Four color trilinear CCD scanning

• US 6,380,539 B1
• Filed: 01/23/1998
• Issued: 04/30/2002
• Est. Priority Date: 01/30/1997
• Status: Expired due to Fees

• Current Assignee: Eastman Kodak Company
• Original Assignee: Applied Science Fiction, Inc.
• Inventors: Edgar, Albert D.
• Primary Examiner(s): Sugarman, Scott J.
• Assistant Examiner(s): HANIG, RICHARD E
• Application Number:
  US09/012,255
• Time in Patent Office: 1,558 Days
• Field of Search: 250/339.05, 250/339.06, 250/339.11, 250/340, 250/341.1, 250/208.1, 250/226, 250/330, 282/254, 348/274
• US Class Current: 250/339.05
• CPC Class Codes: H04N 1/00795 Reading arrangements details of scanning heads H04N1/024; scanning arrangements therefor H04N1/04
• CPC Class Codes: H04N 1/4097 Removing errors due external factors, e.g. dust, scratches
• CPC Class Codes: H04N 1/486 with separate detectors, each detector being used for one specific colour component
• CPC Class Codes: H04N 5/253 Picture signal generating by scanning motion picture films or slide opaques, e.g. for telecine scanning details therefor H04N3/36 ; standard conversion therefor H04N7/0112
• CPC Class Codes: H04N 9/11 Scanning of colour motion picture films, e.g. for telecine

Abstract

A single pass scanner having a trilinear array, a source of white light, filters of the three primary colors and a separate source of infrared light is used in various methods of removing medium-based defects from a scanned film image. The method generates an infrared channel in addition to the common visible channels by covering the parallel rows of sensors in the trilinear array respectively with a red, green and blue filter to create the three color channels. Normally, each of the three color filters also passes infrared light, which is removed by filters external to the sensors. In a specific embodiment, interstitial in time between two visible light scans, the sensor is exposed to infrared light for a single scan. As the trilinear array sweeps across an image in time and spatial synchronization with the exposing lights, at least two visible channels and an infrared channel are generated.

Claims

1. A method for scanning an image on a substrate containing defects which uses a plurality of sensors arranged in groups, wherein a first group is behind a first filter material selective to a first color of light and infrared light, and a second group is behind a second filter material selective to a second different color of light and infrared light, said method comprising:

illuminating the image at a first scan time with a first light source functionally free of infrared light;

sensing light of the first color with the first group of sensors to generate a first color image, and light of the second color with the second group of sensors to generate a second color image;

illuminating the image at a second scan time with a second light source containing infrared light;

sensing infrared light with at least one of the first or second group of sensors to generate an infrared image; and

generating from the first color image, second color image, and infrared image, a corrected color image substantially free of the defects.

2. The method of claim 1 wherein the second light source substantially excludes light in the visible range.

3. The method of claim 2 wherein the first light source is a first switchable lamp, and the second light source is a second switchable lamp.

4. The method of claim 1 wherein the second light source emits light from a light emitting diode.

5. A method for scanning an image on a substrate containing defects which uses a plurality of sensors arranged in groups, wherein a first group is behind a first filter material selective to a first color of light and infrared light, and a second group is behind a second filter material selective to a second different color of light and infrared light, said method comprising:

illuminating the image at a first scan time with a first light source functionally free of infrared light;

sensing light of the first color with the first group of sensors to generate a first color image, and light of the second color with the second group of sensors to generate a second color image, wherein the first group and second group of sensors are arranged in first and second parallel rows separated by an offset;

illuminating the image at a second scan time with a second light source containing infrared light;

sensing infrared light with at least one of the first or second group of sensors to generate an infrared image; and

generating from the first color image, second color image, and infrared image, a corrected color image substantially free of the defects.

6. The method of claim 5 wherein the first scan time is one of a first sequence of scan times with light functionally free of infrared light and the second scan time is one of a second sequence of scan times in which the image is illuminated with a light source containing infrared light.

7. The method of claim 6 wherein the first sequence of scan times includes a first series of individual scan times spaced between a second series of individual scan times of the second sequence.

8. The method of claim 7 wherein the first and second series of individual scan times each comprises two individual scan times.

9. The method of claim 7 wherein the first and second series of individual scan times each comprises three individual scan times.

10. The method of claim 9 further comprising moving the parallel rows of sensors by an incremental amount in a direction perpendicular to the parallel rows between the individual scan times of the first sequence.

11. The method of claim 7 further comprising moving the parallel rows of sensors by an incremental amount in a direction perpendicular to the parallel rows between the individual scan times of the first and second sequences.

12. The method of claim 11 further comprising conducting individual scans of the second sequence based on the incremental amount so as to spatially overlay an individual scan of the first sequence.

13. The method of claim 12 wherein an individual scan of the second sequence overlays two individual scans of the first sequence.

14. The method of claim 13 further comprising

conducting a first group of individual scans selective to infrared, green, and blue light at a first pixel row site;

conducting a second group of individual scans selective to infrared, red, and blue light at a second pixel row site adjacent to the first pixel row site; and

conducting a third group of individual scans selective to infrared, red, and green light at a third pixel row site adjacent to the second pixel row site.

