JP2007193418A - Image formation system and simulation support method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image formation system and a simulation support method for supporting selection of a paper sheet for carrying out simulation close to a printed result of a printing original sheet. <P>SOLUTION: This image formation system includes an image formation device for simulating a print output result in a printer of a target to be output, holds a color regeneration characteristic data generated based on an image formation result in the image formation means to each kind of the paper sheet, while correlated with the each of the plurality of kinds of paper sheets, calculates an evaluation value in every of the paper sheets, using the color regeneration characteristic data in every of the kinds of held paper sheets, when simulated, and exhibits selectively the kind of the paper sheet to be used, based on the evaluation value. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an image forming system including an image forming apparatus such as a printer and a simulation support method.

  In recent years, the performance of color printers has improved, and printing simulations on printing presses are sometimes performed using color printers. In such a printing simulation, it is easy to check the color reproducibility if the paper (printing paper) that is actually used in printing can be used, but the printing paper is not suitable for printing with a color printer. .

That is, there are cases where the printing paper is too thin or too thick to be transported from a paper tray or the like. Also, because the color materials used by color printers and printing presses are different, the color printing characteristics of color printers cannot be used with printing paper, and the reproducible color gamut is narrowed, reducing simulation accuracy. There is a case to do.
JP 2004-246465 A

  Therefore, if simulation is performed using paper suitable for image formation with a color printer, the color will be close, but if conditions such as glossiness differ, the impression received from the actual printing results on the printing press May be different.

  Japanese Patent Application Laid-Open No. 2004-228561 discloses a technique for performing a print simulation based on a user's printing environment, recommending an appropriate print sheet, and prompting the selection thereof.

  SUMMARY An advantage of some aspects of the invention is to provide an image forming system and a simulation support method for supporting paper selection for performing a simulation close to a printing result for a printing paper. .

  The present invention for solving the problems of the above conventional example is an image forming system, which simulates and outputs a print output result in a target printing machine, and each of a plurality of paper types. And holding means for holding color reproduction characteristic data generated based on the image formation result of the image forming means on each type of paper, and the paper type held at the time of the simulation Display means for calculating an evaluation value for each sheet using the color reproduction characteristic data for each sheet, and selectively presenting the type of the sheet to be used based on the evaluation value. .

  Here, the image forming unit forms an image in any one of a plurality of modes having different color development characteristics, and the holding unit stores color reproduction characteristic data in association with each of the plurality of modes for each paper type. The presenting means uses the color reproduction characteristic data for each of the held paper types, which is associated with the mode used for the simulation, during the simulation. Then, an evaluation value for each paper type may be calculated, and the paper type to be used may be selectively presented based on the evaluation value.

  Another embodiment of the present invention is a simulation support method using a computer connected to an image forming apparatus that simulates and outputs a print output result in a target printing machine, and each of a plurality of paper types The color reproduction characteristic data generated based on the image formation result of the image forming unit on each type of paper is held in association with the color, and the color for each of the held paper types is stored during the simulation. Using the reproduction characteristic data, an evaluation value for each paper is calculated, and based on the evaluation value, the type of paper to be used is selectively presented.

  Embodiments of the present invention will be described with reference to the drawings. As illustrated in FIG. 1, the image forming system according to the embodiment of the present invention includes a printer 1 as an image forming apparatus and a computer device (PC) 2 connected to the printer 1. .

  The printer 1 is a color printer, and forms an image on a set paper based on image data received from the computer apparatus 2. As long as the printer 1 of this embodiment is a color printer, it may be a laser printer or an inkjet printer, for example.

  The computer apparatus 2 includes a control unit 21, a storage unit 22, an operation unit 23, a display unit 24, a communication unit 25, and a colorimeter 26. Here, the control unit 21 is a CPU or the like, and operates according to a program stored in the storage unit 22. The control unit 21 according to the present embodiment performs a process of presenting a sheet to be used for simulation when receiving an instruction to simulate a printing result on the printing press. The contents of the processing of the control unit 21 will be described in detail later. In addition, the control unit 21 performs processing for sending image data to the printer 1 to perform image formation.

  The storage unit 22 includes a storage element such as a RAM (Random Access Memory) and a ROM (Read Only Memory), a disk device such as a hard disk, and the like. The storage unit 22 stores a program executed by the control unit 21. The storage unit 22 also operates as a work memory for the control unit 21. Furthermore, in this embodiment, the color reproduction data is held in the storage unit 22. This color reproduction data will also be described later.

