Apparatus and method for processing television signals

• US 6,469,741 B2
• Filed: 05/02/2001
• Issued: 10/22/2002
• Est. Priority Date: 07/26/1993
• Status: Expired due to Fees

• Current Assignee: Pixel Instruments Corporation
• Original Assignee: Pixel Instruments Corporation
• Inventors: Cooper, J. Carl, Vojnovic, Mirko, Loveless, Howard, Wallen, David
• Primary Examiner(s): Lee, Michael
• Application Number:
  US09/848,582
• Publication Number:
  US 20010035912A1
• Time in Patent Office: 538 Days
• Field of Search: H04/N.701, H04/N 1.120, 348/513, 348/514, 348/572, 348/573, 348/714, 348/715, 348/718, 348/571, 348/441, 348/554, 348/555, 348/553, 345/605, 345/606, 345/698, 345/699
• US Class Current: 348/441
• CPC Class Codes: H04N 5/0736 using digital storage buffer techniques
• CPC Class Codes: H04N 9/475 for mutually locking different synchronisation sources

Abstract

This invention is an apparatus and method for processing television signals and in particular high quality video type signals in analog or digital form. The preferred embodiments utilizes digital storage along with oversampling, interpolation and various filtering in recursive and nonrecursive form to provide fixed or variably delayed output video signals wherein the artifacts and distortion of the video is kept to low levels.

Claims

1. An electronic apparatus for processing an input video type signal including in combination:

a) an input processing section responsive to said input video type signal to provide a processed signal having an established DC level;

b) a clock section for generating a sampling clock;

c) a sampling section operative to sample said processed signal and provide samples thereof in response to said clock section;

d) an interpolation section responsive to groups of said samples to perform interpolation thereof to provide interpolated samples having improved resolution;

e) a memory and control section to temporarily store said interpolated samples thus providing stored interpolated samples;

f) an output section responsive to said stored interpolated samples to provide an output video type signal in the same or different form as said input video type signal.

2. An apparatus as claimed in claim 1 further including a filter section responsive to said interpolated samples of d) and operable to further improve the resolution thereof.

3. An apparatus as claimed in claim 1 further including a filter section responsive to said stored interpolated samples of e) and operable to further improve the resolution thereof.

4. An apparatus as claimed in claim 1 further including a filter section responsive to said interpolated samples of d) and said stored interpolated samples of e) and operable to further improve the resolution of said interpolated samples of d).

5. An apparatus as claimed in claim 1 further including a filter section responsive to said interpolated samples of d) and said stored interpolated samples of e) and operable to further improve the resolution of said stored interpolated samples of e).

6. An apparatus as claimed in claim 1, 2, 3, 4 or 5 wherein said memory and control section of e) also provides a signal in response to the amount of time said stored interpolated samples are stored in said memory and control section.

50. The invention as claimed in claim 1, 2, 3, 4, 5, 7, 8, 9, 10, 11, 12, 13, 14, 17, 18, 19, 20, 21, 24, 25, 26, 27, 28, 29, 30, 31, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, or 49 wherein claim element e) is responsive to said input video type signal to provide said output video type signal with a fixed delay with respect to said input video type signal.

51. The invention as claimed in claim 1, 2, 3, 4, 5, 7, 8, 9, 10, 11, 12, 13, 14, 17, 18, 19, 20, 21, 24, 25, 26, 27, 28, 29, 30, 31, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, or 49 wherein claim element e) is responsive to said input video type signal to provide said output video type signal with a fixed delay with respect to said input video type signal and wherein claim element e) is responsive to operator adjustment to adjust the amount of said fixed delay.

7. An electronic apparatus for processing an input video type signal including in combination:

a) an input processing section responsive to said input video type signal to DC restore said input video type signal thereby providing a processed signal having a known DC level;

b) a clock section for generating a sampling clock;

c) a sampling section responsive to said clock section and operative to sample and digitize said processed signal to provide digital samples thereof having a first number of bits of resolution at said sampling clock rate;

d) an interpolation section responsive to groups of said digital samples to perform interpolation thereof to provide interpolated samples having a second number of bits of resolution;

e) a memory and control section to delay said interpolated samples to provide delayed interpolated samples;

f) an output section responsive to said delayed interpolated samples to provide an output video type signal in the same or different form as said input video type signal.

8. An apparatus as claimed in claim 7 further including a filter section responsive to said interpolated samples of d) and operable to improve the resolution thereof.

9. An apparatus as claimed in claim 7 further including a filter section responsive to said delayed interpolated samples of e) and operable to improve the resolution thereof.

10. An apparatus as claimed in claim 7 further including a filter section responsive to said interpolated samples of d) and said delayed interpolated samples of e) and operable to improve the resolution of said interpolated samples of d).

11. An apparatus as claimed in claim 7 further including a filter section responsive to said interpolated samples of d) and said delayed interpolated samples of e) and operable to improve the resolution of said delayed interpolated samples of e).

12. An apparatus as claimed in claim 7 wherein said first number of c) is 10 and said second number of d) is greater than 10.

