Image processing method, apparatus, and program

• US 20040252907A1
• Filed: 04/19/2004
• Published: 12/16/2004
• Est. Priority Date: 10/26/2001
• Status: Active Grant

• Current Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Original Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Inventors: Ito, Tsukasa
• Granted Patent: US 7,308,152 B2
• Time in Patent Office: Days
• US Class Current: 382/260
• CPC Class Codes: H04N 1/58 Edge or detail enhancement; Noise or error suppression, e.g. colour misregistration correction H04N1/62 takes precedence

Abstract

An image processing method, having the steps of: transforming color image signals representing an original image into a luminance signal and color difference signals; transforming the luminance signal and the color difference signals separately into multi-resolution signals of the level 1 to the level N; applying an inverse multi-resolution transform to the color difference multi-resolution signals, after suppressing the high-frequency components of the level 1 of the color difference multi-resolution signals; applying an inverse multi-resolution transform processing to the luminance multi-resolution signals, after applying a coring processing using a condition for each level different from other levels to the high-frequency signals of each level of the luminance multi-resolution signals; transforming the processed luminance signal and the processed color difference signals into a set of processed color image signals.

Claims

1. An image processing method, comprising:

transforming a set of color image signals representing an original image into a luminance signal and color difference signals;

transforming the luminance signal and the color difference signals separately into multi-resolution signals of the level 1 to the level N to make them luminance multi-resolution signals and color difference multi-resolution signals;

applying an inverse multi-resolution transform to the color difference multi-resolution signals to make them processed color difference signals, after suppressing the high-frequency components of the level 1 of the color difference multi-resolution signals;

applying an inverse multi-resolution transform processing to the luminance multi-resolution signals to make them a processed luminance signal, after applying a coring processing using a condition for each level different from other levels to the high-frequency signals of each level of the luminance multi-resolution signals;

transforming the processed luminance signal and the processed color difference signals into a set of processed color image signals.

3. The image processing method of claim 1, wherein the set of color image signals representing an original image are digital image signals obtained by the scanning of a dye image formed on a silver halide film.

5. The image processing method of claim 1, wherein the coring processing to the luminance multi-resolution signals includes at least one processing which is practiced under a non-linear coring condition such that the rate of change for the signal values of the higher rank corresponding to at least 5% to the total number of signal values with respect to the absolute value of an input signal becomes smaller than 10%, and for the signal values of the lower rank corresponding to at least 15% to the total number become substantially zero.

7. The image processing method of claim 1, wherein the condition for the coring processing of the luminance multi-resolution signals of the level n is changed with reference to a high-frequency signal of a higher level than n.

9. The image processing method of claim 1, wherein the condition for the coring processing of a luminance multi-resolution signal of the level n is such one as to preserve the low-frequency signal of each level generated in a multi-resolution transform, and to be changed with reference to the low-frequency signal of the level n.

11. The image processing method of claim 1, wherein the condition for the coring processing of a luminance multi-resolution signal of the level n is such one as to preserve the low-frequency signal of each level generated in the multi-resolution transform, and to be changed with reference to a low-frequency signal of a level higher than n.

13. The image processing method of claim 1, wherein luminance low-frequency signals and color difference low-frequency signals of each level generated in a multi-resolution transform of the luminance signal and the color difference signals are preserved;

the condition of a photographic object is judged with reference to one or more of the luminance low-frequency signals, the color difference low-frequency signals, and a luminance high-frequency signal; and

the condition of the coring processing is changed on the basis of the result of the judgement.

15. The image processing method of claim 1, further comprising the step of applying a gradation transform to the luminance low-frequency image signal of the highest level, before applying the inverse multi-resolution transform processing.

17. The image processing method of claim 1, further comprising the step of applying a gray-balance adjustment to the color difference low-frequency image signals of the highest level, before applying the inverse multi-resolution transform.

2. An image processing method, comprising:

transforming a set of color image signals representing an original image into a luminance signal and color difference signals;

transforming the luminance signal and the color difference signals separately into multi-resolution signals of the level 1 to the level N to make them luminance multi-resolution signals and color difference multi-resolution signals;

applying an inverse multi-resolution transform to the color difference multi-resolution signals to make them processed color difference signals, after suppressing the high-frequency components of the level 1 of the color difference multi-resolution signals;

applying an inverse multi-resolution transform processing to the luminance multi-resolution signals to make them a processed luminance signal, after applying a coring processing using a condition for each level different from other levels to the high-frequency signals of each level of the luminance multi-resolution signals;

applying a sharpness enhancement processing to the processed luminance signal to make it a luminance signal of enhanced sharpness;

transforming the luminance signal of enhanced sharpness and the processed color difference signals into a set of processed image signals.

