target printed matter is measured, even if the object can be achieved by reading data from an appropriate medium, such as when using the same ink as the previously measured ink. Describes the measurement as including this. In addition, it is also possible to substitute representative ink data in relation to the required accuracy, and it is described that measurement is performed in such cases.
[0038]
Measurement of density, L * a * b * and color
The term “density” as used herein mainly means optical density, but can be replaced with another quantity having substantially the same meaning. For example, L *, a *, b *, and the like in the CIELAB color space can be given as representative values that can be converted. In addition, coordinate values in the CIELAB color space and the XYZ color space can be preferably used. The CIELAB color space refers to CIE 1976 (L * a * b * color space), and how to obtain the coordinates is described in JIS Z 8729-1994. Here, L * a * b * is referred to as “characteristic” of the color in the present invention.
[0039]
[Schematic description of overall configuration]
FIG. 2 shows an example of the overall configuration of an image output system necessary for carrying out the invention. FIG. 3 is a diagram showing a detailed functional configuration of the image information processing apparatus 100 which is a main configuration of the present invention in FIG. 2. include. FIG. 4 is a diagram for explaining a schematic operation flow of the configuration of FIG. First, a schematic overall configuration will be described with reference to FIG.
[0040]
In FIG. 2, a proof image output apparatus 1 temporarily stores data and sets a buffer for adjusting recording timing and a printing medium (for example, a photosensitive material) for each pixel by reflecting conditions such as ink and printing paper. There is provided an exposure means for obtaining a desired proof by performing exposure, a drum for transporting a photosensitive material, and a control means for controlling these means under necessary conditions. Further, the exposure unit includes various light sources (laser or light emitting diode (LED)), a unit for adjusting the amount of light from the light source, and scanning the light from the light source in the main scanning direction or the sub-scanning direction to a predetermined position on the photosensitive material. Scanning means for printing. The control means includes a CPU (computer) and an image output control program for controlling each unit, a memory for storing the image output control program, exposure data, and the like. The CPU executes the image output program to control the control unit. Functioning as
[0041]
Since the exposure means (details will be described later in the column of [Exposure Means]) determines the amount of light of each light source from the input density data and performs exposure, the image information processing apparatus 100 in FIG. Data corresponding to the characteristic (hereinafter referred to as a characteristic file of the exposure means to be referred to when generating the data corresponding to the exposure means). ).)). This point is important, and will be described later in the section "Generation of density characteristic file".
[0042]
The measurement device 3 is a measurement device (acquisition device) that measures to acquire the characteristics of each color of the target print 2. The characteristics of each color include density, but in this example, L *, a *, and b * in the CEILAV color space are measured and output. Here, if not distinguished, the characteristics of each color may be collectively referred to as L *, a *, and b *.
[0043]
The image information processing apparatus 100 has a GUI 200 (Graphical User Interface means: see FIG. 3), also serves as an overall control, and transmits measurement data L * a * b * for each color from the measurement apparatus 3 to the density characteristic. With reference to the data of the file, the data is converted into the basic colors, that is, the respective densities of Y, C, and M in this example, and output to the proof image output device 1.
[0044]
The hardware configuration of the image information processing apparatus 100 includes a CPU 100a and a memory 100b. In the memory 100b, a GUI program (called a graphic user interface, a program that allows easy visual input operation) for the operator to visually operate the operation unit 5 while looking at the display unit 4 In addition, a control program for exchanging information with the measurement device 3 and the proof image output device 1 inside the image information processing apparatus 100 is provided so as to be executable by the CPU 100a. Note that the image information processing apparatus 100 may be a general computer or may be housed in the same housing as the proof image output apparatus 1, and can be implemented by installing the program including the GUI and control. Have been. (Details of each unit are described in [Example 1].)
[0045]
[Explanation of Exposure Means] (In this column, those having no names are not shown.)
[0046]
Receiving halftone image data representing the respective intensities (density or light amount corresponding to the density: exposure energy) of each of Y, M, and C (or YMCK) generated by the image information processing apparatus 100, and stores the halftone image data in a temporary buffer. This is read out by a dot clock, and a light source, for example, a green laser light source, a red laser light source, or an infrared laser light source emits light corresponding to the intensity of Y, M, and C of the halftone dot image data, and emits ink. And / or exposing an image having a color corresponding to the color of the printing paper (for example, a white background).
[0047]
Further, an exposure control unit (comprising a CPU and a program) emits light from an optical system including a light source based on the count of a pulse signal encoded by a sensor detecting the position of the leading end of the photosensitive material on the drum. It is controlled so that the image recording area of the photosensitive material is located at the irradiation position of the light to be irradiated. Then, an image output (exposure) of a halftone image is performed on the photosensitive material held on the drum.
[0048]
The image recording density of the image recorded on the photosensitive material is preferably 600 dpi or more (especially 1000 dpi or more, more preferably 1200 dpi or more) in both the main scanning direction and the sub-scanning direction from the viewpoint of the reproducibility of gradation by a halftone dot image. Further, from the viewpoint of saturation of reproducibility of gradation by a halftone dot image, image recording speed, apparatus cost, and the like, it is preferable to be 10,000 dpi or less (especially 5000 dpi or less) in both the main scanning direction and the sub-scanning direction. The image recording densities in the main scanning direction and the sub-scanning direction are indicated in units of dpi indicating how many pixels to be image-recorded are arranged in a length of 1 inch in the main scanning direction or the sub-scanning direction.
[0049]
In addition, it is preferable that one halftone dot is recorded from 100 or more (especially, 200 or more) pixels because the reproduction is close to an actual printing halftone dot. In addition, it is preferable that one halftone dot is recorded from 2,000 or less pixels, because image data can be easily handled and image data can be processed at high speed.
[0050]
Further, the number of recording pixels per second of each color of the exposure light is preferably 3,000,000 pixels / second or more (especially 10,000,000 pixels / second or more). The number of recording pixels per second of each color of the exposure light is preferably 4 billion pixels or less (particularly 500 million pixels or less). Thereby, the driving circuit and the exposure output intensity are stabilized, and it is possible to achieve both high-speed image recording and high-definition image recording. In addition, the adjustment is easy, which is preferable in terms of cost.
[0051]
As the optical hardware as a means for performing the above-mentioned exposure, for example, by arranging ten LEDs of B as a light source in the main scanning direction and delaying the timing of the exposure little by little, the same location can be replaced with ten LEDs. It is adjusted so that it can be exposed by LED. Also, an exposure head was prepared in which ten LEDs were arranged in the sub-scanning direction, and exposure for ten adjacent pixels could be performed at one time. For G and R, exposure heads were prepared by combining LEDs in the same manner. The diameter of each beam was about 10 μm, the beams were arranged at this interval, and the sub-scanning pitch was about 100 μm. The exposure time per pixel was about 100 nanoseconds.