  The operation unit 23 is a keyboard, a mouse, or the like, and outputs the content of the user's instruction operation to the control unit 21. The display unit 24 is a display or the like, and displays and outputs information according to an instruction input from the control unit 21. The communication unit 25 is an interface such as a USB and is connected to the printer 1. The communication unit 25 sends image data to the printer 1 in accordance with an instruction output from the control unit 21. The colorimeter 26 measures the color of the image formed on the paper, and outputs the color value (value in a predetermined color space) to the control unit 21.

  In the present embodiment, a predetermined color patch group is formed in advance by the printer 1 for each paper type that can be used, and the color patch group formed on each type of paper is read by the colorimeter 25, Color reproduction characteristic data is obtained, and this color reproduction characteristic data is stored in the storage unit 22. As a specific example, as shown in FIG. 2, the color reproduction characteristic data includes paper background color data and expression color gamut data associated with data specifying the paper type. Here, the data of the expression color gamut is expressed for each formed color patch when the difference between the color read by the colorimeter 26 and the color to be expressed is less than a predetermined threshold value. This is data that is a possible color, and when that is not the case, the color is an unrepresentable color. This data is, as a specific example, a list of colors determined to be expressible colors (hereinafter referred to as a paper expressible color list), and typically, as shown in FIG. 3, the printer 1 for each paper type. It is data that defines a gamut. The paper ground color data is a color value obtained by reading the ground color of the paper with the colorimeter 26, and is represented, for example, as a value in the L * a * b * color space.

  The user uses the colorimeter 26 to read the profile printing result on the target printing machine (printing machine to simulate the printing output result, hereinafter referred to as an actual machine). Here, the profile printing result is obtained by forming a color patch group corresponding to a plurality of predetermined color values on the printing paper. This color value includes white. That is, a color patch corresponding to white when printing with an actual machine is formed.

  The control unit 21 receives the input of the color value obtained by reading each of these color patches, and first calculates the white color in the actual machine and the paper ground color data of various papers included in the color reproduction characteristic data. Compare. In this comparison, a color value difference (color difference) ΔE is calculated, and an evaluation value V1 is calculated for each paper type using a function that is set to be lower as the color difference ΔE is larger, and the corresponding paper type is specified. The information is stored in the storage unit 22 in association with the information to be stored. Here, the function used for the calculation of the evaluation value V1 is, for example, a function that draws a curve as shown in FIG.

  Further, the control unit 21 acquires information on the color gamut that can be expressed when printing is performed on the actual printing paper from the color value information obtained by reading the profile printing result. This information is obtained when the difference between the color read by the colorimeter 26 and the color to be expressed is less than a predetermined threshold value for each color patch of the profile print result formed on the actual printing paper on the actual machine. Furthermore, the color is data that can be expressed, and otherwise the color that cannot be expressed. This data is also a list of colors determined to be expressible colors (hereinafter referred to as a target expressible color list) as a specific example, and is typically data that defines a gamut when printed on the actual printing paper. It is. Hereinafter, the gamut when printed on the printing paper with this actual machine is referred to as a target color gamut.

  The control unit 21 compares the target color gamut with the data of the expression color gamut for each paper type, and calculates a target content rate indicating how much the target color gamut and the expression color gamut overlap. As a specific example, a color patch group used to generate color reproduction characteristic data for each paper type and a color patch group used to generate target color gamut information are set as a color patch group of the same color, and a target expression The possible color list LT is compared with the paper expressible color list LP1, LP2,... Of the color patch group printed on each type of paper by the printer 1, and the colors included in the target expressible color list LT are: The ratio (content ratio) included in each paper expression color list LP1, LP2,... Is calculated for each paper type.

  Then, based on the content information for each paper type, an evaluation value V2 for each paper type is calculated using a function set so as to increase as the content rate increases, and the corresponding paper type is specified. The data are stored in the storage unit 22 in association. Here, the function used for the calculation of the evaluation value V2 is, for example, a function that draws a curve as shown in FIG.

