Image processing method, apparatus, and program

• US 7,308,152 B2
• Filed: 10/22/2002
• Issued: 12/11/2007
• Est. Priority Date: 10/26/2001
• Status: Expired due to Fees

• Current Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Original Assignee: Konica Minolta Holdings Incorporated (Konica Minolta Inc.)
• Inventors: Ito, Tsukasa
• Primary Examiner(s): Do; Anh Hong
• Application Number:
  US10/493,194
• Publication Number:
  US 20040252907A1
• Time in Patent Office: 1,876 Days
• Field of Search: 382/260, 382/162, 382/166, 382/248, 382/249, 382/250, 382/173, 375/240.23, 375/240.14
• 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 level 1 to level N to produce luminance multi-resolution signals and color difference multi-resolution signals;

applying an inverse multi-resolution transform to the color difference multi-resolution signals to produce processed color difference signals, after suppressing 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 produce a processed luminance signal, after 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;

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

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

3. 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 a rate of change for signal values of a higher rank corresponding to at least 5% of a total number of signal values with respect to an absolute value of an input signal becomes smaller than 10%, and a rate of change for signal values of a lower rank corresponding to at least 15% of the total number becomes substantially zero.

4. 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.

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

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

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

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

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

8. The image processing method of claim 1, further comprising:

applying a gradation transform to a luminance low-frequency image signal of a highest level, before applying the inverse multi-resolution transform processing.

9. The image processing method of claim 1, further comprising:

applying a gray-balance adjustment to color difference low-frequency image signals of a highest level, before applying the inverse multi-resolution transform.

10. 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 level 1 to level N to produce luminance multi-resolution signals and color difference multi-resolution signals;

applying an inverse multi-resolution transform to the color difference multi-resolution signals to produce processed color difference signals, after suppressing 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 produce a processed luminance signal, after 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;

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

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

11. The image processing method of claim 10, wherein the set of color image signals representing the original image are digital image signals obtained by scanning of a dye image formed on a silver halide film.

12. The image processing method of claim 10, 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 a rate of change for signal values of a higher rank corresponding to at least 5% of a total number of signal values with respect to an absolute value of an input signal becomes smaller than 10%, and a rate of change for signal values of a lower rank corresponding to at least 15% of the total number becomes substantially zero.

13. The image processing method of claim 10, 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.

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

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

16. The image processing method of claim 10, wherein luminance low-frequency signals and color difference low-frequency signals of each level generated in the multi-resolution transform of the luminance signal and the color difference signals are preserved;

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

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

17. The image processing method of claim 10, further comprising:

applying a gradation transform to a luminance low-frequency image signal of a highest level, before applying the inverse multi-resolution transform processing.

18. The image processing method of claim 10, further comprising:

applying a gray-balance adjustment to color difference low-frequency image signals of a highest level, before applying the inverse multi-resolution transform.

19. An image processing apparatus comprising:

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

a second transforming device which transforms the luminance signal and the color difference signals separately into multi-resolution signals of level 1 to level N to produce luminance multi-resolution signals and color difference multi-resolution signals;

a third transforming device which applies 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 which applies 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 which applies the 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 which transforms the processed luminance signal and the processed color difference signals into a set of processed color image signals.

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

21. 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 a rate of change for signal values of a higher rank corresponding to at least 5% of a total number of signal values with respect to an absolute value of an input signal becomes smaller than 10%, and a rate of change for signal values of a lower rank corresponding to at least 15% of the total number becomes substantially zero.

22. 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.

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

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

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

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

a judgment device which judges a condition of a photographic object with reference to at least one of the luminance low-frequency signals, the color difference low-frequency signals, and a luminance high-frequency signal; and

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

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

a gradation transforming device which applies a gradation transform to a luminance low-frequency image signal of a highest level, before applying the inverse multi-resolution transform.

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

a gray-balance adjusting device which applies a gray-balance adjustment to color difference low-frequency image signals of a highest level before applying the inverse multi-resolution transform.

30. 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 a rate of change for signal values of a higher rank corresponding to at least 5% of a total number of signal values with respect to an absolute value of an input signal becomes smaller than 10%, and a rate of change for signal values of a lower rank corresponding to at least 15% of the total number becomes substantially zero.