[0052]
Explaining an example using a silver halide photosensitive material, image data (density data) is finally converted into exposure data for each pixel, and transferred to exposure means for image exposure. FIG. 23A shows a flow of data transfer from image data to exposure means.
[0053]
FIG. 23A is a diagram illustrating an example of data in a process of converting image data (density data) to exposure data used for image output performed in the image information processing method, the image information processing apparatus, the image output system, and the program according to the present invention. 23B. These can be arbitrarily divided and integrated within a range that does not impair the effects of the present invention, and different amounts (for example, those expressed as density values are expressed by L *, a *, b *, etc.) May be expressed as
[0054]
Here, a method of obtaining an exposure amount for each pixel will be described based on FIGS. 23A, 23B, and 24. First, the number (counter: i) of a pixel from which data is read is set to 1 (S21 in FIG. 24), and image data indicating whether there is Y, M, C, K, and a spot color in pixel 1 is shown in FIG. Read as in a) (S22). Next, the color of the pixel is determined by combining which color is being developed (S23). This is accomplished by referencing a table. For example, in pixel 1 in FIG. 23A (a), only Y is colored, so in the column where only Y is 1 in the discrimination table of FIG. 23A (b), the pixel color is Y. It is determined (FIG. 23A (c)). In the pixel 3, since Y and M are colored, the color of the pixel is R. Similarly, the color of the pixel 4 is also K because only K is colored, and the color of the pixel 5 is K + M, which is an overprint color, since the pixel 5 is colored by K and M. By such conversion, image data for each pixel is created as shown in FIG. Next, an exposure amount to be given to each of the Y, M, and C image forming layers in order to create this color is read from a table (S24 in FIG. 24), and the exposure amount to be given to each layer for each pixel is arranged as image data. This data is transferred to the proof image output device 1 (exposure means) (S25 in FIG. 24).
[0055]
A specific flow of this operation will be described with an example in which the characteristics of a silver halide photosensitive material are represented by an analytical density (integrated by multiplying by 100). Analytical density of each layer is obtained from the color of the pixel with reference to the density table of each photosensitive layer for each color with reference to FIG. 23B (d) (color correction table: density values are coded here). In this example, in FIG. 23B (d), it can be seen that pixel 1 develops only Y at level 1 (analytical density 110). Based on this, it can be seen from the photosensitive material characteristic table of FIG. 23B (f) that the exposure amount of Y is level (n−4). Similarly, the exposure level for M and C can be determined. In this way, the exposure data for each pixel shown in FIG. 23B (g) is created.
[0056]
When the processing for each pixel is completed, the counter is incremented by 1 and the processing for the next pixel is performed. Hereinafter, this process is repeated to create exposure amount data for each pixel. The timing of data transfer to the image output means may be performed in pixel units, at the time when data processing required for one main scan is completed, or at the time when all data processing is completed. Good. The image output means converts this data into a signal for controlling the device as necessary, and performs exposure.
[0057]
The proof image output device 1 performs exposure by converting the exposure amount data for each pixel into a drive signal of an exposure unit as necessary. The process of converting the signal into a drive signal for the exposure means can be included in the control means. In the proof image output device 1, the exposure timing may be adjusted using a data buffer as needed.
[0058]
FIG. 23A shows the data structure assumed at this time. It is assumed that the image data has only data on whether or not each color is colored in the order of pixels. As described with reference to FIGS. 23A and 23B, the color of the pixel is determined by referring to the table from the pattern of the combination of Y, M, C, K, and the presence or absence of coloring of the special color. , M, and C, the exposure amount to be applied to each layer is determined with reference to the table of the exposure amount of the image forming layer. As described above, the separation between the determination of the pixel color and the determination of the exposure amount of each image forming layer from the pixel color is performed, for example, because R is not a simple addition of Y and M of a single color, but is independent. It can be set, and may be expressed by simple addition according to the required specification. By being able to set independently, an image closer to printing can be obtained, and an image in the case of printing in two colors of green and red using two image data can be obtained. It can be used for checking, and a highly useful system can be realized.
[0059]
Although the above description has described a case where the number of exposure devices is one, if the number of exposure devices is ten in the sub-scanning direction, pixels 1 to 10 represent pixels arranged in the sub-scanning direction, Data that is shifted by one pixel in the main scanning direction may be read as being represented by pixels 11 to 20.
[0060]
[Printing Conditions in Examples]
Here, the printing conditions and the like of the embodiment to be described below are shown in advance. The outline of the conditions is as follows: the target color is S1 (transparent light green ink having a large content of medium) and the target color is S2 (metal silver ink having a low transparency). However, in this example, the detailed conditions are as follows.
・ Process ink: Space color Varius G, manufactured by Dainippon Ink and Chemicals, Inc.
-Special color ink color S1: 75.1% of F gloss medium manufactured by Dainippon Ink and Chemicals, Inc., 21.8% of green for color guide, 3.1% of FG45 transparent yellow 3.1% DIC No. Fifteen
-Special color ink color S2: Nippon Ink Chemical Industry Co., Ltd. NCP Silver (silver) DIC No. 621
Transparent component: coloring component S1 75.1: 24.9 S2 0: 100
・ Printing order: K → C → M → Y → S1 → S2
・ Printing machine: Roland R704
・ Paper: Toshibishi Art 110kg / 46 size KPG Thermal CTP Plate TP-R manufactured by Mitsubishi Paper Mills, Ltd.
・ Screen: 175 line chain dot
-Target density value (DIN-NB): Y = 1.1, M = 1.5, C = 1.5, K = 1.8
・ Target dot gain: 17% (50% part)
Measurement conditions: The target printed matter was placed on a table with two 110 kg of Toshibishi art placed on top of each other, and the L * a * b * values were measured using a X-Rite 528 densitometer as the measuring device 3.
Preparation of target printed matter: A printed matter overprinted with each ink alone and in various combinations of a total of six plates including two special color plates was prepared.
[0061]
[Generation of density characteristic file]
The density characteristic file needs to be generated and prepared in advance as described above. In other words, the relationship between the combination of the amounts of cyan, magenta, and yellow coloring of the silver halide photosensitive material prepared in advance, and the relationship between the density expressed by the combination and the color characteristic L * a * b * (also called color tone). It is necessary to use a table (density characteristic file). The density characteristic file is created by using a light source having a different wavelength based on digital data, performing image exposure by arbitrarily changing the amount of light, and forming a silver halide emulsion layer capable of developing cyan, magenta, and yellow. This can be achieved by creating a combination of silver photographic materials that are arbitrarily colored, measuring the density or color tone, and correlating them with the color correction table. Further, the intermediate area can be set by complementing the data without creating a combination of all the color corrections of cyan, magenta, and yellow.