Here, the content rate is calculated with a constant weight for the entire color gamut, but information on the color gamut to be emphasized (“red”, “low brightness”, etc.) is obtained in advance from the user, and the target expression is obtained. Of the colors included in the possible color list LT, the ratios (content ratios) of the colors corresponding to the color gamut to be emphasized are included in each paper expression color list LP1, LP2,... An evaluation value V2 corresponding to the rate may be obtained. Further, for example, when “red” is set to be emphasized, the content ratio calculation is weighted according to the degree of hue close to red (hue difference) among the colors included in the target expressible color list LT. May be. As an example, among the colors included in the target expressible color list LT, the hue difference from the color set to be emphasized for each of the color Cin included in the paper expression color list LP and the color Cout not included Using ε (Cin) and ε (Cout), the content ratio r is r = Σ (1 / ε (Cin)) / (Σ (1 / ε (Cin)) + Σ (1 / ε (Cout))
May be calculated. Here, Σ represents accumulating the reciprocal of ε for each Cin and Cout.

  Further, the control unit 21 evaluates whether the color gamut is insufficient or insufficient. That is, each of the paper expression color lists LP1, LP2,... Is sequentially set as the attention list, and among the colors included in the attention list LPi, the colors included in the attention list LPi but not included in the target expressible color list LT. The ratio of numbers (out-of-gamut ratio) is calculated, and the evaluation value V3 for each paper type is calculated using a function set so that the higher the out-of-gamut ratio, the lower the value, and the corresponding paper type is specified. The information is stored in the storage unit 22 in association with the information. Here, the function used for the calculation of the evaluation value V3 is a function for drawing a curve as shown in FIG. 6, for example. In this way, the evaluation of the lack of excess or deficiency in the color gamut is that if the color gamut of the printer 1 is wider than the color gamut of the actual machine, the actual machine will be solid (a color that uses 100% of a specific color material) This is because the color to be reproduced is shaded instead of 100% in the printer 1 and the texture may be different.

  In this way, the control unit 21 occupies the evaluation value V1 (hereinafter referred to as the background color evaluation value) relating to the difference between the paper background color and the white color when printing on the actual machine and the expressible color in the target expressible color list. An evaluation value V2 (hereinafter referred to as a content rate evaluation value) related to a ratio and an evaluation value V3 (hereinafter referred to as an overspec evaluation value) related to a ratio in which colors not included in the target expressible color can be expressed. ).

Based on these evaluation values, the control unit 21 calculates a comprehensive evaluation value V for each paper type, and stores it in the storage unit 22 in association with information for specifying the corresponding paper type. For example, if each evaluation value V1 to V3 is set as a value from “0” to “1”, the overall evaluation value V is
V = V1 × V2 × V3
It can be.

In addition, this comprehensive evaluation value weights each evaluation value,
V = α × V1 + β × V2 + γ × V3 (However, α + β + γ = 1 may be used)
It does not matter. In this way, by setting α, β, and γ, it is possible to set a more important evaluation value. For example, if the user can freely set α, β, and γ, the user who values the evaluation value V2 is important. Therefore, the value of β may be set larger than α and γ, and a user who places importance on the evaluation value V1 may set the value of α larger than β and γ.

  Further, for the content rate evaluation value V2, when the content rate is “0”, a function may be set so that the content rate evaluation value V2 is set to “0” (see FIG. 5). Further, if the content rate is less than a predetermined threshold value, the function may be set so that the content rate evaluation value V2 becomes “0”, assuming that the simulation cannot be performed.

  The control unit 21 sorts the comprehensive evaluation values V calculated for each paper type, for example, in descending order, and outputs information specifying the paper type having the highest comprehensive evaluation value V to the display unit 14.

  Since the image forming system of the present embodiment has the above-described configuration, when the user causes the colorimeter 26 to read a predetermined color patch group output on the actual printing paper with the actual machine, printing is performed from the color patch group with the actual machine. Information on white (target white) and information on the color gamut (target gamut) when it is output on the paper is calculated.

  Then, the color difference between the ground color information accumulated for each predetermined paper type and the target white information, the difference in the representable color gamut (the color reproducibility (content)) in the target gamut, The overall evaluation value V is calculated based on the color reproducibility ratio (over-spec portion) outside the target gamut, and the user is provided with information on the paper type having the highest overall evaluation value.

  As a result, the user can know the paper for performing the simulation close to the printing result for the printing paper, and can easily select the paper.

  In the description so far, the overall evaluation value V is calculated including the evaluation value V1 related to the difference between the paper ground color and the target white color. When performing a simulation method (so-called absolute simulation) for reproducing the background color of the image, the total evaluation value V is calculated based on the content rate evaluation value V2 and the overspec evaluation value V3 without using the evaluation value V1. Also good.