4. The image processing method of claim 2, wherein the set of color image signals representing an original image are digital image signals obtained by the scanning of a dye image formed on a silver halide film.

6. The image processing method of claim 2, wherein the coring processing to the luminance multi-resolution signals includes at least one processing which is practiced under a non-linear coring condition such that the rate of change for the signal values of the higher rank corresponding to at least 5% to the total number of signal values with respect to the absolute value of an input signal becomes smaller than 10%, and for the signal values of the lower rank corresponding to at least 15% to the total number become substantially zero.

8. The image processing method of claim 2, wherein the condition for the coring processing of the luminance multi-resolution signals of the level n is changed with reference to a high-frequency signal of a higher level than n.

10. The image processing method of claim 2, wherein the condition for the coring processing of a luminance multi-resolution signal of the level n is such one as to preserve the low-frequency signal of each level generated in a multi-resolution transform, and to be changed with reference to the low-frequency signal of the level n.

12. The image processing method of claim 2, wherein the condition for the coring processing of a luminance multi-resolution signal of the level n is such one as to preserve the low-frequency signal of each level generated in the multi-resolution transform, and to be changed with reference to a low-frequency signal of a level higher than n.

14. The image processing method of claim 2, wherein luminance low-frequency signals and color difference low-frequency signals of each level generated in a multi-resolution transform of the luminance signal and the color difference signals are preserved;

the condition of a photographic object is judged with reference to one or more of the luminance low-frequency signals, the color difference low-frequency signals, and a luminance high-frequency signal; and

the condition of the coring processing is changed on the basis of the result of the judgement.

16. The image processing method of claim 2, further comprising the step of applying a gradation transform to the luminance low-frequency image signal of the highest level, before applying the inverse multi-resolution transform processing.

18. The image processing method of claim 2, further comprising the step of applying a gray-balance adjustment to the color difference low-frequency image signals of the highest level, before applying the inverse multi-resolution transform.

19. An image processing apparatus comprising:

a first transforming device for transforming a set of color image signals, representing an original image, into a luminance signal and color difference signals;

a second transforming device for transforming the luminance signal and the color difference signals separately into multi-resolution signals of the level 1 to the level N to make them luminance multi-resolution signals and color difference multi-resolution signals;

a third transforming device for applying an inverse multi-resolution transform to the color difference multi-resolution signals to transform them into processed color difference signals, after suppressing high-frequency signals of the level 1 of said color difference multi-resolution signals;

a coring processing device for applying a coring processing using a condition for each level different from other levels to high-frequency signals of each level of the luminance multi-resolution signals;

a fourth transforming device for applying an inverse multi-resolution transform to the luminance multi-resolution signals, having already undergone the coring processing, to transform them into a processed luminance signal; and

a fifth transforming device for transforming the processed luminance signal and the processed color difference signals into a set of processed color image signals.

21. The image processing apparatus of claim 19, wherein the set of color image signals representing an original image are digital image signals obtained by the scanning of a dye image formed on a silver halide film.

23. The image processing apparatus of claim 19, wherein the coring processing device includes at least one processing means which performs under a non-linear coring condition such that the rate of change for the signal values of the higher rank corresponding to at least 5% to the total number of signal values with respect to the absolute value of an input signal becomes smaller than 10%, and for the signal values of the lower rank corresponding to at least 15% to the total number become substantially zero.

25. The image processing apparatus of claim 19, wherein the condition for the coring processing of the luminance multi-resolution signals of the level n is changed with reference to a high-frequency signal of a higher level than n.

27. The image processing apparatus of claim 19, wherein the condition for the coring processing of a luminance multi-resolution signal of the level n is such one as to preserve the low-frequency signal of each level generated in a multi-resolution transform, and to be changed with reference to the low-frequency signal of the level n.

29. The image processing apparatus of claim 19, wherein the condition for the coring processing of a luminance multi-resolution signal of the level n is such one as to preserve the low-frequency signal of each level generated in the multi-resolution transform, and to be changed with reference to a low-frequency signal of a level higher than n.

31. The image processing apparatus of claim 19, further comprising:

a preserving device for preserving luminance low-frequency signals and color difference low-frequency signals of each level generated in a multi-resolution transform of the luminance signal and the color difference signals;

a judgment device for judging the condition of a photographic object with reference to one or more of the luminance low-frequency signals, the color difference low-frequency signals, and a luminance high-frequency signal; and

a condition changing device for changing the condition of the coring processing on the basis of the result of the judgment.

33. The image processing apparatus of claim 19, further comprises a gradation transforming device for applying a gradation transform to the luminance low-frequency image signal of the highest level, before applying the inverse multi-resolution transform.

