Image processing apparatus, image processing method, and image processing system

• US 6,128,407 A
• Filed: 05/12/1997
• Issued: 10/03/2000
• Est. Priority Date: 05/13/1996
• Status: Expired due to Fees

• Current Assignee: Fuji Xerox Company Limited (Xerox Holdings Corp.)
• Original Assignee: Fuji Xerox Company Limited (Xerox Holdings Corp.)
• Inventors: Higashikata, Ryousuke, Ogatsu, Hitoshi, Inoue, Takahide
• Primary Examiner(s): Couso, Jose L.
• Assistant Examiner(s): Dang, Duy M.
• Application Number:
  US08/855,841
• Time in Patent Office: 1,240 Days
• Field of Search: 382/162, 382/167, 382/232, 382/166, 358/504, 358/518, 358/501, 358/519, 358/580, 358/530, 358/448, 395/101, 395/109, 395/131
• US Class Current: 382/167
• CPC Class Codes: G06T 11/001 Texturing; Colouring; Generation of texture or colour inpainting G06T5/77
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 7/90 Determination of colour characteristics
• CPC Class Codes: H04N 1/6058 Reduction of colour to a range of reproducible colours, e.g. to ink- reproducible colour gamut

Abstract

An image processing apparatus is disclosed which comprises:

means for inputting image data,

color distribution recognition means for recognizing a color distribution in a color space and position information in an image space of the image data input through the input means, and

means for determining one or more color reproduction parameters of the image data based on the color distribution and position information recognized by the color distribution recognition means and a color reproduction range of an output device.

Claims

1. An image processing apparatus comprising:

means for inputting image data,

color distribution recognition means for recognizing a color distribution in a color space and position information in an image space of the image data input through said input means, and

means for determining one or more color reproduction parameters of the image data based on the color distribution and position information recognized by said color distribution recognition means and a color reproduction range of an output device.

2. An image processing apparatus comprising:

means for inputting image data,

color distribution recognition means for recognizing a color distribution of the image data input through said input means,

grouping means for grouping the color distribution recognized by said color distribution recognition means into one or more groups, and

means for determining a color reproduction parameter of the image data based on the groups into which the color distribution is grouped by said grouping means and a color reproduction range of an output device.

3. The image processing apparatus of claim 2, wherein

said color distribution recognition means divides the color space into areas and counts the number of pixels belonging to each division area, and

said grouping means determines whether or not adjacent areas can be combined based on the counts of the adjacent areas provided by said color distribution recognition means and groups the areas in response to the determination result.

4. The image processing apparatus of claim 2, wherein

said color distribution recognition means divides the color space into areas, counts the number of pixels belonging to each division area, and recognizes pixel distribution information, and

said grouping means determines whether or not adjacent areas can be combined based on the counts of the adjacent areas provided by said color distribution recognition means and the pixel distribution information, and groups the areas in response to the determination result.

5. The image processing apparatus of claim 2, wherein said grouping means groups the areas except for color distributions of portions where no degradation of color discrimination is assumed to occur.

6. The image processing apparatus of claim 2, wherein

said color reproduction parameter determination means comprises:

gradation determination means for determining spread magnitude of color change of the group for determining the color reproduction parameter based on the determination result of said gradation determination means.

7. The image processing apparatus of claim 2, wherein

said color reproduction parameter determination means determines a color compression method and color compression strength for the group based on a distribution form of a portion where a color portion space on the color space contained in the group is outside the color reproduction range.

8. The image processing apparatus of claim 7, wherein

the color space is an equal color space, and

the distribution form is determined based on any one of spread in a lightness direction, spread in a hue direction, or spread in a chroma direction or combination thereof in the color portion space on the equal color space contained in the group.

9. The image processing apparatus of claim 2, wherein

said color reproduction parameter determination means determines a color compression method and color compression strength for the group based on a distribution form of a portion where a color portion space on the color space contained in the group is outside the color reproduction range and a distribution form of the group.