[0062]
[Silver halide photosensitive material and development processing]
As the silver halide photosensitive material, the silver halide photosensitive material No. 1 described in Example 1 of JP-A-2002-341470 is used. 101, the B, G, and R light sources are independently illuminated by changing the light emission intensity by the above-described exposure means (exposure head), and after exposure, the development described in Example 1 of JP-A-2002-341470. Processing was performed. The Y, C, and M status T densities of this sample were measured, and a light-sensitive material characteristic table showing the correspondence between light intensity and color density was obtained. FIG. 5 shows the results. The light amount value is shown as a relative value with the maximum light amount being 4000.
[0063]
[Sensitive material property table]
The photosensitive material (photosensitive material) characteristic table is a table corresponding to a characteristic curve well known in the photographic industry, and represents a relationship between a density and an exposure amount necessary for obtaining the density. To create the photosensitive material characteristic table, exposure is performed by continuously or intermittently changing the exposure amount from low exposure amount to high exposure amount, and the density of the image generated through development processing is measured, exposure amount and color development It is obtained by associating the relationship of the density.
[0064]
For example, the relationship between the energy (exposure amount) and density required for image formation can be determined by creating a color patch with all combinations of the energy changed in arbitrary increments and storing the results as a database. When the color of is determined, the energy to be applied to each layer can be determined by referring to this database. However, in this case, in order to improve the accuracy, it is necessary to perform an enormous amount of measurement and create a database, and to change the characteristics of the photosensitive material (in addition to the variation due to manufacturing variations of the photosensitive material, the performance of the processing solution, and the like). (Which fluctuates due to change) is required separately. On the other hand, the method using the photosensitive material characteristic table is preferable because the table can be rewritten to absorb the fluctuation.
[0065]
[Density characteristic file]
With reference to the above-described light-sensitive material characteristic table, 15 × 19 × 19 colors, and a total of 5415 colors can be obtained by combining the light amounts of B, G, and R for developing the respective densities of C, M, and Y shown in FIG. The patches were output, and the L *, a *, b * and status T, Y, M, C densities were measured. Next, L *, a *, and b * of the color patches, the Y density of the Y patch colored only with the B light given at the time of creating the patch, and the C density of the C patch colored only with the G light The density characteristic file was created by determining the M density of the M patch developed only with the R light and creating a table corresponding to these three amounts. Although illustration is omitted because the data of 5415 colors is enormous, the color is represented by the parameters of L *, a *, and b * in the three-dimensional coordinates of the density of Y, M, and C as shown in FIG. Be identified.
[0066]
The density characteristic file created in this way is stored in the storage unit 13 shown in FIG. 3, which is a configuration of the present invention. It is desirable to create the density characteristic file by measuring all colors, but it is also possible to measure 18 colors, 6 colors, etc., and then calculate the fuzzy state of the special color (described in a second embodiment described later). ).
[0067]
[Color Correction Table]
As described above, in a digital color proof, an image is decomposed into pixels, and a halftone dot is reproduced as an aggregate of the pixels. For this reason, when the color of a pixel is determined as image data, this color is specifically defined. That is, even if the image data is red, it is necessary to specify whether the image data is dark red, pale red, purple-red or yellow-red. A table for performing this specification is a color correction table, and its accuracy and the like are important.
[0068]
The number of colors defined in the color correction table is determined by the number of inks used in printing, the required reproduction accuracy, and the like. For example, the combination of process inks Y, M, C, K and two special colors, K, Y, Taking into account the combination of M and C, there are 16 colors including the portion without ink (white: W), and 64 colors when considering the overlap of this and two special colors.
[0069]
Next, a method of creating a color correction table will be described. One method is to prepare a printed material in which inks corresponding to the above combinations are overprinted, and measure this. Although this is ideal, it is necessary to make corrections due to differences in color materials as described above, and the number of types of special color inks is very large, and the finish varies greatly depending on the type of printing paper. For this reason, since it is practically impossible to obtain accurate data in all cases, it is preferable to obtain the data from a small number of data by some arithmetic means. Details will be described in the first embodiment.
[0070]
[Explanation of analytical concentration]
Analytical density is a concept of density that is often used in the field of photography. When Y, M, and C dyes are formed in an arbitrary amount, and when only the Y dye is formed in the same amount, the B density is analyzed analytically. The G density when only the M dye is colored in the same amount is called the analytical G density, and the R density when only the C dye is colored in the same amount is called the analytical R density. Analytical concentration is a conceptual quantity, but can also be determined by calculation. For analytical concentrations, see T.W. H. James, Ed., The Theory of The Photographic Process, Macmillan, New York, p. 524-529 (1977), which can be determined with reference to this. A useful embodiment of the present invention is a system using a silver halide photosensitive material having a reflective support. In this case, it is preferable that the analytical density is also represented as the reflection density. Here, the amount called the analytical concentration may be a numerical value converted from the original analytical concentration. As for the handling of numerical values, it is preferable to multiply the analytical concentration by 100 and convert it to an integer, because it is easier to handle.
[0071]
[Advantages of Combining Color Correction Table and Sensitive Material Property Data]
As a method of determining the conditions under which the pixels can be created, for example, the relationship between the energy required for image formation and the density, a color patch is created with all combinations of the energy changed at arbitrary intervals, and If an arbitrary color is given by using the measured result as a database, the energy to be given to each layer can be obtained by referring to this database. However, in this case, in order to improve the accuracy, it is necessary to perform an enormous amount of measurements and create a database. On the other hand, in the method of expressing by the analytical density, by determining the relationship between the energy applied to each of the Y, M, and C layers and the color density, it is possible to accurately obtain the necessary energy with a small amount of data. There is an advantage that it is easy to respond to the change of the color material of the photosensitive material or the like.
[0072]
More importantly, in the proof image output apparatus 1, the exposure means, particularly, the density and characteristics of the color development which fluctuate from the reference conditions due to fluctuations in the exposure amount due to the environment and fluctuations in the activity of the development processing over time, etc. (Color tone) may be shifted. In preparation for this case, in the present invention, the density and characteristics (color tone) of the generated image are measured, the density difference and the color difference from the expected value are calculated from the measured value, and the deviation amount from the expected value is calculated. In addition, there is provided a method and means capable of feeding back the deviation to the exposure amount and performing correction.
[0073]
[Example 1: Description of detailed configuration and operation of the present invention] (Example of all-color measurement)
This will be described with reference to FIGS.
[0074]
3, the display unit 4, the operation unit 5, the panel control unit 6, and the display information storage unit 7 constitute a GUI 200. The panel control means 6 reads the display information stored in the display information means 7 in advance in accordance with the key set by the power supply or the operation means 5 and causes the display means 4 to display the screen. The operator looks at the display means 4 and can visually perform selection, setting, and input operations with the operation means 5 using a marker or the like. Hereinafter, the selection, setting, and input operations are performed by the operation unit 5.