13. An apparatus as claimed in claim 7 wherein in d) said interpolated samples are provided at a rate slower than said sampling clock rate of c).

14. An apparatus as claimed in claim 7 wherein said second number of d) is greater than said first number of c) and said interpolated samples of d) are provided at a rate slower than said sampling clock rate of c).

15. An apparatus as claimed in claim 7, 8, 9, 10, 11, 12, 13 or 14 wherein said memory and control section of e) also provides a signal in response to the delay time of said delayed interpolated samples.

16. An apparatus as claimed in claim 7, 8, 9, 10, 11, 12, 13 or 14 wherein said input video type signal contains an color subcarrier conforming to the NTSC or PAL standard, and the frequency of said sampling clock of b) is at least 8 times the frequency of said color subcarrier.

17. A method for processing an input video type signal including the steps:

a) in response to said input video type signal providing a processed signal having an established DC level;

b) generating a sampling clock;

c) sampling said processed signal and provide samples thereof in response to said sampling clock;

d) interpolating groups of said samples to provide interpolated samples having improved resolution;

e) temporarily storing said interpolated samples to provide stored interpolated samples;

f) providing an output video type signal in response to said stored interpolated samples with said output video signal being in the same or different form as said input video type signal.

18. A method as claimed in claim 17 further including filtering said interpolated samples of d) to improve the resolution thereof.

19. A method as claimed in claim 17 further including filtering said stored interpolated samples of e) to improve the resolution thereof.

20. A method as claimed in claim 17 further including filtering said interpolated samples of d) and said stored interpolated samples of e) to improve the resolution of said interpolated samples of d).

21. A method as claimed in claim 17 further including filtering said interpolated samples of d) and said stored interpolated samples of e) to improve the resolution of said stored interpolated samples of e).

22. A method as claimed in claim 17, 18, 19, 20 or 21 wherein said temporary storage step e) also provides a signal in response to the storage time said stored interpolated samples.

23. A method as claimed in claim 17, 18, 19, 20 or 21 wherein said input video type signal contains a color subcarrier conforming to the NTSC or PAL standard, and the frequency of said sampling clock of b) is at least 8 times the frequency of said color subcarrier.

24. A method for processing an input video type signal including the steps:

a) processing said input video type signal to DC restore said input video type signal thereby providing a processed signal having a known DC level;

b) generating a sampling clock;

c) sampling and digitizing said processed signal in response to said sampling clock to provide digital samples thereof having a first number of bits of resolution at said sampling clock rate;

d) interpolating groups of said digital samples to provide interpolated samples having a second number of bits of resolution;

e) delaying said interpolated samples to provide delayed interpolated samples;

f) providing an output video type signal in response to said delayed interpolated samples with said output video type signal being in the same or different form as said input video type signal.

25. A method as claimed in claim 24 further including filtering said interpolated samples of d) to improve the resolution thereof.

26. A method as claimed in claim 24 further including filtering said delayed interpolated samples of e) to improve the resolution thereof.

27. A method as claimed in claim 24 further including filtering said interpolated samples of d) and said delayed interpolated samples of e) to improve the resolution of said interpolated samples of d).

28. A method as claimed in claim 24 further including filtering said interpolated samples of d) and said delayed interpolated samples of e) to improve the resolution of said delayed interpolated samples of e).

29. A method as claimed in claim 24 wherein said first number of c) is 10 and said second number of d) is greater than 10.

30. A method as claimed in claim 24 wherein in d) said interpolated samples are provided at a rate slower than said sampling clock rate of c).

31. A method as claimed in claim 24 wherein said second number of d) is greater than said first number of c) and said interpolated samples of d) are provided at a rate slower than said sampling clock rate of c).

32. A method as claimed in claim 24, 25, 26, 27, 28, 29, 30 or 31 wherein said delay step e) also provides a signal in response to the delay time of said delayed interpolated samples.

33. A method as claimed in claim 24, 25, 26, 27, 28, 29, 30 or 31 wherein said input video type signal contains a color subcarrier conforming to the NTSC or PAL standard, and the frequency of said sampling clock of b) is at least 8 times the frequency of said color subcarrier.

34. A method as claimed in claim 24, 25, 26, 27, 28, 29, 30 or 31 wherein when a disruption of said input video type signal occurs, step f) provides black output video.

35. A method as claimed in claim 24, 25, 26, 27, 28, 29, 30 or 31 wherein when a disruption of said input video type signal occurs, step f) provides a known image.

36. A method as claimed in claim 24, 25, 26, 27, 28, 29, 30 or 31 wherein when a disruption of said input video type signal occurs, step f) provides a known image which known image may be an entire repetition period of stored samples from step e).

37. A method as claimed in claim 24, 25, 26, 27, 28, 29, 30 or 31 wherein when a disruption of said input video type signal occurs, step f) provides a first known image output video followed by a second known image after a time delay.

