Color image processing apparatus and method

• US 5,289,296 A
• Filed: 07/31/1991
• Issued: 02/22/1994
• Est. Priority Date: 08/02/1990
• Status: Expired due to Term

• Current Assignee: Canon Marketing Japan Incorporated (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Yamada, Masanori
• Primary Examiner(s): Coles, Sr., Edward L.
• Assistant Examiner(s): Grant II, Jerome
• Application Number:
  US07/738,563
• Time in Patent Office: 937 Days
• Field of Search: 358/75, 358/76, 358/79, 358/80, 358/81, 358/400, 358/401, 358/406, 358/443, 358/447, 358/448, 358/452, 358/453, 358/462, 358/464, 358/467, 358/468, 358/471, 358/474, 358/498
• US Class Current: 358/530
• CPC Class Codes: H04N 1/4072 dependent on the contents of the original
• CPC Class Codes: H04N 1/56 Processing of colour picture signals H04N1/52 takes precedence
• CPC Class Codes: H04N 1/62 Retouching, i.e. modification of isolated colours only or in isolated picture areas only

Abstract

A color image processing apparatus in which the background color of an original image to be read is determined by reading the color of a designated position on the original image, by selecting data on one of a plurality of colors previously stored in memory, or by automatically performing background color detection while reading the original image. When outputting the read original image, any of the individual read pixels of the original image coincident with the background color is output as a white pixel.

Claims

1. A color image processing apparatus, comprising:

input means for inputting color component data representing an original image;

detection means for detecting a background color of the original image;

judgment means for judging whether a portion of the original image other than an area having the background color is a monochromatic image or a multi-color image; and

process means for processing the color component data in accordance with the judgment result of said judgment means.

2. A color image processing apparatus according to claim 1, wherein said detection means includes:

position designation means for designating a position in the background portion of the original; and

color detection means for detecting color data on the designated position of the original image as the background color.

3. A color image processing apparatus according to claim 2, wherein said color detection means performs background color detection on the basis of color component data on a plurality of pixels in an area around the position on the original image designated by said position designation means, including the pixel of that position.

4. A color image processing apparatus according to claim 1, wherein said detection means includes:

memory means for storing data on a plurality of colors; and

selection means for selecting the data on one of the plurality of colors stored in said memory means as the background color.

5. A color image processing apparatus according to claim 4, further comprising registration means for registering background color data in said memory means.

6. A color image processing apparatus according to claim 1, further comprising reading means for reading an original image, and wherein said detection means comprises:

calculation means for calculating a value indicative of degree of brightness on the basis of color component data, R, G, B, on pixels read by said reading means;

first extraction means for extracting data on pixel having the maximum level of brightness of each of predetermined divisional areas of an original image; and

second extraction means for extracting data on pixel of the maximum frequency among the pixels extracted by said first extraction means;

the color component data R, G, B on the pixel extracted by said second extraction means being detected as the background color.

7. A color image processing apparatus according to claim 1, further comprising conversion means, which converts color component data R, G, B on a given pixel to data representing white when the color component data satisfies the following inequalities with respect to background color data Ro, Go, Bo:

space="preserve" listing-type="equation">Ro-Rm<

R<

Ro+Rm

space="preserve" listing-type="equation">Go-Gm<

G<

Go+Gm

space="preserve" listing-type="equation">Bo-Bm<

B<

Bo+Bm

(where Rm, Gm and Bm are fixed positive values).

8. The color image apparatus according to claim 1, wherein said monochromatic image is a black image.

9. A color image processing apparatus which processes input color component data and supplies it to a predetermined output apparatus, comprising:

input means for inputting color component data representing an original image;

detection means for detecting a background color of the original image;

conversion means for converting the color component data representing substantially the same color as the background color detected by said detection means into white data without converting the color component data representing other colors, and

output means for outputting the color component data converted by said conversion means.

10. A color image processing apparatus according to claim 9, wherein said output apparatus consists of a printer.

11. A color image processing apparatus according to claim 9, wherein said output apparatus consists of a facsimile apparatus connected to a telephone circuit.

12. A color image processing apparatus according to claim 9, wherein said detection means includes:

position designation means for designating a point in the background portion of the original image; and

color detection means for detecting color data on the designated position of the original image as the background color.

13. A color image processing apparatus according to claim 12, wherein said color detection means performs background color detection on the basis of color component data on a plurality of pixels in an area around the position designated by said position designation means, including the pixel of the designated position.

14. A color image processing apparatus according to claim 9, wherein said detection means includes:

memory means for storing data on a plurality of colors; and

selection means which selects data on one of the colors stored in said memory means as the background color.

15. A color image processing apparatus according to claim 14;

further comprising registration means for registering background color data in said memory means.

16. A color image processing apparatus according to claim 14, further comprising reading means for reading an original image and an original feeding means for feeding a plurality of original images successively to said reading means.

17. A color image processing apparatus according to claim 9, further comprising reading means for reading an original image, and wherein said detection means includes:

calculation means for calculating a value indicative of degree of brightness on the basis of color component data, R, G, B, on the pixels read by said reading means;

first extraction means for extracting data on the pixel having the maximum level of brightness of each of predetermined divisional areas of an original image; and

second extraction means for extracting data on the pixel of the maximum frequency among the pixels extracted by said first extraction means;

the color component data R, G, B on the pixel extracted by said second extraction means being detected as the background color.

18. A color image processing apparatus according to claim 17;

further comprising reading means for reading an original image and an original feeding means for feeding a plurality of original images successively to said reading means.