10. The image processing apparatus of claim 2, wherein

said color reproduction parameter determination means prepares one or more conversion parameters of a first equal color space to a second equal color space and one or more pieces of position mask information each indicating a position on the image space to which the conversion parameter is applied.

11. The image processing apparatus of claim 2, wherein

said color reproduction parameter determination means generates a group into which the groups are collected, and determines the color reproduction parameter for the group.

12. An image processing apparatus comprising:

means for inputting image data,

color distribution recognition means for recognizing a color distribution in a color space and position information in an image space of the image data input through said input means,

grouping means for grouping the color distribution into one or more groups based on the position information recognized by said color distribution recognition means, and

means for determining one or more color reproduction parameters of the image data based on the groups into which the color distribution is grouped by said grouping means and a color reproduction range of an output device.

13. The image processing apparatus of claim 12, wherein

said color distribution recognition means divides the color space into areas, counts the number of pixels belonging to each division area, and relates position information of pixels belonging to each area, and

said grouping means determines whether or not adjacent areas can be combined based on the counts of the adjacent areas provided by said color distribution recognition means, determines positions of the pixels belonging to the adjacent areas, and groups the areas on the color space in response to the two determination results.

14. The image processing apparatus of claim 12, wherein

said color reproduction parameter determination means generates a group into which the groups are collected, and determines a conversion parameter of a first equal color space to a second equal color space and position mask information indicating a position on the image space to which the conversion parameter is applied for the group.

15. An image processing method comprising the steps of:

recognizing a color distribution in a color space and position information in an image space of input image data, and

determining one or more color reproduction parameters of the image data based on the color distribution, the position information, and a color reproduction range of an output device.

16. The image processing method of claim 15, wherein

said color reproduction parameter determination step includes:

preparing one or more conversion parameters of a first equal color space to a second equal color space and one or more pieces of position mask information each indicating a position on the image space to which the conversion parameter is applied.

17. An image processing method comprising the steps of:

recognizing a color distribution of input image data,

grouping the recognized color distribution into one or more groups, and

determining a color reproduction parameter of the image data based on the groups and a color reproduction range of an output device.

18. The image processing method of claim 17, wherein

said color distribution recognition step divides the color space into areas, and counts the number of pixels belonging to each division area, and

said grouping step determines whether or not adjacent areas can be combined based on the counts of the adjacent areas provided by said color distribution recognition step, and groups the areas in response to the determination result.

19. The image processing method of claim 17, wherein

said color distribution recognition step divides the color space into areas, counts the number of pixels belonging to each division area, and recognizes pixel distribution information, and

said grouping step determines whether or not adjacent areas can be combined based on the counts of the adjacent areas provided by said color distribution recognition step and the pixel distribution information, and groups the areas in response to the determination result.

20. The image processing method of claim 17, wherein

said grouping step groups the areas except for color distributions of portions where no degradation of color discrimination is assumed to occur.

21. The image processing method of claim 17, wherein

said color reproduction parameter determination step includes:

determining a color compression method and color compression strength for the group based on a distribution form of a portion where a color portion space on the color space contained in the group is outside the color reproduction range.

22. The image processing method of claim 17, wherein

said color reproduction parameter determination step includes:

determining a color compression method and color compression strength for the group based on a distribution form of a portion where a color portion space on the color space contained in the group is outside the color reproduction range and a distribution form of the group.

23. An image processing method comprising the steps of:

recognizing a color distribution in a color space and position information in an image space of input image data,

grouping the color distribution into one or more groups based on the recognized position information, and

determining one or more color reproduction parameters of the image data based on the groups and a color reproduction range of an output device.

24. An image processing method comprising the steps of:

extracting areas on an image space made up of similar color pixels based on input image data and preparing clusters,

recognizing color distributions of the clusters and preparing a group, and

determining one or more color reproduction parameters of the image data based on the clusters, the group, and a color reproduction range of an output device.