[0075]
When the power is turned on, the panel control means 6 reads the main screen of FIG. 10A from the display information storage means 7 and displays it (Step S1: FIG. 4; hereinafter, the steps are omitted and denoted by S numbers). When the operator selects the setting of FIG. 10A, the measurement screen of FIG. 10B is displayed. Here, a color patch (sample), special color, and ink setting screen appears. However, in this example, since all colors are measured unless a specific instruction is given, the description will be made as is with all colors. The data at the top of the screen in FIG. 10B displays the Y, M, and C densities, L *, a *, and b * characteristic values for the measured color after measurement.
[0076]
The control unit 8 that has received the measurement instruction from the panel control unit 6 controls the measurement device 1 (corresponding to the acquisition device or the acquisition unit or the measurement unit in the claims) to obtain L * for all colors of the target print. , A * and b * are measured (S2 in FIG. 4). Before measurement, it is desirable to set the measurement device calibration shown in FIG. 10B and calibrate the measurement device. In FIG. 3, when the undercolor of the overprint is not emphasized or the ink setting is not adjusted in the all-color measurement, the processing directly enters the rendering unit 10. If no rendering is performed, the data is input to the conversion means 11 (in the case of NO in FIG. 4). The parameter calculation means 9 and the rendering means 10 (S3 to S5 in FIG. 4) in FIG. 3 will be described later.
[0077]
The conversion means 11 reads the previously stored density characteristic file (S100 in FIG. 4) from the storage means 13 and measures the density characteristic file in the coordinate space of the density characteristic file, that is, as shown in FIG. L *, a *, and b * are applied, and converted into concentrations Dy, Dm, and Dc decomposed into Y, M, and C corresponding to the measured L *, a *, and b * (S6 in FIG. 4). If the measured L *, a *, and b * do not match the L *, a *, and b * of the density characteristic file, the L *, a *, and b * of the density characteristic file closest to the measured L *, a *, and b * Dy, Dm, and Dc may be determined by using the values of L *, a *, and b * instead. Further, it can be obtained by calculating from a plurality of data close to L *, a *, b * of the measured target printed matter. As a specific method, there is a method of determining how changes in L *, a *, and b * affect Dy, Dm, and Dc by multiple regression, and estimating from the results. By going through the conversion means, a prototype of the color correction table is completed.
[0078]
The machine difference correction unit 12 converts the density of the basic color of the specific group image output device (reference device) stored in advance or density data serving as a standard of the basic color into standard data (standard data of claim 10; The density is stored as S200 in FIG. 4 and the standard data is used to correct the density due to variations in the characteristics of the exposure unit. When an LED is used as an exposure device, as described in JP-A-2002-72367, there is a phenomenon in which the maximum emission wavelength shifts due to a drive current, and this characteristic varies depending on the device, and the device emits light even when the same drive current flows. The amount fluctuates. Collectively treating these characteristics as machine differences is advantageous from the viewpoint of simplification of the mechanism.
[0079]
The standard data (sometimes referred to as machine difference data) is obtained by performing development processing after exposing a photosensitive material with a prescribed exposure amount in the same manner as creating a photosensitive material characteristic table, measuring the density of the obtained patches, A table can be created as a correspondence between the density of the device and the density of the device to be evaluated (or the difference thereof).
[0080]
The numerical values in the respective columns of the color correction table created by the conversion means 11 are corrected for machine differences by the machine difference correction means 12, and the color correction table is completed.
[0081]
The storage unit 13 stores the color correction table in which the machine difference has been corrected by the machine difference correction unit 12, and supplies the color correction table to the output of the next proof image (S8 in FIG. 4). FIG. 8 shows an example of a color correction table created by measuring all colors in this way. In addition, the storage unit 13 stores machine difference correction data, a density characteristic file, and the like, and may be configured by one memory or a plurality of memories.
[0082]
The data of the color correction table may be transferred to the proof image output device 1 together with the image data from the halftone data generation unit 15, or may be transferred in advance and stored in the proof image output device 1. .
[0083]
Since the halftone dot data generation unit 15 forms a halftone dot and forms an image with a plurality of pixels within the area of the halftone dot as described above, the halftone dot and pixel data (information for identifying the coordinate position) The control unit 8 controls each unit, and as a result, the color correction for determining and controlling the exposure means for each halftone dot and each pixel. A table is created (when the density is converted into a light amount according to the characteristics of the photosensitive material, a table in which the light amount is determined for each pixel is created).
[0084]
(Nose calculation means 9 and its screen)
There are two ways to use spot colors. When a special color ink image is overprinted on a process ink image (this may be called a "noise"), the process ink image is eliminated and only the special color image is printed. (This may be called a nuki). In the case of non-colored ink, it is sufficient to consider the color of the special color ink, but in the case of loose, it is necessary to consider the characteristics of the ink.
[0085]
The parameter (nose) calculating means 9 (hereinafter referred to as nose calculating means 9) in the above description is used for this nose as follows.
[0086]
(A) Used when calculating L *, a *, and b * for colors not measured by the measuring device 3 by calculation. In FIG. 4, nose is performed (S3 in FIG. 4), conditions are specified on the display screen, and nose calculation is performed by the nose calculation means 9 (S3b in FIG. 4).
[0087]
(B) In light of the proof purpose of estimating the finish of printing, firstly, it is desired that the finish be similar to printing. However, when ink with low transparency is overprinted on top, it may be advantageous to use a proof that is reproduced with high transparency because it makes it easier to determine the status of the underlying image. That is, in the case where the underprinting is specified and the undercolor is visually recognized and operated, and the plate inspection is enabled as a result (S4-YES, S4a in FIG. 4), the GUI 200 shown in FIG. By reading the screen and selecting the color of the fog (lower color), it is possible to adjust the densities Dy, Dm, and Dc in the upper right of the screen as shown in the lower row. The designation is hidden on the screen of FIG. 10C, but can be adjusted by the operator by designating L *, a *, and b *. The designated L *, a *, and b * are added and subtracted together with the measured values by the parameter calculation means 9 (S4b in FIG. 4) and sent to the rendering means 10.
[0088]
(C) In calculating the reproduced color in the case of Nose, it is necessary to consider the characteristics of the ink. The main characteristic is the transparency of the ink, which is mainly determined by the overprinted ink (this is sometimes called the upper color), and the ink below the final color (this is sometimes called the lower color) ) Represents the magnitude of the contribution. Another important characteristic is the trapping rate, which depends on the combination of the upper and lower color inks and the printing order of the printing plate, and indicates the magnitude of the contribution of the upper color ink to the final color. It is preferable to consider other factors because the accuracy can be further improved, but it is preferable that the above two factors are considered when the effect is small and the work load is considered.