19. A color image processing apparatus according to claim 9, wherein said conversion means converts color component data R, G, B on a given pixel to data representing white when the color component data satisfies the following inequalities with respect to background color data Ro, Go, Bo:

space="preserve" listing-type="equation">Ro-Rm<

R<

Ro+Rm

space="preserve" listing-type="equation">Go-Gm<

G<

Go+Gm

space="preserve" listing-type="equation">Bo-Bm<

B<

Bo+Bm

(where Rm, Gm and Bm are fixed positive values).

20. The color image apparatus according to claim 9, wherein said monochromatic image is a black image.

21. A color image processing apparatus which reproduces a monochromatic original image in black component and which reproduces a multi-colored original image in a plurality of color components, said color image processing apparatus comprising:

reading means for reading an original image and generating color component data;

detection means for detecting a background color of the original image to be read;

conversion means for converting the color component data representing substantially the same color as the background color detected by said detection means into white data without converting the color component data representing other colors; and

reproduction means for reproducing an image by using the data converted by said conversion means.

22. A color image processing apparatus according to claim 21, wherein said detection means includes:

position designation means for designating a position in the background portion of the original image; and

color detection means for detecting color data on the designated position of the original image as the background color.

23. A color image processing apparatus according to claim 22, wherein said color detection means performs background color detection on the basis of color component data on a plurality of pixels in an area around the position designated by said position designation means, including the pixel of the designated position.

24. A color image processing apparatus according to claim 21, wherein said detection means includes:

memory means for storing data on a plurality of colors; and

selection means which selects data on one of the colors stored in said memory means as the background color.

25. A color image processing apparatus according to claim 24, further comprising registration means for registering background color data in said memory means.

26. A color image processing apparatus according to claim 24, further comprising original feeding means for feeding a plurality of original images successively to said reading means, said selection means being biased for each original.

27. A color image processing apparatus according to claim 21, wherein said detection means includes:

calculation means for calculating a value indicative of degree of brightness on the basis of color component data R, G, B on the pixels read by said reading means;

first extraction means for extracting data on the pixel having the maximum level of brightness of each of predetermined divisional areas of an original image; and

second extraction means for extracting data on the pixel of the maximum frequency among the pixels extracted by said first extraction means;

the color component data R, G, B on the pixel extracted by said second extraction means being detected as the background color.

28. A color image processing apparatus according to claim 27, further comprising an original feeding means for feeding a plurality of original images successively to said reading means.

29. A color image processing apparatus according to claim 21, wherein said conversion means converts color component data R, G, B on a given pixel to data representing white when the color component data satisfies the following inequalities with respect to background color data Ro, Go, Bo:

space="preserve" listing-type="equation">Ro-Rm<

R<

Ro+Rm

space="preserve" listing-type="equation">Go-Gm<

G<

Go+Gm

space="preserve" listing-type="equation">Bo-Bm<

B<

Bo+Bm

(where Rm, Gm and Bm are fixed positive values).

30. The color image apparatus according to claim 21, wherein said monochromatic image is a black image.

31. A color image processing apparatus comprising:

input means for inputting color component data representing an original image;

detection means for detecting a background color of the original image;

first judgment means for judging whether the original image including an area having the background color is a multi-color image or a monochromatic image;

second judgment means for judging whether a portion of the original image other than an area having the background color is a multi-color image or a monochromatic image;

selection means for selecting between said first and second judgment means; and

process means for processing the color component data in accordance with the judgment result of selected one of said first and second judgment means.

32. A color image processing apparatus according to claim 31, further comprising processing means for processing said input image in accordance with the judgement results obtained by said first or second judgment means selected by said selection means.

33. A color image processing apparatus according to claim 31, further comprising reading means which is adapted to scan originals to generate image data, said input image being supplied from said reading means.

34. The color image apparatus according to claim 31, wherein said monochromatic image is a black image.

35. A color image processing apparatus comprising:

input means for inputting color component data representing an original image;

detection means for detecting a background color of the original image;

first judgment means for judging whether the original image including an area having the background color is a multi-color image or a monochromatic image;

second judgment means for judging whether a portion of the original image other than an area having the background color is a multi-color image or a monochromatic image;

first mode setting means for setting a mode in which a judgment is not performed by said first and second judgment means; and

second mode setting means for setting a mode in which a judgment is performed by said second judgment means.

36. A color image processing apparatus according to claim 35, further comprising processing means for processing said input image in accordance with the judgement results obtained in the mode set by said first or second mode setting means.

37. A color image processing apparatus according to claim 35, further comprising reading means which is adapted to scan originals to generate image data, said input image being supplied from said reading means.

38. The color image apparatus according to claim 35, wherein said monochromatic image is a black image.

39. A color image processing method, comprising the steps of:

inputting color component data representing an original image;

detecting a background color of the original image;

judging whether a portion of the original image other than an area having a background color is a monochromatic image or a multi-color image; and

processing the color component data in accordance with the judgment result of said judging step.

40. A color image processing method according to claim 39, wherein said detection step includes:

designating a position in the background portion of the original; and

detecting color data on the designated position of the original image as the background color.

41. A color image processing method according to claim 40, wherein said color detection means performs background color detection on the basis of color component data on a plurality of pixels in an area around the position on the original image designated by said position designation means, including the pixel of that position.

42. A color image processing method according to claim 39, wherein said detection step includes:

storing data on a plurality of colors in a memory means; and

selecting the data on one of the plurality of colors stored in said memory means as the background color.

43. A color image processing method according to claim 42, further comprising registration step for registering background color data in said memory means.

44. The color image apparatus according to claim 39, wherein said monochromatic image is a black image.