Method of and apparatus for forming a color picture using a plurality of color correction processings

• US 4,631,578 A
• Filed: 02/27/1984
• Issued: 12/23/1986
• Est. Priority Date: 03/04/1983
• Status: Expired due to Term

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Sasaki, Takashi, Kawamura, Hideaki, Sakurada, Nobuaki
• Primary Examiner(s): Groody, James J.
• Assistant Examiner(s): Svihla, Randall S.
• Application Number:
  US06/583,735
• Time in Patent Office: 1,030 Days
• Field of Search: 358/80, 358/75, 358/78, 358/75 IJ, 346/140 R, 346/140 IJ, 346/140 PD, 364/526
• US Class Current: 358/518
• CPC Class Codes: H04N 1/6016 Conversion to subtractive colour signals
• CPC Class Codes: H04N 1/6027 Correction or control of colour gradation or colour contrast H04N1/6058 takes precedence

Abstract

In a method and apparatus for forming a high quality color picture, a color space is divided into several areas and the color correction processing is performed using a different color-correction function for every area. The disclosed method and apparatus are particularly adapted to eliminate false lines ("pseudo boundaries") in pictures formed using colorants having different concentrations or densities. The false lines or "pseudo boundaries" occur at points where a colorant of one concentration is replaced by a colorant of a different concentration, and are eliminated by switching between two color correction processing means corresponding to the two colorants of different concentrations in a mutually exclusive random or alternating manner.

Claims

1. Color picture forming method comprising the steps of:

inputting color input picture data;

forming a color picture using a plurality of colorants by selecting one of a plurality of combinations of colorants in response to the color input picture data;

providing a plurality of color correction processings corresponding to the plurality of combinations of colorants; and

selecting the color correction processing corresponding to the selected combination of colorants.

2. Color picture forming method according to claim 1, wherein said colorants comprise at least cyan, magneta, yellow, and black colorants.

3. Color picture forming method according to claim 2, wherein at least one of said colorants further comprises a plurality of colorants of different densities.

4. Color picture forming method according to claim 1, wherein in said forming step, the color picture is formed by an ink jet head.

5. Color picture data processing method comprising the steps of:

inputting color input picture data;

dividing a color space into a plurality of areas;

providing a corresponding color correction processing for each of said areas; and

selecting at least two of said color correction processings for the color input picture data in a mutually exclusive random of alternating manner.

6. Color picture forming method of reproducing a color picture in accordance with color input picture data using a plurality of colorants, comprising the steps of:

dividing a color space into a plurality of areas in dependence upon different combinations of colorants to be used;

providing a corresponding color correction processing for each of said plurality of areas; and

selecting at least two of said color correction processings for the color input picture data in a mutually exclusive random or alternating manner.

7. Color picture forming method according to claim 6, wherein said colorants comprise at least cyan, magenta, yellow, and black colorants.

8. Color picture forming method according to claim 7, wherein at least one of said colorants further comprises a plurality of colorants of different densities.

9. Color picture forming method comprising the steps of:

inputting color input picture data;

forming a color picture usuing a plurality of colorants;

providing a plurality of color correction processings corresponding to a plurality of combinations of colorants; and

selecting at least two of said color correction processings for the color input picture data in a mutually exclusive random or alternating manner.

10. Color picture forming method according to claim 9, wherein said colorants comprise at least cyan, magenta, yellow, and black colorants.

11. Color picture forming method according to claim 10, wherein at least one of said colorants further comprises a plurality of colorants of different densities.

12. Color picture forming method according to claim 9, wherein in said forming step, the color picture is formed by an ink jet head.

13. A color picture forming apparatus comprising:

color picture forming means for forming a color picture using a plurality of colorants;

a pluraltiy of processing means for performing color-correction processing of color input picture data;

selecting means for selecting at least two of said plurality of processing means in accordance with the color input picture data; and

switching means for switching between said selected processing means in a mutually exclusive random or alternating manner.

14. A color picture forming apparatus according to claim 13, wherein said colorants comprise at least cyan, magenta, yellow, and black colorants.

15. A color picture forming apparatus according to claim 14, wherein at least one of said colorants further comprises a plurality of colorants of different densities.

16. A color picture forming apparatus according to claim 13, wherein said color picture forming means includes an ink jet head.

17. Color picture forming method of reproducing a color picture, comprising the steps of:

inputting color input picture data;

providing colorants for a pluraltiy of different colors, wherein a plurality of colorants of different concentrations are provided for at least one of the different colors;

providing a plurality of different color correction processings corresponding to a pluraltiy of different combinations of said colorants; and

selecting one of said pluraltiy of different combinations of said colorants and a corresponding one of said plurality of different color correction processings in response to the color input picture data.