[0089]
The function is adjusted by reflecting these factors. The function is to output the screen of FIG. 10B or the screen of FIG. The Nose calculating means 9 calculates based on the set conditions and sends it to the rendering means 10 (S4-YES, S4a, 4b in FIG. 4). Details will be described later in the section of [Ink Settings].
[0090]
(Rendering means 10 and its screen)
In the correction by the rendering means 10, correction based on the quality of printing paper, correction of a preferable color tone based on a density range, and the like are performed. For example, when a proof image is formed using a silver halide photosensitive material having a silver halide emulsion layer capable of developing cyan, magenta, and yellow with respect to a target printed matter, there are differences in the properties of the colorants and the paper used. Due to such factors, it may not always be optimal for visual similarity to match the same density and color tone. The rendering unit 10 is a unit for adjusting the difference between the sheets and the like. As the paper, art paper, coated paper, mat paper, high quality paper, color high quality paper, and the like can be set.
[0091]
Since the screen shown in FIG. 10G is read out and displayed on the GUI 200, the operator can make adjustments and settings while viewing the screen. The adjusted and set information and parameters are measured by the measuring device 3 or calculated by the rendering means 10 together with L *, a *, and b * by the nose calculation means 9 and sent to the conversion means 11 (FIG. 4). S5-YES, S5a, S5b).
[0092]
Next, setting of paper and the like will be described.
[0093]
The setting of the printing paper can be set on the screen of FIG. 10G. However, a printed matter using high quality paper or the like as the printing paper has a low finish density and a relatively thin image is formed. In this case, in a proof of a silver halide light-sensitive material, an image approximated by numerical values of density and color tone may be an image having insufficient contrast. In that case, adjustment is made on the “rendering setting” screen to increase the contrast. Similarly, regarding the character quality of the K (black, black) color on the printed matter printed on the high quality paper, the area where the black plate image exists, that is, the contrast between the black color and the overprinted part, for the purpose of improving visibility. The operation for increasing the density is the low density correction in the “rendering setting” screen. In addition, it has a setting screen that can adjust the density of black independently.
[0094]
In many cases, almost desired results can be obtained by dividing the printing paper into three stages, that is, a group of art paper, a group of coated paper, a group of matte paper, and a group of high-quality paper. It is preferable to change the correction level according to the degree of coloring even for printing paper classified as the same high quality paper.
[0095]
Further, the transfer amount of the overcolor ink onto the printing paper or the transferred ink varies depending on the proof image output device 1, the ink, the printing conditions, and the like. Adjusting the calculation of the coloring amount in accordance with the trapping amount is trapping correction in the “rendering setting” screen.
[0096]
(Single color edit and edit means 14)
The editing means 14 in FIG. 3 is a function for finely adjusting the data of the color connection table individually. This is effective when readjusting a printed output (S10 and S12 in FIG. 4). A color to be adjusted is selected in a pull-down menu on the main screen in FIG. 10A and in FIG. 10D. On the screen of FIG. 10D, the target color tone of the printed matter, the color tone of the proof generated by the color correction table set by calculation, and the color tone simulating the color tone that fluctuates when the color correction table is adjusted therefrom Is displayed on the display means 4. The color tone is adjusted with the adjustment buttons on the screen while referring to the color tone, the output sample, and the target print. The color correction table is calculated based on the adjusted conditions, and after the calculation, recalculation is performed using this value (simulation calculation) and displayed (S12 in FIG. 4).
[0097]
(Measurement feedback)
The color after the proof is output is re-measured, and the color correction table is fed back to the proof image output device 1 based on the measured value and output again to check (or check and shift). This function is used for fine-tuning (if any), and can be executed and operated on the screen (sub-screen of the measurement screen) in FIG. 10H. This is mainly performed by the control unit 8.
[0098]
The color designated on the screen of FIG. 10H is selected from the proof image, and the density and the like are input. The density difference or color difference between the measured value and the calculated color was calculated, the deviation was calculated in the software, the difference was calculated as the difference between the values in the color correction table, and the difference was corrected. Re-output the color correction table.
[0099]
[Noise color operation]
Color of overprinted part that could not be measured
・ Properties of printing ink
・ Type of printing paper
・ Printing conditions, etc.
It can be generated by calculating based on the measured density or tone value according to
it can.
[0100]
By using the parameter (noise) calculation means 9 in FIG. 3, the number of X colors is measured from the target print, and L *, a *, and b * of the other colors are calculated (S3 in FIG. 4). -YES, S3a, S3b).
[0101]
Normally, in order to reproduce a color tone in which two or more colors of a printed material are superposed well by the color development of a silver halide light-sensitive material, each density of Y, M, and C required to reproduce each of the two colors independently. It cannot be reproduced with a simple sum of the components. In addition, in order to accurately control the exposure amount of the device, it is preferable to narrow the control range of the exposure amount. In this case, even if a desired color density is obtained, it may not be possible to realize this. This is likely to happen with overprinted colors. Therefore, in order to reproduce a color approximation to the overlapping color of the printing ink, light amount control according to a certain rule is required.
[0102]
In the present invention, with respect to the setting of the light quantity of the ink overlapping portion of the X color (X is an integer of 2 or more) in the printed matter, the newly generated first color and the second color that are newly overlapped in the printing order are set as one color. After that, the next superimposed color can be set based on the relationship between the newly set values of the first and second colors and the third color. The setting of a plurality of overprinting colors is performed by setting the newly generated first and second overlapping colors to be overlapped in the printing order as one color, and then setting the newly set first color and second color setting values and the third color. Therefore, the next color may be set, the first color and the second color may be set as lower colors, and the third color may be set as upper color.
[0103]
(Ink setting)
The setting of the ink can be set visually on the screen of FIG. 10F. When setting a color correction table of a target print product in which the fake color cannot be measured, a more accurate color correction table can be calculated by setting the components of ink used and ink in detail.
[0104]
The classification criteria are mainly classified into the following when the transparency of the ink, that is, the degree of transparency of the undercolor when overprinted, is divided.
[0105]
(B) Selection of ink type
・ Silver ink with low transparency containing metal pigment
・ Colored metallic ink with low transparency and containing metallic pigments
・ Normal ink Inks containing ordinary coloring pigments and dyes
In addition, the properties of the additive and the amount of the additive also affect the setting of the nose color. The following are types of additives.
・ Medium
・ White ink
[0106]
(B) Transparency of ink
The hue color varies depending on the ratio between the transparent component and the non-transparent component of the target printed color ink. Typical transparent components present in the ink composition include, for example, media, reducers, compounds and the like. The medium is a transparent colorless ink used for adjusting the saturation and density and imparting gloss.
