Method, control device and non-transitory computer-readable storage medium storing program for estimating color verification result

Patent metadata

Field	Value
Publication number	US-9684856-B2
Application number	US-201615040759-A
Country	US
Kind code	B2
Filing date	Feb 10, 2016
Priority date	Feb 17, 2015
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

A control device estimates a color verification result by using the following method. The method includes obtaining a first set of color values by using measurements of a color chart printed by a printer without color management; calculating second and third sets of color values based on increased color gamut and reduced color gamut of the printer due to a conditional change of the printer; creating a first to third printer-profiles by using the first to third sets of color values; calculating theoretical reference values of target color values and first to third theoretical color values by using the first to third printer-profiles; calculating first to third color differences by using the theoretical reference values and the first to third theoretical color values; obtaining an estimated result of the color verification by comparing the first to third color differences with a preset standard value; and outputting the estimated result.

First claim

The invention claimed is:

1. A method used by a control device which performs color verification of colors printed by a printer, for estimating a result of the color verification, the color verification being judging of color reproduction accuracy of the printer, the method comprising:
causing a user to input conditions to be used for the color verification, through an input unit of the control device;
obtaining a first set of color values which is color measurement data obtained by measurement of a color chart printed by the printer without color management;
calculating a second set of color values and a third set of color values, wherein the second set of color values and the third set of color values are calculated based on the first set of color values and using data of device variation of the printer which is previously stored, such that calculation of the second set of color values and the third set of color values is performed without an additional printing of the color chart, wherein the second set of color values corresponds to the first set of color values and represents colors to be printed by the printer having a color gamut increased with a conditional change of the printer based on the previously stored data of device variation of the printer, and wherein the third set of color values corresponds to the first set of color values and represents colors to be printed by the printer having a color gamut reduced with a conditional change of the printer based on the previously stored data of device variation of the printer;
creating a first printer-profile, a second printer-profile and a third printer-profile by using the first set of color values, the second set of color values and the third set of color values;
on a basis of the conditions input by the user, calculating theoretical reference values of color values of a target of the color verification, by using a predetermined target profile;
calculating first theoretical color values, second theoretical color values and third theoretical color values from the theoretical reference values by using the first to third printer-profiles;
obtaining an estimated result of the color verification on a basis of comparison between a preset standard value and each of first to third color differences, the first to third color difference each representing a difference between the theoretical reference values and corresponding one of the first theoretical color values, the second theoretical color values and the third theoretical color values; and
outputting the estimated result through the output unit of the control device.

2. The method of claim 1 , wherein the causing a user to input the conditions includes causing the user to set at least a device type of the printer, a standard color to be used as the target, a paper type and a judgement level of color verification, as the conditions.

3. The method of claim 1 ,
wherein the calculating the second set of color values and the third set of color values includes:
defining, by using the previously stored data of device variation of the printer, a variation amount of color values corresponding to a probability of occurrence of the conditional change of the printer, and
calculating the second set of color values and the third set of color values by increasing the first set of color values by the variation amount and reducing the first set of color values by the variation amount, respectively.

4. The method of claim 3 , wherein:
the calculating the second set of color values and the third set of color values includes:
calculating the second set of color values and the third set of color values for each of plural probabilities of occurrence of conditional changes of the printer, and

the obtaining the estimated result includes:
for each of the plural probabilities, making an overall judgement of plural colors of interest, which are previously set, on a basis of comparison between the standard value and each of the first to third color differences for each of the plural colors of interest, and
estimating whether a result of the color verification indicates acceptable color reproduction accuracy or not, on a basis of results of the overall judgement for the plural probabilities.

5. The method of claim 4 , wherein the obtaining the estimated result includes:
calculating an acceptance ratio of the color verification, on a basis of a range of the probabilities for which the results of the overall judgement indicate acceptable color reproduction accuracy, and
estimating whether the result of the color verification indicates acceptable color reproduction accuracy or not, by comparing the acceptance ratio and a predetermined threshold.

6. The method of claim 4 , wherein the plural colors of interest are 100% cyan, 100% magenta, 100% yellow, 100% red, 100% green, 100% blue and 100% black.

7. The method of claim 4 , wherein the outputting the estimated result includes, if the estimated result indicates acceptable color reproduction accuracy, outputting the estimated result through the output unit and registering the conditions and the estimated result in a database with the conditions and the estimated result being associated with each other.

8. The method of claim 4 , wherein the outputting the estimated result includes, if the estimated result indicates unacceptable color reproduction accuracy, outputting the estimated result through the output unit, setting a flag to prohibit execution of color verification using the conditions, and registering the conditions, the estimated result and the flag in a database with the conditions, the estimated result and the flag being associated with each other.

9. The method of claim 8 , wherein:
the causing a user to input the conditions includes causing the user to set one of a plurality of judgement levels of color verification, as a condition to be used for the color verification, the plurality of judgement levels being defined according to the standard value, and
the outputting the estimated result includes, if the estimated result indicates unacceptable color reproduction accuracy, outputting the estimated result for each of the plurality of judgement levels through the output unit, and receiving a user's instruction to set another of the plurality of judgement levels as the condition to be used for the color verification, through the input unit.

10. The method of claim 8 , wherein the outputting the estimated result includes, if the estimated result indicates unacceptable color reproduction accuracy, outputting the estimated result for each of the colors of interest through the output unit, and receiving a user's instruction to change a setting of the standard value for each of the colors of interest through the input unit.

11. A control device which performs color verification of colors printed by a printer, where the color verification is judging of color reproduction accuracy of the printer, the control device comprising:
an input unit;
an output unit; and
a hardware processor that estimates a result of color verification and performs processing including:
causing a user to input conditions to be used for the color verification, through the input unit,
obtaining a first set of color values which is color measurement data obtained by measurement of a color chart printed by the printer without color management,
calculating a second set of color values and a third set of color values, wherein the second set of color values and the third set of color values are calculated based on the first set of color values and using data of device variation of the printer which is previously stored, such that calculation of the second set of color values and the

Assignees

• Konica Minolta Inc

Inventors

• Suzuki Naoyo

Classifications

• G06F3/1208

  resulting in improved quality of the output result, e.g. print layout, colours, workflows, print preview · CPC title

• H04N1/00045

  using a reference pattern designed for the purpose, e.g. a test chart · CPC title

• H04N1/6097

  depending on the characteristics of the output medium, e.g. glossy paper, matt paper, transparency or fabrics · CPC title

• H04N1/6027

  Correction or control of colour gradation or colour contrast (H04N1/6058 takes precedence) · CPC title

• H04N1/6033

  using test pattern analysis (H04N1/6055 takes precedence) · CPC title