COLOR PROCESSING METHOD AND APPARATUS

• US 20090052771A1
• Filed: 06/08/2006
• Published: 02/26/2009
• Est. Priority Date: 06/22/2005
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Ohga, Manabu
• Granted Patent: US 8,081,819 B2
• Time in Patent Office: Days
• US Class Current: 382/165
• CPC Class Codes: H04N 1/603 controlled by characteristics of the picture signal generator or the picture reproducer
• CPC Class Codes: H04N 1/6086 by scene illuminant, i.e. conditions at the time of picture capture, e.g. flash, optical filter used, evening, cloud, daylight, artificial lighting, white point measurement, colour temperature
• CPC Class Codes: H04N 1/6088 by viewing conditions, i.e. conditions at picture output

Abstract

In order to implement color matching with higher precision, a device that handles object colors and a device that handles light-source colors must be separately processed. Hence, when the device type is a device that handles light-source colors, control is made so as not to perform processing (forward color appearance model conversion and inverse color appearance model conversion) for converting calorimetric conditions of a calorimetric value file into viewing conditions. When the device type is a device that handles object colors, the processing for converting the calorimetric conditions of the calorimetric value file into the viewing conditions is performed, and a profile is created from the calorimetric values.

Claims

1. A method of performing color matching processing as correction processing using at least one viewing condition and at least one color conversion condition calculated from colorimetric values of a device, the method comprising the steps of:

obtaining the viewing condition;

converting of the colorimetric values which correspond to the colorimetric condition into colorimetric values which correspond to the viewing condition;

determining a type of the device; and

controlling performance of said converting step based on a determination result obtained in said determining step, wherein said controlling step includes of controlling the performance of said conversion step so as not to perform the conversion when the type of the device is a device that handles light-source colors, and controlling the performance of said conversion step so as to perform the conversion when the type of the device is a device that handles object colors.

2. The method according to claim 1, wherein said obtaining step includes obtaining a white point between a white point of the device and a white point of ambient light in a case of the device that handles light-source colors.

3. The method according to claim 1, wherein said converting step includes performing forward conversion according to the calorimetric condition and inverse conversion according to the viewing condition.

4. The method according to claim 1, wherein said controlling step includes of controlling performance of said converting step so as not to perform the conversion when the type of the device is the device that handles object colors and the calorimetric condition match the viewing condition.

5-8. -8. (canceled)

9. A computer-readable medium storing a computer program comprising program code for causing a computer to perform a method of performing color matching processing as correction processing using at least one viewing condition and at least one color conversion condition calculated from colorimetric values of a device, the method comprising the steps of:

obtaining the viewing condition;

converting the calorimetric values which correspond to the calorimetric condition into calorimetric values which correspond to the viewing condition;

determining a type of the device; and

controlling performance of said converting step based on a determination result obtained in said determining step, wherein said controlling step includes controlling the performance of said converting conversion step so as not to perform the conversion when the type of the device is a device that handles light-source colors, and controlling the performance of said converting step so as to perform the conversion when the type of the device is a device that handles object colors.

10-11. -11. (canceled)

12. A color processing apparatus for performing color matching processing as correction processing using at least one viewing condition and at least one color conversion condition calculated from calorimetric values of a device, comprising:

an obtainer, arranged to obtain the viewing condition;

a converter, arranged to convert the calorimetric values which correspond to the calorimetric condition into calorimetric values which correspond to the viewing condition;

a determiner, arranged to determine a type of the device; and

a controller, arranged to control said converter based on a determination result provided by said determiner, wherein said controller controls said converter so as not to perform the conversion when the type of the device is a device that handles light-source colors, and controls said converter so as to perform the conversion when the type of the device is a device that handles object colors.