15. The method of claim 14 wherein a value for green is calculated for a pixel at the second pixel row site.

16. The method of claim 14 wherein a value for red is calculated for a pixel at the first pixel row site, a value for green is calculated for a pixel at the second pixel row site, and a value for blue is calculated for a pixel at the third pixel row site.

17. The method of claim 15 wherein the calculation for a value of green in the second pixel row site includes the step of averaging the value for green in adjacent pixels in the first and third pixel row sites.

18. The method of claim 17 wherein the calculation further comprises calculating the change of red value in adjacent pixels between the first and second pixel row sites.

19. The method of claim 17 wherein the calculation further comprises calculating the change of red value in adjacent pixels between the first and second pixel row sites, and the change in blue value in adjacent pixels between the third and second pixel row sites.

20. A method for scanning an image on a substrate containing defects which uses a plurality of sensors arranged in groups, wherein a first group is behind a first filter material selective to a first color of light and infrared light, and a second group is behind a second filter material selective to a second different color of light and infrared light, said method comprising:

illuminating the image at a first scan time with a first light source functionally free of infrared light;

sensing light of the first color with the first group of sensors to generate a first color image, and light of the second color with the second group of sensors to generate a second color image, wherein the first group of sensors is arranged in a two dimensional grid;

illuminating the image at a second scan time with a second light source containing infrared light;

sensing infrared light with at least one of the first or second group of sensors to generate an infrared image; and

generating from the first color image, second color image, and infrared image, a corrected color image substantially free of the defects.

21. A method for scanning an image on a substrate containing defects which uses a plurality of sensors arranged in groups, wherein a first group is behind a first filter material selective to a first color of light and infrared light, and a second group is behind a second filter material selective to a second different color of light and infrared light, said method comprising:

illuminating the image at a first scan time with a first light source functionally free of infrared light;

sensing light of the first color with the first group of sensors to generate a first color image, and light of the second color with the second group of sensors to generate a second color image, wherein the first color is red, the second color is green, and further comprising a third group of sensors behind a third filter material selective to blue light and infrared light;

illuminating the image at a second scan time with a second light source containing infrared light;

sensing infrared light with at least one of the first or second group of sensors to generate an infrared image; and

generating from the first color image, second color image, and infrared image, a corrected color image substantially free of the defects.

22. A method for scanning an image on a substrate containing defects which uses a plurality of sensors arranged in groups, wherein a first group is behind a first filter material selective to a first color of light and infrared light, and a second group is behind a second filter material selective to a second different color of light and infrared light, said method comprising:

illuminating the image at a first scan time with a first light source functionally free of infrared light;

sensing light of the first color with the first group of sensors to generate a first color image, and light of the second color with the second group of sensors to generate a second color image;

illuminating the image at a second scan time with a second light source containing infrared light, wherein the second light source also comprises visible light;

sensing infrared light with at least one of the first or second group of sensors to generate an infrared image; and

generating from the first color image, second color image, and infrared image, a corrected color image substantially free of the defects.

23. The method of claim 22 wherein the first light source is a first lamp emitting visible light, and the second light source emits a mixture of light from the first lamp and light from a switchable infrared lamp.

24. The method of claim 23 wherein the switchable infrared lamp is a light emitting diode.

25. The method of claim 23 wherein the light from the switchable infrared lamp is calculated as a difference between the second light source and the first light source.

26. An apparatus for scanning an image on a substrate containing defects comprising:

a plurality of sensors arranged in groups, wherein a first group is behind a first filter material selective to a first color of light and infrared light, and a second group is behind a second filter material selective to a second different color of light and infrared light;

means for illuminating the image at a first scan time with a first light source functionally free of infrared light;

means for sensing light of the first color with the first group of sensors to generate a first color image, and light of the second color with the second group of sensors to generate a second color image;

means for illuminating the image at a second scan time with a second light source containing infrared light;

means for sensing infrared light with at least one of the first or second group of sensors to generate an infrared image; and

means for generating from the first color image, second color image, and infrared image, a corrected color image substantially free of the defects.

27. The apparatus of claim 26 wherein the second light source substantially excludes light in the visible range.

28. The apparatus of claim 27 wherein the first light source is a first switchable lamp, and the second light source is a second switchable lamp.

29. The apparatus of claim 26 wherein the second light source emits light from a light emitting diode.

30. An apparatus for scanning an image on a substrate containing defects comprising:

a plurality of sensors arranged in groups, wherein a first group is behind a first filter material selective to a first color of light and infrared light, and a second group is behind a second filter material selective to a second different color of light and infrared light, wherein the first group and second group of sensors are arranged in first and second parallel rows separated by an offset;

means for illuminating the image at a first scan time with a first light source functionally free of infrared light;

means for sensing light of the first color with the first group of sensors to generate a first color image, and light of the second color with the second group of sensors to generate a second color image;

means for illuminating the image at a second scan time with a second light source containing infrared light;

means for sensing infrared light with at least one of the first or second group of sensors to generate an infrared image; and

means for generating from the first color image, second color image, and infrared image, a corrected color image substantially free of the defects.