35. The image processing apparatus of claim 19, further comprises a gray-balance adjusting device for applying a gray-balance adjustment to the color difference low-frequency image signals of the highest level before applying the inverse multi-resolution transform.

20. An image processing apparatus comprising:

a first transforming device for transforming a set of color image signals representing an original image into a luminance signal and color difference signals;

a second transforming device for transforming the luminance signal and the color difference signals separately into multi-resolution signals of the level 1 to the level N to make them luminance multi-resolution signals and color difference multi-resolution signals;

a third transforming device for applying an inverse multi-resolution transform to the color difference multi-resolution signals to transform them into processed color difference signals, after suppressing high-frequency signals of the level 1 of said color difference multi-resolution signals;

a coring processing device for applying a coring processing using a condition for each level different from other levels to high-frequency signals of each level of the luminance multi-resolution signals;

a fourth transforming device for applying an inverse multi-resolution transform to the luminance multi-resolution signals, having already undergone the coring processing, to transform them into a processed luminance signal;

a sharpness enhancing device for applying a sharpness enhancement processing to the processed luminance signal to make it a luminance signal of enhanced sharpness; and

a fifth transforming device for transforming the luminance signal of enhanced sharpness and the processed color difference signals into a set of processed color image signals.

22. The image processing apparatus of claim 20, wherein the set of color image signals representing an original image are digital image signals obtained by the scanning of a dye image formed on a silver halide film.

24. The image processing apparatus of claim 20, wherein the coring processing device includes at least one processing means which performs under a non-linear coring condition such that the rate of change for the signal values of the higher rank corresponding to at least 5% to the total number of signal values with respect to the absolute value of an input signal becomes smaller than 10%, and for the signal values of the lower rank corresponding to at least 15% to the total number become substantially zero.

26. The image processing apparatus of claim 20, wherein the condition for the coring processing of the luminance multi-resolution signals of the level n is changed with reference to a high-frequency signal of a higher level than n.

28. The image processing apparatus of claim 20, wherein the condition for the coring processing of a luminance multi-resolution signal of the level n is such one as to preserve the low-frequency signal of each level generated in a multi-resolution transform, and to be changed with reference to the low-frequency signal of the level n.

30. The image processing apparatus of claim 20, wherein the condition for the coring processing of a luminance multi-resolution signal of the level n is such one as to preserve the low-frequency signal of each level generated in the multi-resolution transform, and to be changed with reference to a low-frequency signal of a level higher than n.

32. The image processing apparatus of claim 20, further comprising:

a preserving device for preserving luminance low-frequency signals and color difference low-frequency signals of each level generated in a multi-resolution transform of the luminance signal and the color difference signals;

a judgment device for judging the condition of a photographic object with reference to one or more of the luminance low-frequency signals, the color difference low-frequency signals, and a luminance high-frequency signal; and

a condition changing device for changing the condition of the coring processing on the basis of the result of the judgment.

34. The image processing apparatus of claim 20, further comprises a gradation transforming device for applying a gradation transform to the luminance low-frequency image signal of the highest level, before applying the inverse multi-resolution transform.

36. The image processing apparatus of claim 20, further comprises a gray-balance adjusting device for applying a gray-balance adjustment to the color difference low-frequency image signals of the highest level before applying the inverse multi-resolution transform.

41. The program of claim 34, wherein the coring processing device includes at least one processing means which performs under a non-linear coring condition such that the rate of change for the signal values of the higher rank corresponding to at least 5% to the total number of signal values with respect to the absolute value of an input signal becomes smaller than 10%, and for the signal values of the lower rank corresponding to at least 15% to the total number become substantially zero.

37. A program for making a computer function as an image processing apparatus, the image forming apparatus comprising:

a first transforming device for transforming a set of color image signals, representing an original image, into a luminance signal and color difference signals;

a second transforming device for transforming the luminance signal and the color difference signals separately into multi-resolution signals of the level 1 to the level N to make them luminance multi-resolution signals and color difference multi-resolution signals;

a third transforming device for applying an inverse multi-resolution transform to the color difference multi-resolution signals to transform them into processed color difference signals, after suppressing high-frequency signals of the level 1 of said color difference multi-resolution signals;

a coring processing device for applying a coring processing using a condition for each level different from other levels to high-frequency signals of each level of the luminance multi-resolution signals;

a fourth transforming device for applying an inverse multi-resolution transform to the luminance multi-resolution signals, having already undergone the coring processing, to transform them into a processed luminance signal; and

a fifth transforming device for transforming the processed luminance signal and the processed color difference signals into a set of processed color image signals.