[0107]
Compound is a general term for various products for improving printability by mixing with ink, and is an auxiliary agent used for lowering ink tackiness and the like. The reducer is an additive called a waist-cutting agent used for lowering the viscosity of the ink and adjusting the tack. Other transparent components include varnishes, and opaque components include commercially available general inks in which pigments, dyes, metal powders, and the like are dispersed or dissolved. Specifically, Space Color Barius G, Barius G ES, Barius G ER, Barius G for calibration, Die Spark, NCP Silver, etc., manufactured by Dainippon Ink and Chemicals, or TK High Unity, manufactured by Toyo Ink Manufacturing Co., Ltd. TK High Unity ON, TK High Unity Quick, TK High Echo, TKPD Echo, TK High Unity SOY, TK High Echo SOY1, and the like, but are not limited thereto. These inks can be used alone or in combination of two or more at an arbitrary ratio.
[0108]
(C) Ink transfer amount
Since this printing press prints a plurality of colors one after another at high speed, it is necessary to print the next color before the previously printed color naturally dries. As a result, the next color is applied while the ink is not completely dried, so that a phenomenon occurs in which the ink is not transferred 100%. This is called wet trapping. The rate at which the ink is transferred (trapping rate) increases as the transfer surface dries, and the trapping rate decreases when the other color is printed immediately before.
[0109]
By appropriately setting the exposure light amount of each overlapping color by reflecting this phenomenon of the target printed matter, and controlling the optimum color density of yellow, magenta, and cyan, a more approximate proof image can be obtained.
[0110]
A silver halide photosensitive material having a silver halide emulsion layer capable of emitting at least cyan, magenta, and yellow on a support of a light-sensitive material can be arbitrarily changed in amount using a light source having a different wavelength based on digital data. In the method of forming a gradation image to be subjected to color development after image exposure, it is impossible to set a density exceeding each of the maximum color densities (Dmax) of yellow, magenta, and cyan. Setting is required.
[0111]
[Example 2]
In the first embodiment, the configuration has been described with an example in which all colors are measured. However, by using the parameter (nose) calculating means 9 in FIG. 3, a predetermined number of colors (for example, 18 ), L *, a *, and b * of other colors can be obtained. Further, when the parameter calculating means 9 calculates the color characteristics of a color that has not been obtained based on the obtained overprinted color, the lower color of the overlap, and the upper color of the overlap, the upper color obtained by the calculation is calculated. It is also possible to calculate (predict) the color characteristics of a color that has not been acquired using the characteristics of the color inks, and thereby, there is a characteristic that a large amount of data can be obtained with a small amount of measurement data. In addition, the ink characteristics of the upper color obtained by the calculation are stored and accumulated for each ink type, and the color characteristics of the color not acquired are calculated using the ink characteristics of the upper color newly obtained by the calculation. Each time, the ink characteristics can be updated as a specific ink characteristic and the accuracy can be improved.
An example of an operation for obtaining a color correction table (hereinafter, the “color correction table” may be referred to as “color correction” and the value thereof may be referred to as “color correction value”) for the color not measured after the above-described ink setting will be described below.
[0112]
As a method of creating a color correction table reflecting the transparency and the trapping rate, a method using the following equation 1 can be used. That is, the color correction value Dj can be obtained by the following equation 1.
Dj = Aj (U, O) × Oj + Bj (O) × Uj Equation 1
Here, j represents a color material (here, three types of Y, M, and C) forming a proof image, A is a trapping rate, B is the transparency of the ink on the overprinted portion, and Uj is the overprinted portion. Undercolor color correction value, Oj: Overprinted color correction value of upper color. The reason why j is not added in the function display for A and B is that this is determined by the type of ink.
[0113]
FIG. 9 shows an example of calculating a color correction table from the values of A and B and the characteristic data of 18 colors. FIG. 9 measures the density indicated in the “measured value of 18 colors” in the upper right column, and based on the measured value and the “coefficient relating to the ink transparency” and the “coefficient relating to the trapping rate” in the upper left column, The “calculated collection table” in the lower right column of FIG. 9 is obtained by calculation for the 48 colors.
[0114]
Hereinafter, a specific example of calculating the color correction value of the overprinted color in a specific printing order will be described with reference to FIGS.
[0115]
(Calculation method example 1)
FIG. 11 shows, for example, in the case where the printing order of the printed matter of the ink is C → M → Y, K → C → M → Y, etc., from the monochromatic color correction values of K, C, M, Y using the above-described formula 1. FIG. 9 shows a calculation order, K, C, M, and Y single-color color correction values, a transmittance, a trapping rate, and a printing color calculation result when color correction values of overprinted colors are sequentially obtained. The output sample obtained as a result of the overprint calculation is designated as Sample 1. The color components of K, C, M, and Y are represented by y, m, and c.
[0116]
In the following description, for example, Dy (M + Y) corresponds to the density of the proof color material y in a portion where the ink M is overprinted with the ink M. Dc (K + M + Y) corresponds to the density of the proof color material c in the portion where the inks K, M, and Y are overprinted.
[0117]
When the printing order is, for example, C → M → Y, the printing order of FIG. As shown in FIG. 8, first, based on the monochromatic color correction value of the y component of C, the y component of the trapping rate A, the y component of the transparency B, and the monochromatic color correction value of the y component of the second color, M, are used in Equation 1. A compliant operation is performed to obtain a color correction value Dy (C + M) of the y component of (C + M). Next, based on the color correction value Dy (C + M) of the y component of (C + M), similarly, using the values of the y component related to Y of the third color, an operation based on Equation 1 is performed, and (C + M + Y) ), The color correction value Dy (C + M + Y) of the y component is obtained. Dm (C + M + Y) and Dc (C + M + Y) are also obtained in the same manner as described above.
[0118]
When the printing order is, for example, K → M → Y, the printing order of FIG. As shown in FIG. 8, Dy (K + M + Y), Dm (K + M + Y), and Dc (K + M + Y) are obtained.
[0119]
FIG. 13 shows a case where the calculation result in the lower column of FIG. No. 1 to No. The state of presence of K, C, M, and Y in each sample up to 16 is indicated by a black frame.
[0120]
(Example 2 of calculation method)
FIG. 14 shows, for example, the color correction values of the overprinted colors in order from the single color correction values of K, C, M, and Y using the above equation 1 when the printing order of the printed material of the ink is C → M → Y → K. It shows the calculation order, K, C, M, and Y single-color color correction values, transmittance, trapping rate, and the result of overprinting calculation. The output sample obtained as a result of the overprint calculation is designated as Sample 2. No. in this case. 8, No. FIG. 16 shows a calculation method for 13 samples.
