Method and apparatus for video line multiplication with enhanced sharpness

• US 6,266,092 B1
• Filed: 05/12/1998
• Issued: 07/24/2001
• Est. Priority Date: 05/12/1998
• Status: Expired due to Fees

• Current Assignee: Tamiras Per Pte Ltd LLC (Intellectual Ventures LLC)
• Original Assignee: Genesis Microchip Inc. (STMicroelectronics NV)
• Inventors: Wang, Zhongde, Greggain, Lance, Selby, Steve
• Primary Examiner(s): Eisenzopf, Reinhard J.
• Assistant Examiner(s): DESIR, JEAN WICEL
• Application Number:
  US09/075,836
• Time in Patent Office: 1,169 Days
• Field of Search: H04/N.701, H04/N.521, 348/448, 348/441, 348/445, 348/447, 348/458, 348/459, 348/625, 348/252, 348/910, 348/911, 382/266, 382/269, 382/275, 382/300, 358/532, 358/447
• US Class Current: 348/448
• CPC Class Codes: H04N 5/208 for compensating for attenuation of high frequency components, e.g. crispening, aperture distortion correction
• CPC Class Codes: H04N 7/012 Conversion between an interlaced and a progressive signal for graphics images G09G2310/0229
• CPC Class Codes: H04N 7/0135 involving interpolation processes interpolation-based image scaling G06T3/4007; interpolation for video coding H04N19/587, H04N19/59
• CPC Class Codes: Y10S 348/91 Flicker reduction
• CPC Class Codes: Y10S 348/911 Line doubler adapted for reproducing program originally from film, e.g. 24 frame per second

Abstract

A method of de-interlacing used to convert an interlaced video signal to a progressively scanned format utilizing vertical temporal filtering to generate the missing lines, utilizing appropriate filter coefficients to give a desired vertical frequency response, and filter utilizing coefficients such that the total combined contribution from all fields is unity while the total contribution from each individual field is chosen so as to boost higher temporal frequencies which has the perceived effect of increasing the sharpness of moving edges. Furthermore, in order to avoid certain unwanted artifacts, the lines of the current field are modified using a vertical temporal filter with similar temporal boosting properties to that which was used to generate the missing lines.

Claims

1. Apparatus for generating an interpolated line of video, comprising first means for multiplying data from video lines on opposite sides of said interpolated line in a video field by first predetermined coefficients and in response generating a first plurality of product signals, second means for multiplying data from video lines in one or more adjacent video fields by further predetermined coefficients and in response generating a plurality of further product signals, and means for summing said first and further product signals to generate said interpolated line of video which is a weighted average of said data in said video lines of said video field and said one or more adjacent video fields, and wherein said coefficients are chosen such that a first contribution from said video field is greater than a first predetermined value, a further contribution from said one or more adjacent video fields is negative and the total contribution from all video fields sums to said first predetermined value.

2. The apparatus of claim 1, further including means for modifying a video line of said video field by multiplying data from each said line and lines on opposite sides thereof within said video field by first additional coefficients and in response generating a first plurality of additional product signals and multiplying data from video lines of said one or more adjacent video fields by further additional coefficients and in response generating a further plurality of additional product signals and summing said first and further additional product signals so as to generate a modified line of video which is a weighted average of said data in said video lines of said video field and said one or more adjacent video fields, wherein said additional coefficients are chosen such that the contribution from said video field is equal to said first contribution and the contribution from said one or more additional video fields is equal to said further contribution.

3. The apparatus of claim 2, wherein said first means comprises a first plurality of multipliers and intermediate line storage means for multiplying data from video lines on opposite sides of said interpolated line in said video field by said first predetermined coefficients, said second means comprises a second plurality of multipliers and intermediate line storage means for multiplying data from said video lines in said one or more adjacent video fields by said further predetermined coefficients, and said means for summing comprises a multiple input summer connected to respective outputs of said multipliers.

4. The apparatus of claim 3, wherein said means for modifying further comprises a first plurality of multiplexers associated with said video field having first inputs for receiving said first predetermined coefficients, second inputs for receiving said first additional coefficients and outputs connected to respective ones of said first plurality of multipliers, and a second plurality of multiplexers associated with said one or more adjacent video fields having first inputs for receiving said further predetermined coefficients, second inputs for receiving said further additional coefficients, and outputs connected to respective ones of said second plurality of multipliers.

5. The apparatus of claim 4, further comprising a random access memory for storing said data in said video lines of said video field and said one or more adjacent video fields and a memory controller for writing said data to said random access memory and reading said data from said random access memory for application to at least one of said first and second pluralities of multipliers and intermediate line storage means.

6. The apparatus of claim 3, wherein said means for modifying further comprises a plurality of coefficient storage banks connected to respective ones of said multipliers for storing and applying said coefficients to said multipliers.

7. The apparatus of claim 6, wherein each of said coefficient storage banks stores a plurality of selectable sets of said coefficients for application to said multipliers for enabling line interpolation in spatial regions between said video lines.

