Image processing method and apparatus for converting colors in a color image

• US 20020145745A1
• Filed: 04/11/2002
• Published: 10/10/2002
• Est. Priority Date: 12/17/1993
• Status: Active Grant

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kanno, Akiko
• Granted Patent: US 6,927,877 B2
• Time in Patent Office: Days
• US Class Current: 358/1.9
• CPC Class Codes: H04N 1/6075 Corrections to the hue

Abstract

A color image signal is generated and an arbitrary color in the color image signal is set as a color to be converted. A color after conversion is designated. The color to be converted or a color similar to the color to be converted is converted into the color after conversion or a color similar to the color after conversion. By this processing, a good color-converted image in which a conversion boundary is unnoticeable.

Claims

1. A color image processing apparatus comprising:

means for generating a color image signal;

first color designation means for designating an arbitrary color in the color image signal as a color to be converted;

second color designation means for designating a color after conversion; and

color conversion means for converting the color to be converted or a color similar to the color to be converted into the color after conversion or a color similar to the color after conversion.

2. An apparatus according to claim 1, wherein said color image signal has values representing the hue, brightness and saturation of a color.

3. An apparatus according to claim 2, wherein each of said first and second color designation means designates the hue of the color.

4. An apparatus according to claim 3, wherein said similar color is a color having a hue positioned at a predetermined distance on Hue circle from the designated hue.

5. An apparatus according to claim 4, wherein the predetermined distance varies according to the designated hue.

6. An apparatus according to claim 1, wherein said color conversion means comprises a look-up table.

7. An apparatus according to claim 1, wherein said first and second color designation means comprise a pointing device.

8. An apparatus according to claim 1, further comprising read means for reading a color image.

9. An apparatus according to claim 8, wherein said color image signal is a signal read by said read means.

10. An apparatus according to claim 8, further comprising area designation means for designating a particular area on the color image.

11. An apparatus according to claim 8, wherein said color conversion means makes color conversion independently with respect to areas designated by said area designation means.

13. An apparatus according to claim 12, further comprising read means for reading a color image.

14. An apparatus according to claim 13, wherein the input image signal having plural components is a signal read by said read means.

15. An apparatus according to claim 13, further comprising area designation means for designating a particular area on the color image.

16. An apparatus according to claim 15, wherein said function conversion means makes conversion independently with respect to areas designated by said area designation means.

17. An apparatus according to claim 12, wherein functions for plural kinds of processing can be set in said function conversion means.

18. An apparatus according to claim 17, wherein said plural kinds of processing include color conversion.

19. An apparatus according to claim 17, wherein said plural kinds of processing include color space compression.

12. A color image processing apparatus comprising:

coordinate transformation means for converting an input image into three coordinates indicating the hue, saturation and brightness of a color;

function conversion means for converting an output from said coordinate transformation means by a predetermined function freely selected; and

coordinate reverse transformation means for reversely converting an output from said function conversion means into an image signal having said plural kinds of components.

20. A color image processing comprising:

supply means for supplying image signals having plural component including at least hue components and saturation components;

designation means for selecting particular one or all of the hue components and for designating the same as a hue to be adjusted;

setting means for setting a rate of change in at least one of a hue component and a saturation component of an image signal of the hue to be adjusted designated by said designation means.

21. An apparatus according to claim 20, wherein said designation means has, in an initial state, all the hue components set as a hue to be adjusted.

22. An apparatus according to claim 20, wherein said supply means converts an input signal of three primary colors into said plural components and supplies the converted components.

23. An apparatus according to claim 20, further comprising adjustment means for adjusting the level of the image signal having the hue to be adjusted according to the setting of said setting means.

24. An apparatus according to claim 23, wherein said adjustment means simultaneously adjusts the level of the hue component and the saturation component if the degree of adjustment has been set with respect to each of the hue component and the saturation component.

25. An apparatus according to claim 20, further comprising display means for displaying the state of designation made by designation means and the state of setting made by said setting means.

26. An apparatus according to claim 25, wherein said display means the state of designation and the state of setting in the same image.

27. An apparatus according to claim 20, further comprising area designation means for designating an area represented by an arbitrary one of the image signals having the plural kinds of components as an area with which a hue to be converted is designated by said designation means and with which a degree of change is set by said setting means.

28. An apparatus according to claim 27, wherein said area designation means designates at least one area as the designated area.

30. An apparatus according to claim 29, wherein said setting means is an operating unit of said color image processing apparatus.

31. An apparatus according to claim 29, wherein the area processing includes at least one of filtering processing and majority decision processing.

32. An apparatus according to claim 31, wherein said filtering processing is smoothing using a spatial filter.

33. An apparatus according to claim 29, wherein said determination means has equal color determination means which determines image data having the same color as a color previously designated in the processed image data having plural components.

35. An apparatus according to claim 34, wherein said setting means is an operating unit of said color image processing apparatus.

36. An apparatus according to claim 34, wherein the area processing includes at least one of filtering processing and majority decision processing.

37. An apparatus according to claim 36, wherein said filtering processing is smoothing using a spatial filter.

38. An apparatus according to claim 34, wherein said determination means has equal color determination means which determines image data having the same color as a color previously designated in the processed image data having plural components.

29. A color image processing apparatus comprising:

setting means for setting an area processing characteristic with respect to image data having plural components;

processing means for performing area processing with a characteristic selected according to the setting made by said setting means with respect to the image data having plural components; and

determination means for determining a color of the image data having plural components on the basis of the same image data processed by said processing means.

34. A color image processing apparatus comprising:

detection means for detecting the number of screen lines of a halftone dot image;

control means for controlling an area processing characteristic with respect to image data having plural components on the halftone dot image according to the result of detection made by said detection means;

processing means for processing the image data having plural components according to the area processing characteristic controlled by said control means; and

determination means for determining a color on the basis of the image data having plural components processed by said processing means.