28. An image processing apparatus comprising:

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

a second transforming device which transforms the luminance signal and the color difference signals separately into multi-resolution signals of level 1 to level N to produce luminance multi-resolution signals and color difference multi-resolution signals;

a third transforming device which applies 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 which applies 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 which applies the 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 which applies a sharpness enhancement processing to the processed luminance signal to produce a luminance signal of enhanced sharpness; and

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

29. The image processing apparatus of claim 28, wherein the set of color image signals representing the original image are digital image signals obtained by scanning of a dye image formed on a silver halide film.

31. image processing apparatus of claim 28, 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.

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

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

34. The image processing apparatus of claim 28, further comprising:

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

a judgment device which judges a condition of a photographic object with reference to at least one of the luminance low-frequency signals, the color difference low-frequency signals, and a luminance high-frequency signal; and

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

35. The image processing apparatus of claim 28, further comprising:

a gradation transforming device which applies a gradation transform to a luminance low-frequency image signal of a highest level, before applying the inverse multi-resolution transform.

36. The image processing apparatus of claim 28, further comprising:

a gray-balance adjusting device which applies a gray-balance adjustment to color difference low-frequency image signals of a highest level before applying the inverse multi-resolution transform.

37. A computer-readable storage medium having a program stored thereon that is executable by a computer to cause the computer to function as an image processing apparatus comprising:

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

a second transforming device which transforms the luminance signal and the color difference signals separately into multi-resolution signals of level 1 to level N to produce luminance multi-resolution signals and color difference multi-resolution signals;

a third transforming device which applies 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 which applies 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 which applies the 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 which transforms the processed luminance signal and the processed color difference signals into a set of processed color image signals.

38. The computer-readable storage medium of claim 37, wherein the set of color image signals representing the original image are digital image signals obtained by scanning of a dye image formed on a silver halide film.

39. The computer-readable storage medium of claim 37, wherein the coring processing device includes at least one processing means which performs under a non-linear coring condition such that a rate of change for signal values of a higher rank corresponding to at least 5% of a total number of signal values with respect to an absolute value of an input signal becomes smaller than 10%, and a rate of change for signal values of a lower rank corresponding to at least 15% of the total number becomes substantially zero.

40. The computer-readable storage medium 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.

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

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

43. A computer-readable storage medium of claim 37, wherein the image processing apparatus further comprises:

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

a judgment device which judges a condition of a photographic object with reference to at least one of the luminance low-frequency signals, the color difference low-frequency signals, and a luminance high-frequency signal; and

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

44. The computer-readable storage medium of claim 37, wherein the image processing apparatus further comprises a gradation transforming device which applies a gradation transform to a luminance low-frequency image signal of a highest level, before applying the inverse multi-resolution transform.

45. The computer-readable storage medium of claim 37, wherein the image processing apparatus further comprises a gray-balance adjusting device which applies a gray-balance adjustment to color difference low-frequency image signals of a highest level before applying the inverse multi-resolution transform.

46. A computer-readable storage medium having a program stored thereon that is executable by a computer to cause the computer to function as an image processing apparatus comprising:

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

a second transforming device which transforms the luminance signal and the color difference signals separately into multi-resolution signals of level 1 to level N to produce luminance multi-resolution signals and color difference multi-resolution signals;

a third transforming device which applies 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 which applies 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 which applies the 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 which applies a sharpness enhancement processing to the processed luminance signal to produce a luminance signal of enhanced sharpness; and

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

47. The computer-readable storage medium of claim 46, wherein the set of color image signals representing the original image are digital image signals obtained by scanning of a dye image formed on a silver halide film.

48. The computer-readable storage medium of claim 46, wherein the coring processing device includes at least one processing means which performs under a non-linear coring condition such that a rate of change for signal values of a higher rank corresponding to at least 5% of a total number of signal values with respect to an absolute value of an input signal becomes smaller than 10%, and a rate of change for signal values of a lower rank corresponding to at least 15% of the total number becomes substantially zero.

49. The computer-readable storage medium of claim 46, 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.

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

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

52. A computer-readable storage medium of claim 46, wherein the image processing apparatus further comprises:

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

a judgment device which judges a condition of a photographic object with reference to at least one of the luminance low-frequency signals, the color difference low-frequency signals, and a luminance high-frequency signal; and

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

53. The computer-readable storage medium of claim 46, wherein the image processing apparatus further comprises a gradation transforming device which applies a gradation transform to a luminance low-frequency image signal of a highest level, before applying the inverse multi-resolution transform.

54. The computer-readable storage medium of claim 46, wherein the image processing apparatus further comprises a gray-balance adjusting device which applies a gray-balance adjustment to color difference low-frequency image signals of a highest level before applying the inverse multi-resolution transform.