8. The apparatus of claim 7, further comprising a random access memory for storing said data in said video lines of said video field and said one or more adjacent video fields and a memory controller for writing said data to said random access memory and reading said data from said random access memory for application to at least one of said first and second pluralities of multipliers and intermediate line storage means.

9. The apparatus of claim 1, wherein said predetermined value is one.

10. A video line generating apparatus, comprising:

a first multiplier generating first product signals by multiplying data from first video lines in a first video field by predetermined first coefficients summing to a first value greater than a predetermined value;

a second multiplier generating second product signals by multiplying data from video lines in one or more adjacent video fields by predetermined second coefficients summing to a negative second value, the first and second coefficients together summing to the predetermined value; and

a first adder generating an interpolated video line by summing the first and second product signals.

11. The apparatus of claim 10, further comprising a video line modifier modifying a specific video line in the first video field, said video line modifier comprising:

a third multiplier generating a first plurality of additional product signals by multiplying data from each of a specified plurality of video lines by first additional coefficients summing to the first value, the specified plurality of video lines comprising the specific video line and video lines on opposite sides thereof in the first video field;

a fourth multiplier generating a further plurality of additional product signals by multiplying data from video lines in the one or more adjacent video fields by further additional coefficients summing to the second value; and

a second adder generating a modified video line, as a weighted average of the data in the specified plurality of video lines and the video lines of the one or more adjacent video fields, by summing the first additional and further additional product signals.

12. The apparatus of claim 11, wherein:

said first multiplier comprises a first plurality of multiplier stages and one or more first intermediate line storages;

said second multiplier comprises a second plurality of multiplier stages and one or more second intermediate line storages; and

said first adder comprises a multiple input summer having inputs connected to respective outputs of said first and second multipliers.

13. The apparatus of claim 12, wherein said video line modifier further comprises:

a first plurality of multiplexers associated with the first video field and having first inputs for receiving the first predetermined coefficients, second inputs for receiving the first additional coefficients, and outputs connected to respective ones of the first plurality of multiplier stages; and

a second plurality of multiplexers associated with the one or more adjacent video fields and having first inputs for receiving the further predetermined coefficients, second inputs for receiving the further additional coefficients, and outputs connected to respective ones of the second plurality of multiplier stages.

14. The apparatus of claim 13, further comprising:

a memory for storing the data of the specified plurality of video lines and the video lines of the one or more adjacent video fields; and

a memory controller for writing the data to said memory and reading the data from said memory for application to at least one of the first and second pluralities of multiplier stages and the first and second one or more intermediate line storages.

15. The apparatus of claim 12, wherein said video line modifier further comprises a plurality of coefficient storage banks connected to respective ones of said multipliers for storing and applying the respective coefficients thereto.

16. The apparatus of claim 15, wherein each of the coefficient storage banks stores a plurality of selectable sets of the respective coefficients for application to said multipliers, thereby enabling line interpolation in spatial regions between ones of the specified plurality of video lines.

17. The apparatus of claim 16, further comprising:

a memory for storing the data of the specified plurality of video lines and the video lines of the one or more adjacent video fields; and

a memory controller for writing the data to said memory and reading the data from said memory for application to at least one of the first and second pluralities of multiplier stages and the first and second one or more intermediate line storages.

18. The apparatus of claim 10, wherein the predetermined value is 1.

19. A video line generation method, comprising:

generating first product signals by multiplying data from first video lines in a first video field by predetermined first coefficients summing to a first value greater than a predetermined value;

generating second product signals by multiplying data from video lines in one or more adjacent video fields by predetermined second coefficients summing to a negative second value, the first and second coefficients together summing to the predetermined value; and

generating an interpolated video line by summing the first and second product signals.

20. The method according to claim 19, further comprising modifying a specific video line in the first video field by a modifying procedure comprising:

generating a first plurality of additional product signals by multiplying data from each of a specified plurality of video lines by first additional coefficients summing to the first value, the specified plurality of video lines comprising the specific video line and video lines on opposite sides thereof in the first video field;

generating a further plurality of additional product signals by multiplying data from video lines in the one or more adjacent video fields by further additional coefficients summing to the second value; and

generating a modified video line, as a weighted average of the data in the specified plurality of video lines and the video lines of the one or more adjacent video fields, by summing the first additional and further additional product signals.

21. The method of claim 20, wherein:

the first product signal generating operation comprises a first plurality of stage multiplications and one or more first intermediate line stores for multiplying the data from the first video lines by the first predetermined coefficients;

the second product signal generating operation comprises a second plurality of stage multiplications and one or more second intermediate line stores for multiplying the data of the one or more adjacent video fields by the further predetermined coefficients; and

the interpolated video line generating operation comprises summing respective results of the first and second product signal generating operations.