[0121]
FIG. 17 shows the case where the calculation result in the lower column of FIG. No. 1 to No. The state of presence of K, C, M, and Y in each sample up to 16 is indicated by a black frame.
[0122]
When the image of Sample 1 obtained in Calculation Method Example 1 was compared with Printed Material 1 actually created in the same printing order, an image free from discomfort was obtained as a whole. There was a shift in the overall color tone from the printed matter 2.
[0123]
The image of the sample 2 obtained in the calculation method example 2 was an image without any discomfort as a whole when compared with the printed matter 2 created in the same printing order, but the overall color tone was compared with the printed matter 1. Was displaced. FIG. 15 shows the results of these studies.
[0124]
From the above, it was found that the image of the sample 1 based on the color correction value obtained by the calculation corresponding to the printing order as in the present invention approximates the actual printed matter.
[0125]
(Calculation method example 3)
FIG. 18 shows, for example, when the printing order of the printed matter of the ink is K → C → M → Y → special color 1 (S) → special color 2 (T), the single-color color correction values of K, C, M, Y, S, T , Transmittance (predicted value), and trapping rate (predicted value). Special color 1 is gold-red ink, and special color 2 is blue-gold ink.
[0126]
Further, for example, Dm (C + T) corresponds to the density of the proof color material m in a portion where the special color 2 (T) is overprinted on the ink C.
[0127]
No. in this case. 13, No. 29, no. No. 45, and no. FIG. 21 shows calculation method 3 for 61 samples. FIG. No. 1 to No. The presence state of K, C, M, Y, S, and T in each of the samples up to 64 is indicated by a black frame.
[0128]
Using the calculation method example 3 based on the data shown in FIG. 18, color correction values were calculated and output for all combinations of 64 colors in the overprinting to obtain a sample 3. The average ΔE was calculated based on the same 64 colors of the sample 3 and the actual printed matter.
[0129]
A patch of a printed matter in which the special color 2 (T) (blue gold) was overprinted on Y was actually measured to obtain a color correction value. From the measured data, the transmittance and the trapping rate of the ink of the special color 2 were predicted and corrected as shown in FIG.
[0130]
Based on the data shown in FIG. 19, a sample 4 was obtained by outputting in the same manner as described above, and the average ΔE was calculated. FIG. 20 shows a comparison between Sample 3 and Sample 4.
[0131]
As described above, a higher-precision image can be obtained when at least one overprinted color is measured.
[0132]
In addition, five samples were measured for the tracing rate and transparency of the blue gold ink used in the calculation method example 3, and the average values were obtained. The average values were stored as the tracing rate and the transparency of the blue gold ink, and these values were stored. When the proof output was performed by using, the color difference ΔE was small and a good image was obtained.
[0133]
As described above, it is possible to improve the reproducibility of the overprinted color by configuring the color characteristics of the overprinted color in accordance with the printing order and sequentially calculating while feeding back the previous calculation result. Also, when calculating the above printing order, you can set the transparency and trapping rate so that the upper color and the lower color can be identified when they are actually printed. Becomes easier.
[0134]
The technology in the above description is limited, and the equivalent scope thereof is not limited to the described technology but belongs to the technical idea of the present invention.
[0135]
【The invention's effect】
According to the configuration described above, according to the present invention, it is possible to realize a digital color proof capable of obtaining a high-quality proof image corresponding to the printing order of ink.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining halftone dots and pixels in an image.
FIG. 2 is a diagram showing an overall configuration.
FIG. 3 is a diagram showing a functional configuration according to the present invention.
FIG. 4 is a diagram illustrating an operation flow of the functional configuration of FIG. 3;
FIG. 5 is a diagram illustrating an example of a photosensitive material (photosensitive material) characteristic table.
FIG. 6 is a view for conceptually explaining a density characteristic file.
FIG. 7 is a diagram showing a combination of a light amount and a density.
FIG. 8 is a color correction table created by measuring all colors in Example 1.
FIG. 9 is a color correction table created by calculation in the first embodiment.
FIG. 10A is a diagram showing an example of a screen by a GUI, and is a diagram showing a main screen.
FIG. 10B is a diagram showing a screen example by a GUI, and is a diagram showing a measurement screen.
FIG. 10C is a diagram illustrating an example of a screen by a GUI, and is a diagram illustrating a loose color selection screen.
FIG. 10D is a diagram showing an example of a screen by a GUI, showing a selection screen of a color to be adjusted;
FIG. 10E is a diagram showing an example of a screen by a GUI, and is a diagram showing an edit screen.
FIG. 10F is a diagram showing a screen example by a GUI, and is a diagram showing an ink setting screen.
FIG. 10G is a diagram showing a screen example by a GUI, and is a diagram showing a print paper setting screen.
FIG. 10H is a view showing an example of a screen by a GUI, and is a view showing a measurement feedback screen.
FIG. 11 is a diagram illustrating a calculation order, a single-color color correction value, a transmittance, a trapping rate, and a calculation result of color printing when obtaining color correction values in the order of ink printing.
FIG. 12 is a diagram illustrating a calculation method example 1;
FIG. 13 is a diagram showing the presence state of K, C, M, and Y in each sample of Calculation Method Example 1 by a black frame.
FIG. 14 is a diagram illustrating a calculation order, a single-color color correction value, a transmittance, a trapping rate, and a calculation result of overprinting when obtaining color correction values in the order of ink printing.
FIG. 15 is a diagram showing evaluation results of Sample 1 and Sample 2.
FIG. 16 is a diagram illustrating a calculation method example 2;
FIG. 17 is a diagram showing the state of presence of K, C, M, and Y in each sample of Calculation Method Example 2 by a black frame.
FIG. 18 is a diagram illustrating a single-color color correction value including a special color, a transmittance, and a trapping rate when a color correction value is obtained in the order of ink printing.
FIG. 19 is a diagram illustrating a monochrome color correction value, a transmittance, and a trapping rate corrected by predicting a transmittance and a trapping rate for a special color ink from actual measurement data.
FIG. 20 is a diagram showing evaluation results of Sample 1 and Sample 2.
FIG. 21 is a diagram illustrating a calculation method example 2;
FIG. 22 is a diagram showing the presence state of K, C, M, and Y in each sample of Calculation Method Example 3 by a black frame.
FIG. 23A is a diagram for explaining conversion into an exposure amount for each pixel;
FIG. 23B is a diagram for explaining conversion into an exposure amount for each pixel;
FIG. 24 is a diagram showing a flow of conversion into an exposure amount for each pixel.
FIG. 25 is a diagram showing the notation of a color represented by ink used in the description of the present invention.