  When performing an absolute simulation in this way, the evaluation value Vx related to the difference between the paper ground color and a predetermined color (neutral color suitable for forming the ground color of the printing paper) is calculated, The comprehensive evaluation value V may be calculated based on the evaluation value Vx, the content rate evaluation value V2, and the overspec evaluation value V3. That is, this evaluation value Vx is an evaluation value that represents the reproducibility of the ground color of the printing paper.

  Further, the printer 1 may be able to form an image in any of a plurality of modes having different color development characteristics. For example, there are four color and six color modes in an ink jet printer, such as a high gloss mode and a high density mode. As described above, when a plurality of print modes can be selected in the printer 1, color reproduction characteristic data for each print mode is generated and held for each paper type.

  Then, the control unit 21 causes the user to select a print mode used for the simulation, and uses the color reproduction characteristic data for each paper type that is associated with the print mode to obtain the overall evaluation value V for each paper type. Calculate and output information specifying the paper type with the highest overall evaluation value. Further, when the simulation is performed, the control unit 21 outputs information specifying the print mode to the printer 1 together with the image data for simulation.

  Furthermore, instead of the evaluation value or in addition to the evaluation value, an evaluation value related to glossiness may be used. In this case, the glossiness of a representative color (such as a patch corresponding to a solid (100%) of each color material) is evaluated, and an evaluation value related to the average difference in glossiness of each color is calculated, and this evaluation value is comprehensively evaluated. You may use for the calculation of a value.

  The color reproduction characteristic data for each paper type can be obtained by printing a specific color patch on a paper of a type prepared by the user and measuring the color. That is, the user may arbitrarily add or delete the color reproduction characteristic data. Also in this case, when there are a plurality of print modes, the color printing characteristic data for each paper type and for each print mode is generated by measuring the result of printing in each print mode.

  Here, the PC 2 includes the color measuring device 26, but this is not always necessary, and the input of information obtained by reading the profile printing result with another color measuring device is received, and the total of each paper type is received. The evaluation value V may be calculated.

1 is a configuration block diagram illustrating an example of an image forming system according to an embodiment of the present invention. FIG. 5 is an explanatory diagram illustrating an example of holding color reproduction characteristic data in the image forming system according to the embodiment of the present invention. 4 is an explanatory diagram schematically showing a gamut represented by an expression color gamut of color reproduction characteristic data held by the image forming system according to the embodiment of the present invention. FIG. It is explanatory drawing showing the example of the function used for the calculation of the evaluation value V1 of the image forming system which concerns on embodiment of this invention. It is explanatory drawing showing the example of the function used for the calculation of evaluation value V2 of the image forming system which concerns on embodiment of this invention. It is explanatory drawing showing the example of the function used for the calculation of evaluation value V3 of the image forming system which concerns on embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Printer, 2 Computer apparatus, 21 Control part, 22 Memory | storage part, 23 Operation part, 24 Display part, 25 Communication part, 26 Colorimeter.

Claims (3)

Image forming means for simulating and outputting a print output result on a target printing machine;
Holding means for holding color reproduction characteristic data generated on the basis of the image formation result of the image forming means on each type of paper in association with each of a plurality of paper types;
During the simulation, an evaluation value for each sheet is calculated using the color reproduction characteristic data for each held sheet type, and a sheet type to be used is selectively selected based on the evaluation value. Presenting means to present to,
An image forming system comprising: The image forming system according to claim 1,
The image forming unit forms an image in any one of a plurality of modes having different color development characteristics.
The holding means holds color reproduction characteristic data in association with each of a plurality of modes for each paper type,
The presenting means uses the color reproduction characteristic data associated with the mode used in the simulation, which is the color reproduction characteristic data for each of the held paper types at the time of the simulation. An image forming system that calculates an evaluation value for each type and selectively presents a type of paper to be used based on the evaluation value. Using a computer connected to an image forming apparatus that simulates and outputs a print output result on a target printing machine,
In association with each of a plurality of paper types, color reproduction characteristic data generated based on the image formation result of the image forming unit on each type of paper is retained,
During the simulation, an evaluation value for each sheet is calculated using the color reproduction characteristic data for each held sheet type, and a sheet type to be used is selectively selected based on the evaluation value. A simulation support method characterized in that the simulation is presented.

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