38. A method for processing and temporarily storing an analog input video type signal having scanning lines, some of which scanning lines have an active video portion, said input video signal also including a color subcarrier which may be an NTSC or PAL type, said method including for each of a plurality of said active video portions the following steps wherein M, N, X and Y are integers:

a) processing said input video type signal to DC restore said input video type signal thereby providing a processed signal having a known DC level;

b) generating a sampling clock at a frequency at least 8 times the frequency of said color subcarrier;

c) sampling and digitizing an active video portion of said processed signal in response to said sampling clock to provide X digital samples of M bits of resolution;

d) filtering each said X digital samples to provide Y filtered samples of N bits of resolution;

e) temporarily storing said Y filtered samples to provide Y delayed samples;

f) filtering said Y delayed samples to provide filtered delayed samples;

g) providing an output video type signal in response to said filtered delayed samples with said output video type signal being in the same or different form as said input video type signal.

39. A method as claimed in claim 38 wherein N is larger than M.

40. A method as claimed in claim 38 wherein N is two more than M.

41. A method as claimed in claim 38 wherein the resolution of said filtered delayed samples is equal to N.

42. A method as claimed in claim 38 wherein the resolution of said filtered delayed samples is equal to N and N is 12.

43. A method as claimed in claim 38 wherein X is greater than Y.

44. A method as claimed in claim 38 wherein X is twice Y.

45. A method as claimed in claim 38 wherein the number of said filtered delayed samples is equal to Y.

46. A method as claimed in claim 38 wherein said frequency of said sampling clock of b) is an integer multiple of the frequency of said scanning lines.

47. A method as claimed in claim 38 wherein said storing of e) includes the use of a FIFO type memory.

48. A method as claimed in claim 38 wherein said filtering of d) and said storing of e) utilize separate clocks and said storing of e) includes the use of a FIFO memory to transfer data from the clock used in said filtering of d) to the clock used in the storing of e).

49. A method as claimed in claim 38 wherein in step g) selected ones of the repetitive sync, burst and blanking are reconstructed and reinserted in the stored signals from e) as part of providing said output video signal of g).

52. An electronic apparatus for processing an input video type signal including in combination:

a) a clock section for recovering a clock;

b) a receiving section responsive to said input video type signal to provide samples thereof in response to said clock section;

c) an interpolation section responsive to groups of said samples to perform interpolation thereof to provide interpolated samples having improved resolution;

d) a memory and control section to temporarily store said interpolated samples thus providing stored interpolated samples;

e) an output section responsive to said stored interpolated samples to provide an output video type signal in the same or different form as said input video type signal.

53. An apparatus as claimed in claim 52 further including a filter section responsive to said interpolated samples of c) and operable to further improve the resolution thereof.

54. An apparatus as claimed in claim 52 further including a filter section responsive to said stored interpolated samples of d) and operable to further improve the resolution thereof.

55. An apparatus as claimed in claim 52 further including a filter section responsive to said interpolated samples of c) and said stored interpolated samples of d) and operable to further improve the resolution of said interpolated samples of c).

56. An apparatus as claimed in claim 52 further including a filter section responsive to said interpolated samples of c) and said stored interpolated samples of d) and operable to further improve the resolution of said stored interpolated samples of d).

66. The invention as claimed in claim 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63 or 64 wherein claim element d) is responsive to said input video type signal to provide said output video type signal with a fixed delay with respect to said input video type signal.

67. The invention as claimed in claim 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63 or 64 wherein claim element d) is responsive to said input video type signal to provide said output video type signal with a fixed delay with respect to said input video type signal and wherein claim element d) is responsive to operator adjustment to adjust the amount of said fixed delay.

68. The invention as claimed in claim 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63 or 64 wherein when a disruption of said input video type signal occurs, element d) provides a known image for said output video type signal.

57. A method for processing an input video type signal including the steps:

a) generating a clock in response to said input video type signal;

b) receiving said input video type signal in response to said clock to provide digital samples thereof having a first number of bits of resolution at said clock rate;

c) interpolating groups of said digital samples to provide interpolated samples having a second number of bits of resolution;

d) delaying said interpolated samples to provide delayed interpolated samples;

e) providing an output video type signal in response to said delayed interpolated samples with said output video type signal being in the same or different form as said input video type signal.

58. A method as claimed in claim 57 further including filtering said interpolated samples of c) to improve the resolution thereof.

59. A method as claimed in claim 57 further including filtering said delayed interpolated samples of d) to improve the resolution thereof.

60. A method as claimed in claim 57 further including filtering said interpolated samples of c) and said delayed interpolated samples of d) to improve the resolution of said interpolated samples of c).

61. A method as claimed in claim 57 further including filtering said interpolated samples of c) and said delayed interpolated samples of d) to improve the resolution of said delayed interpolated samples of d).

62. A method as claimed in claim 57 wherein said first number of b) is 10 and said second number of c) is greater than 10.

63. A method as claimed in claim 57 wherein in c) said interpolated samples are provided at a rate slower than said clock rate of b).

64. A method as claimed in claim 57 wherein said second number of c) is greater than said first number of b) and said interpolated samples of c) are provided at a rate slower than said clock rate of b).

65. A method as claimed in claim 57, 58, 59, 60, 61, 62, 63 or 64 wherein said memory and control section of e) also provides a signal in response to the amount of time said stored interpolated samples are stored in said memory and control section.