[Explanation of symbols]
1 Proof image output device
2 Target printed matter
3 Measurement means (acquisition means)
4 Display means
5 Operating means
6 Panel control
7. Display information storage means
8 Control part
9 Parameter calculation means (Nose calculation means)
10 Rendering means
11 Conversion means
12 Machine difference correction means
13 Storage means
15 Halftone data generator
100 Image information processing device
100a CPU
100b memory
200 GUI

Claims (11)

An image information processing method for processing image data of a printed matter in order to reproduce and output a color obtained by printing a plurality of colors by a proof image output device,
An obtaining step of obtaining and outputting a color characteristic for specifying a predetermined color including the plurality of colors,
Based on the color characteristics obtained in the obtaining step, based on the color characteristics, the calculating step of calculating the color characteristics of the overprint color formed by overprinting the plurality of colors in the order of the overprint,
With reference to a density characteristic table of the color characteristics versus the basic color density of the proof image output device prepared in advance, the color characteristics output in the acquisition step and the color characteristics calculated in the calculation step are converted. Converting the density of each of the basic colors,
A storage step of storing the density of the basic color obtained in the conversion step,
Outputting the data of the table stored in the storage step to the proof image output device and printing the data. The calculating step includes sequentially calculating, for each of the colors that are overprinted to form the overprinted color, the color characteristics of the color that is formed by overprinting the color, thereby obtaining the color characteristics of the overprinted color. 2. The image information processing method according to claim 1, wherein Storing the color characteristics of the color sequentially calculated in the calculation step,
The calculating step calculates a color characteristic of a color formed by printing another color on the color based on the stored color characteristic of the color,
3. The image information processing method according to claim 2, wherein: The calculation step is based on a color characteristic of the color to be overprinted and a color under the color, a trapping rate according to the color and the lower color, and a transparency of the color. 4. The image information processing method according to claim 2, wherein the color characteristic of a color formed by overprinting is calculated. A proof image output device capable of reproducing a color obtained by printing a plurality of colors and outputting a printed material, and obtaining a color characteristic capable of specifying a predetermined color including the plurality of colors Connected to the device,
With reference to a density characteristic table of the color characteristics of the proof image output device prepared in advance versus the basic color density, the color characteristics of the predetermined color acquired by the acquisition device are converted into density data of a basic color, An image information processing apparatus that outputs the converted density data of the basic color to the proof image output apparatus and prints the density data,
GUI means capable of performing display for inputting the order of the overprinting of the plurality of colors when outputting the printed matter,
An operation for calculating the color characteristics of the overprinted color formed by overprinting the plurality of colors in the order of the overprint input based on the GUI means based on the color characteristics acquired by the acquisition device. Means,
Referring to the density characteristic table of the color characteristics versus the basic color density, the color characteristics of the predetermined color output by the acquisition device and the color characteristics of the overprint color calculated by the calculation unit are calculated. Converting means for converting and obtaining density data of each of the basic colors;
Storage means for storing density data of the basic color obtained by the conversion means for sending to the proof image output device;
An image information processing apparatus comprising: An image forming method for reproducing a color in which a plurality of colors are overprinted by a proof image output device and forming an area grayscale image as an aggregate of a plurality of halftone dots,
A preparatory step of acquiring a basic color density vs. light amount characteristic for performing exposure by the proof image output device in advance;
An obtaining step of obtaining and outputting a color characteristic for specifying a predetermined color including the plurality of colors,
Based on the color characteristics obtained in the obtaining step, based on the color characteristics, the calculating step of calculating the color characteristics of the overprint color formed by overprinting the plurality of colors in the order of the overprint,
With reference to a density characteristic table of the color characteristics versus the basic color density of the proof image output device prepared in advance, the color characteristics output in the acquisition step and the color characteristics calculated in the calculation step are converted. Converting the density of each of the basic colors,
An output step of outputting pixel information for identifying a pixel;
On the basis of the pixel information output in the output step, referring to the basic color density vs. light quantity characteristic acquired in the preparation step, the light quantity in pixel units from the density of the basic color acquired in the conversion step And calculating
An image forming method, wherein an exposure amount by the proof image output device is controlled for each pixel to print out. The calculating step includes sequentially calculating, for each of the colors that are overprinted to form the overprinted color, the color characteristics of the color that is formed by overprinting the color, thereby obtaining the color characteristics of the overprinted color. 7. The image forming method according to claim 6, wherein is calculated. Storing the color characteristics of the color sequentially calculated in the calculation step,
The calculating step calculates a color characteristic of a color formed by printing another color on the color based on the stored color characteristic of the color,
8. The image forming method according to claim 7, wherein: The calculation step is based on a color characteristic of the color to be overprinted and a color under the color, a trapping rate according to the color and the lower color, and a transparency of the color. 9. The image forming method according to claim 7, wherein the color characteristic of a color formed by overprinting is calculated. An image output system including a proof image output device for printing a plurality of colors and outputting an area grayscale image as an aggregate of halftone dots as a plurality of pixels,
Storage means for storing a basic color density versus light amount characteristic for performing exposure by the proof image output device,
An obtaining unit that obtains and outputs color characteristics for specifying a predetermined color including the plurality of colors,
Calculating means for calculating the color characteristics of the overprint color formed by overprinting the plurality of colors in the order of the overprint based on the color characteristics acquired by the acquiring means;
Referring to a density characteristic table of the color characteristics versus the basic color density of the proof image output device prepared in advance, the color characteristics output by the acquisition unit and the color characteristics calculated by the calculation unit are converted. Conversion means for acquiring the density of each of the basic colors,
Pixel generation means for outputting pixel information for identifying a pixel,
On the basis of the pixel information output by the pixel generation unit, with reference to the basic color density vs. light amount characteristic stored by the storage unit, a pixel unit is obtained from the density of the basic color acquired by the conversion unit. Means for calculating the amount of light,
An image output system, wherein an amount of exposure by the proof image output device is controlled on a pixel-by-pixel basis based on the amount of light obtained by the calculation, and printout is performed. A proof image output device capable of reproducing a color obtained by printing a plurality of colors based on data corresponding to the density of a basic color and outputting a printed matter, and specifying a predetermined color including the plurality of colors. A computer program for performing desired printing by controlling a computer with an acquisition device for acquiring possible color characteristics,
Obtaining in advance a basic color density versus light amount characteristic for performing exposure by the proof image output device;
Performing a display for setting the order of the overprinting of the plurality of colors when outputting the printed matter;
Based on the color characteristics acquired by the acquisition device, in the order of the set overprint, calculating the color characteristics of the overprint color formed by overprinting the plurality of colors,
With reference to the density characteristic table of the color characteristics versus the basic color density prepared in advance, the color characteristics of the predetermined color acquired by the acquisition device, and the calculated color characteristics of the overprinted color are calculated. To obtain the density data of each of the basic colors,
Storing the density data of the basic color obtained by the conversion for sending to the proof image output device;
A computer program characterized by comprising:

Images