31. The apparatus of claim 30 wherein the first scan time is one of a first sequence of scan times with light functionally free of infrared light, and the second scan time is one of a second sequence of scan times in which the image is illuminated with a light source containing infrared light.

32. The apparatus of claim 31 wherein the first sequence of scan times includes a first series of individual scan times spaced between a second series of individual scan times of the second sequence.

33. The apparatus of claim 32 wherein the first and second series of individual scan times each comprises two individual scan times.

34. The apparatus of claim 32 wherein the first and second series of individual scan times each comprises three individual scan times.

35. The apparatus of claim 31 wherein the parallel rows of sensors are moved by an incremental amount in a direction perpendicular to the parallel rows between the individual scan times of the first sequence.

36. The apparatus of claim 31 wherein the parallel rows of sensors are moved by an incremental amount in a direction perpendicular to the parallel rows between the individual scan times of the first and second sequences.

37. The apparatus of claim 36 wherein the incremental amount enables, in conjunction with the offset between parallel rows of sensors, individual scans of the second sequence to spatially overlay individual scans of the first sequence.

38. The apparatus of claim 37 wherein the incremental amount enables an individual scan of the second sequence to overlay two individual scans of the first sequence.

39. The apparatus of claim 38 wherein sites of overlay are pixel row sites, and wherein a first pixel row site includes individual scans selective to infrared, green, and blue light;

a second pixel row site adjacent to the first pixel row site includes individual scans selective to infrared, red, and blue light; and

a third pixel row site adjacent to the second pixel row site includes individual scans selective to infrared, red, and green light.

40. The apparatus of claim 39 further comprising means for calculating a value for green for a pixel at the second pixel row site.

41. The apparatus of claim 39 further comprising means for calculating a value for red for a pixel at the first pixel row site, a value for green for a pixel at the second pixel row site, and a value for blue for a pixel at the third pixel row site.

42. The apparatus of claim 40 wherein the means for calculating a value of green in the second pixel row site further comprises means for averaging the value for green in adjacent pixels in the first and third pixel row sites.

43. The apparatus of claim 42 wherein the means for calculating further comprises means for calculating the change of red value in adjacent pixels between the first and second pixel row sites.

44. The apparatus of claim 42 wherein the means for calculating further comprises means for calculating the change of red value in adjacent pixels between the first and second pixel row sites, and the change in blue value in adjacent pixels between the third and second pixel row sites.

45. An apparatus for scanning an image on a substrate containing defects comprising:

a plurality of sensors arranged in groups, wherein a first group is behind a first filter material selective to a first color of light and infrared light, and a second group is behind a second filter material selective to a second different color of light and infrared light, wherein the first color is red, the second color is green, and further comprising a third group of sensors behind a third filter material selective to blue light and infrared light;

means for illuminating the image at a first scan time with a first light source functionally free of infrared light;

means for sensing light of the first color with the first group of sensors to generate a first color image, and light of the second color with the second group of sensors to generate a second color image;

means for illuminating the image at a second scan time with a second light source containing infrared light;

means for sensing infrared light with at least one of the first or second group of sensors to generate an infrared image; and

means for generating from the first color image, second color image, and infrared image, a corrected color image substantially free of the defects.

46. An apparatus for scanning an image on a substrate containing defects comprising:

a plurality of sensors arranged in groups, wherein a first group is behind a first filter material selective to a first color of light and infrared light, and a second group is behind a second filter material selective to a second different color of light and infrared light;

means for illuminating the image at a first scan time with a first light source functionally free of infrared light;

means for sensing light of the first color with the first group of sensors to generate a first color image, and light of the second color with the second group of sensors to generate a second color image;

means for illuminating the image at a second scan time with a second light source containing infrared light, wherein the second light source emits visible light;

means for sensing infrared light with at least one of the first or second group of sensors to generate an infrared image; and

means for generating from the first color image, second color image, and infrared image, a corrected color image substantially free of the defects.

47. The apparatus of claim 46 wherein the first light source is a first lamp emitting visible light, and the second light source emits a mixture of light from the first lamp and light from a switchable infrared lamp.

48. The apparatus of claim 47 wherein the switchable infrared lamp is a light emitting diode.

49. The apparatus of claim 48 wherein the light from the switchable infrared lamp is calculated as a difference between the second light source and the first light source.

50. An apparatus for scanning an image on a substrate containing defects comprising:

a plurality of sensors arranged in groups, wherein a first group is behind a first filter material selective to a first color of light and infrared light, and a second group is behind a second filter material selective to a second different color of light and infrared light;

a first light source configured to illuminate an image at a first scan time with light functionally free of infrared light, wherein the first group of sensors sense the first color of the light to generate a first color image and the second group of sensors sense the second color of the light to generate a second color image;

a second light source configured to illuminate the image at a second scan time with infrared light, wherein at least one of the first or second group of sensors sense the infrared light to generate an infrared image; and

at least one computing device configured to generate a corrected color image from the first color image, the second color image, and the infrared image.