39. The program of claim 37, wherein the set of color image signals representing an original image are digital image signals obtained by the scanning of a dye image formed on a silver halide film.

43. The program of claim 37, wherein the condition for the coring processing of the luminance multi-resolution signals of the level n is changed with reference to a high-frequency signal of a higher level than n.

45. The program of claim 37, wherein the condition for the coring processing of a luminance multi-resolution signal of the level n is such one as to preserve the low-frequency signal of each level generated in a multi-resolution transform, and to be changed with reference to the low-frequency signal of the level n.

47. The program of claim 37, wherein the condition for the coring processing of a luminance multi-resolution signal of the level n is such one as to preserve the low-frequency signal of each level generated in the multi-resolution transform, and to be changed with reference to a low-frequency signal of a level higher than n.

49. A program of claim 37, wherein the image processing apparatus further comprises:

a preserving device for preserving luminance low-frequency signals and color difference low-frequency signals of each level generated in a multi-resolution transform of the luminance signal and the color difference signals;

a judgment device for judging the condition of a photographic object with reference to one or more of the luminance low-frequency signals, the color difference low-frequency signals, and a luminance high-frequency signal; and

a condition changing device for changing the condition of the coring processing on the basis of the result of the judgment.

51. The program of claim 37, wherein the image processing apparatus further comprises a gradation transforming device for applying a gradation transform to the luminance low-frequency image signal of the highest level, before applying the inverse multi-resolution transform.

53. The program of claim 37, wherein the image processing apparatus further comprises a gray-balance adjusting device for applying a gray-balance adjustment to the color difference low-frequency image signals of the highest level before applying the inverse multi-resolution transform.

38. A program for making a computer function as an image processing apparatus, the image forming apparatus comprising:

a first transforming device for transforming a set of color image signals representing an original image into a luminance signal and color difference signals;

a second transforming device for transforming the luminance signal and the color difference signals separately into multi-resolution signals of the level 1 to the level N to make them luminance multi-resolution signals and color difference multi-resolution signals;

a third transforming device for applying an inverse multi-resolution transform to the color difference multi-resolution signals to transform them into processed color difference signals, after suppressing high-frequency signals of the level 1 of said color difference multi-resolution signals;

a coring processing device for applying a coring processing using a condition for each level different from other levels to high-frequency signals of each level of the luminance multi-resolution signals;

a fourth transforming device for applying an inverse multi-resolution transform to the luminance multi-resolution signals, having already undergone the coring processing, to transform them into a processed luminance signal;

a sharpness enhancing device for applying a sharpness enhancement processing to the processed luminance signal to make it a luminance signal of enhanced sharpness; and

a fifth transforming device for transforming the luminance signal of enhanced sharpness and the processed color difference signals into a set of processed color image signals.

40. The program of claim 38, wherein the set of color image signals representing an original image are digital image signals obtained by the scanning of a dye image formed on a silver halide film.

42. The program of claim 38, wherein the coring processing device includes at least one processing means which performs under a non-linear coring condition such that the rate of change for the signal values of the higher rank corresponding to at least 5% to the total number of signal values with respect to the absolute value of an input signal becomes smaller than 10%, and for the signal values of the lower rank corresponding to at least 15% to the total number become substantially zero.

44. The program of claim 38, wherein the condition for the coring processing of the luminance multi-resolution signals of the level n is changed with reference to a high-frequency signal of a higher level than n.

46. The program of claim 38, wherein the condition for the coring processing of a luminance multi-resolution signal of the level n is such one as to preserve the low-frequency signal of each level generated in a multi-resolution transform, and to be changed with reference to the low-frequency signal of the level n.

48. The program of claim 38, wherein the condition for the coring processing of a luminance multi-resolution signal of the level n is such one as to preserve the low-frequency signal of each level generated in the multi-resolution transform, and to be changed with reference to a low-frequency signal of a level higher than n.

50. A program of claim 38, wherein the image processing apparatus further comprises:

a preserving device for preserving luminance low-frequency signals and color difference low-frequency signals of each level generated in a multi-resolution transform of the luminance signal and the color difference signals;

a judgment device for judging the condition of a photographic object with reference to one or more of the luminance low-frequency signals, the color difference low-frequency signals, and a luminance high-frequency signal; and

a condition changing device for changing the condition of the coring processing on the basis of the result of the judgment.

52. The program of claim 38, wherein the image processing apparatus further comprises a gradation transforming device for applying a gradation transform to the luminance low-frequency image signal of the highest level, before applying the inverse multi-resolution transform.

54. The program of claim 38, wherein the image processing apparatus further comprises a gray-balance adjusting device for applying a gray-balance adjustment to the color difference low-frequency image signals of the highest level before applying the inverse multi-resolution transform.