22. The method of claim 21, wherein the video line modifying procedure further comprises:

multiplexing the first predetermined coefficients with respective ones of the first additional coefficients for input to respective ones of the first plurality of stage multiplications;

multiplexing the further predetermined coefficients with respective ones of the further predetermined coefficients for input to respective ones of the second plurality of stage multiplications.

23. The method of claim 22, further comprising:

writing the data of the specified plurality of video lines and the video lines of the one or more adjacent video fields in a memory; and

reading the data from the memory for application to at least one of the first and second pluralities of stage multiplications and the first and second one or more intermediate line stores.

24. The method of claim 21, wherein the video line modifying procedure further comprises:

storing respective ones of the coefficients in a plurality of coefficient storage banks; and

reading the coefficients from the coefficient storage banks for application in the first and second product signal generating operations.

25. The method of claim 24, wherein the coefficient storing operation further comprises storing a plurality of selectable sets of the respective coefficients for application in the first and second product signal generating operations, thereby enabling line interpolation in spatial regions between ones of the specified plurality of video lines.

26. The method of claim 25, further comprising:

writing the data of the specified plurality of video lines and the video lines of the one or more adjacent video fields in a memory; and

reading the data from the memory for application to at least one of the first and second pluralities of stage multiplications and the first and second one or more intermediate line stores.

27. The method of claim 19, wherein the predetermined value is 1.

28. A computer-readable medium encoded with a program for video line generation, said program comprising procedures for:

generating first product signals by multiplying data from first video lines in a first video field by predetermined first coefficients summing to a first value greater than a predetermined value;

generating second product signals by multiplying data from video lines in one or more adjacent video fields by predetermined second coefficients summing to a negative second value, the first and second coefficients together summing to the predetermined value; and

generating an interpolated video line by summing the first and second product signals.

29. The computer-readable medium according to claim 28, wherein said program further comprises a procedure for modifying a specific video line in the first video field, the video line modifying procedure comprising sub-procedures for:

generating a first plurality of additional product signals by multiplying data from each of a specified plurality of video lines by first additional coefficients summing to the first value, the specified plurality of video lines comprising the specific video line and video lines on opposite sides thereof in the first video field;

generating a further plurality of additional product signals by multiplying data from video lines in the one or more adjacent video fields by further additional coefficients summing to the second value; and

generating a modified video line, as a weighted average of the data in the specified plurality of video lines and the video lines of the one or more adjacent video fields, by summing the first additional and further additional product signals.

30. The computer-readable medium of claim 29, wherein:

the first product signal generating procedure comprises instructions for a first plurality of stage multiplications and one or more first intermediate line stores for multiplying the data from the first video lines by the first predetermined coefficients;

the second product signal generating procedure comprises instructions for a second plurality of stage multiplications and one or more second intermediate line stores for multiplying the data of the one or more adjacent video fields by the further predetermined coefficients; and

the interpolated video line generating procedure comprises instructions for summing respective results of the first and second product signal generating operations.

31. The computer-readable medium of claim 30, wherein the video line modifying procedure further comprises sub-procedures for:

multiplexing the first predetermined coefficients with respective ones of the first additional coefficients for input to respective ones of the first plurality of stage multiplications;

multiplexing the further predetermined coefficients with respective ones of the further predetermined coefficients for input to respective ones of the second plurality of stage multiplications.

32. The computer-readable medium of claim 31, wherein said program further comprises procedures for:

writing the data of the specified plurality of video lines and the video lines of the one or more adjacent video fields in a memory; and

reading the data from the memory for application to at least one of the first and second pluralities of stage multiplications and the first and second one or more intermediate line stores.

33. The computer-readable medium of claim 30, wherein the video line modifying procedure further comprises sub-procedures for:

storing respective ones of the coefficients in a plurality of coefficient storage banks; and

reading the coefficients from the coefficient storage banks for application in the first and second product signal generating procedures.

34. The computer-readable medium of claim 33, wherein the coefficient storing sub-procedure further comprises instructions for storing a plurality of selectable sets of the respective coefficients for application in the first and second product signal generating operations, thereby enabling line interpolation in spatial regions between ones of the specified plurality of video lines.

35. The computer-readable medium of claim 34, wherein said program further comprises procedures for:

writing the data of the specified plurality of video lines and the video lines of the one or more adjacent video fields in a memory; and

reading the data from the memory for application to at least one of the first and second pluralities of stage multiplications and the first and second one or more intermediate line stores.

36. The computer-readable medium of claim 28, wherein the predetermined value is 1.

37. A progressively scanned video signal generator, comprising:

means for generating a weighted average of first data from first video lines in a first video field and second data from second video lines in one or more adjacent video fields using first coefficients corresponding to the first data and second coefficients corresponding to the second data, the first video field corresponding to a selected phase of an interlaced video frame, a sum of the first coefficients being greater than a predetermined value, a sum of the second coefficients being negative, and a sum of the first and second coefficients being equal to the predetermined value; and

means for generating a non-interlaced video frame corresponding to the interlaced video frame and including an interpolated video line generated from the weighted average.