Image processing device and method

• US 7,492,478 B2
• Filed: 06/21/2004
• Issued: 02/17/2009
• Est. Priority Date: 06/26/2003
• Status: Expired due to Fees

• Current Assignee: Fuji Xerox Company Limited (Xerox Holdings Corp.)
• Original Assignee: Fuji Xerox Company Limited (Xerox Holdings Corp.)
• Inventors: Une, Kiyoshi
• Primary Examiner(s): BURLESON, MICHAEL L
• Application Number:
  US10/871,042
• Publication Number:
  US 20040264772A1
• Time in Patent Office: 1,702 Days
• Field of Search: 358/1.9, 358/501, 358/518, 358/521, 382/162, 382/167
• US Class Current: 358/1.9
• CPC Class Codes: H04N 1/603 controlled by characteristics of the picture signal generator or the picture reproducer

Abstract

An image processing device including a storage unit which stores, for set moving-target-positions of a lightness or gray axis on an uniform color space in color balance correction, color correction parameters for performing color balance correction corresponding to moving the lightness or gray axis substantially parallel to a specific moving-target-position on the uniform color space to inputted color image data, and a correction unit which, when color balance correction to the target color image data is instructed via an instruction unit, reads a color correction parameter corresponding to the instructed color balance correction among the color correction parameters stored in the storage unit, to perform color balance correction to the target color image data using the read color correction parameter, is provided.

Claims

1. An image processing device comprising:

a storage unit that stores in advance a plurality of color correction parameters for performing color balance correction,

the color correction parameters corresponding to a plurality of set moving target positions of a lightness axis or a gray axis on an uniform color space, and

the color balance correction corresponding to only moving the lightness axis or the gray axis parallel to a specific moving target position selected from among a plurality of set moving target positions on the uniform color space with respect to inputted color image data; and

a correction unit that reads a color correction parameter and performs color balance correction,

the color correction parameter being read from among the plurality of the color correction parameters stored in the storage unit,

the correction unit reading the color correction parameter when instructed to do so by an instruction unit, and

the color balance correction being performed with respect to the color image data to be processed using the read color correction parameter.

2. The image processing device of claim 1, wherein the plurality of color correction parameters are stored so that distribution density of the set moving target positions in a first direction or a first region where fine adjustment of the color balance is necessary in the uniform color space becomes higher than that in directions or regions other than the first direction or the first region.

3. The image processing device of claim 1, wherein the first direction is a direction substantially along an a* axis in a color space of an L*a*b* color system serving as the uniform color space.

4. The image processing device of claim 2, wherein the first region includes a position, on the uniform color space, of a color corresponding to white in a display device that displays the color image data to be processed as an image.

5. The image processing device of claim 2, wherein the first region includes a position, on the uniform color space, of a color corresponding to white in a recording material that records thereon the color image data to be processed as an image.

6. The image processing device of claim 1, further comprising

a first conversion unit that uses a multidimensional look-up table to convert the inputted color image data to be processed to C, M and Y image data, to thereby simultaneously perform correction corresponding to characteristics of a recording unit that records the image data as an image on a recording material, and

a second conversion unit that uses a look-up table to perform conversion to C, M, Y and K image data and perform tone correction with respect to the C, M and Y image data subject to the conversion by the first conversion unit,

wherein the correction unit performs color balance correction with respect to the color image data to be processed by setting, in the multidimensional look-up table that the first conversion unit uses in conversion, a conversion parameter generated on the basis of the color correction parameter read from the storage unit.

7. The image processing unit of claim 1, wherein the instruction unit is configured to be able to instruct color balance correction by designating strength/weakness of hue to be emphasized.

8. The image processing unit of claim 1, wherein the instruction unit is configured to be able to instruct color balance correction by designating strength/weakness of hue to be attenuated.

10. The image processing device of claim 1, wherein the plurality of color correction parameters are stored so that distribution density of the set moving target positions in a first direction or a first region where fine adjustment of the color balance is necessary in the uniform color space becomes higher than that in directions or regions other than the first direction or the first region.

12. The image processing method of claim 10, wherein the first region includes a position, on the uniform color space, of a color corresponding to white in a display device that displays the color image data to be processed as an image.

13. The image processing method of claim 10, wherein the first region includes a position, on the uniform color space, of a color corresponding to white in a recording material that records thereon the color image data to be processed as an image.

17. The image processing device of claim 2, wherein the first region includes a position, on the uniform color space, of a predetermined color in a display device that displays the color image data to be processed as an image.

18. The image processing device of claim 2, wherein the first region includes a position, on the uniform color space, of a predetermined color in a recording material that records thereon the color image data to be processed as an image.

19. The image processing device of claim 2, wherein the first region includes a position, on the uniform color space, of a predetermined color.

9. An image processing method comprising:

setting a plurality of moving target positions of a lightness axis or a gray axis on a uniform color space;

storing in a storage unit a plurality of color correction parameters for performing color balance correction, the color correction parameters corresponding to the plurality of set moving target positions, and the color balance correction being performed by only moving the lightness axis or the gray axis parallel to a specific moving target position selected from among the plurality of set moving target positions on the uniform color space with respect to inputted color image data;

reading a color correction parameter from among the plurality of the color correction parameters stored in the storage unit when instructed to do so by an instruction unit; and

performing the color balance correction with respect to color image data to be processed using the read color correction parameter.

11. The image processing method of claim 9, wherein the first direction is a direction substantially along an a* axis in a color space of an L*a*b* color system serving as the uniform color space.

14. The image processing method of claim 9, further comprising

processing a first conversion in which, using a multidimensional look-up table, the inputted color image data to be processed is converted to C, M and Y image data, to thereby simultaneously perform correction corresponding to recording characteristics at a time of recording of the image data as an image on a recording material, and

processing a second conversion in which, using a look-up table, the C, M and Y image data subject to the first conversion is converted to C, M, Y and K image data and is performed tone correction,

wherein the color balance correction with respect to the color image data to be processed is performed with setting, in the multidimensional look-up table in processing the first conversion, a conversion parameter generated on the basis of the read color correction parameter.

15. The image processing method of claim 9, wherein the color balance correction can be instructed by designating strength/weakness of hue to be emphasized.

16. The image processing method of claim 9, wherein the color balance correction can be instructed by designating strength/weakness of hue to be attenuated.