EP0468628A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Motion dependent video signal processing
Assignee: Sony United Kingdom Ltd
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Filing: 1991-06-10
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Granted: —
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Expires: 2011-06-10
Abstract
Abstract In, for example, a motion compensated video standards converter (Figure 1) wherein blocks in a first field or frame of a video signal are each compared with a plurality of blocks in the following field or frame of the video signal for deriving motion vectors representing the motion of the content of respective blocks between the first field or frame and the following field or frame, and wherein a correlation surface is generated for each block in the first field or frame, the correlation surface representing the difference between the content of the first block in the first field or frame and the content of each block in the following field or frame with which it has been compared; the minimum difference represented by the correlation surface and differing from the next smallest difference represented by the correlation surface by more than a predetermined threshold value is found to derive a motion vector, the number of motion vectors so derived is averaged (62) over a predetermined number of fields or frames, and the threshold value is varied (67, 68, 69) in dependence on the average.
Inventors
- 👤 Nicholas Ian Saunders
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 23:01
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/01; H04N7/0135; H04N7/014; H04N7/0125; H04N7/015
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
207 words
A motion compensated video standards converter comprising: means (3) for comparing blocks in a first field or frame of a video signal with a plurality of blocks in the following field or frame of the video signal for deriving motion vectors representing the motion of the content of respective said blocks between said first field or frame and said following field or frame, by generating a respective correlation surface for blocks in said first field or frame, said correlation surface representing the difference between the content of the said block in said first field or frame and the content of each block in said following field or frame with which it has been compared; means (4) to determine from said correlation surface the motion vector corresponding to the minimum value of said difference, by determining the minimum difference represented by said correlation surface which differs from the next smallest difference represented by said correlation surface by more than a predetermined threshold value; means (62) to average the number of said motion vectors so determined over a predetermined number of fields or frames; means (67, 68, 69) to vary said threshold value in dependence on said average; and an interpolator (8) controlled in dependence on said motion vectors.
Claim 2
Dependent Claim
207 words
A motion compensated video standards converter comprising: means (3) for comparing blocks in a first field or frame of a video signal with a plurality of blocks in the following field or frame of the video signal for deriving motion vectors representing the motion of the content of respective said blocks between said first field or frame and said following field or frame, by generating a respective correlation surface for blocks in said first field or frame, said correlation surface representing the difference between the content of the said block in said first field or frame and the content of each block in said following field or frame with which it has been compared; means (4) to determine from said correlation surface the motion vector corresponding to the minimum value of said difference, by determining the minimum difference represented by said correlation surface which differs from the next smallest difference represented by said correlation surface by more than a predetermined threshold value; means (62) to average the number of said motion vectors so determined over a predetermined number of fields or frames; means (67, 68, 69) to vary said threshold value in dependence on said average; and an interpolator (8) controlled in dependence on said motion vectors.
Claim 3
Dependent Claim
18 words
A converter according to claim 1 comprising means (62) to vary said predetermined number of fields or frames.
Claim 4
Dependent Claim
31 words
A converter according to claim 1 or claim 2 comprising means (63, 64) to cause hysteresis in said varying of said threshold value, and means (63, 64) to vary said hysteresis.
Claim 5
Dependent Claim
36 words
A converter according to claim 1, claim 2 or claim 3 comprising means (67, 68, 69) to limit the maximum rate of change of said threshold value, and means (67, 68, 69) to vary said limit.
Claim 6
Dependent Claim
33 words
A converter according to any one of the preceding claims wherein said comparison is effected by comparing the sums of the luminance levels of the pixels in the respective blocks to be compared.
Claim 7
Independent Claim
199 words
A method of deriving motion vectors representing motion between successive fields or frames of a video signal, the method including the steps of: comparing blocks in a first field or frame of the video signal with a plurality of blocks in the following field or frame of the video signal for deriving motion vectors representing the motion of the content of respective said blocks between said first field or frame and said following field or frame; generating a correlation surface for each said block in said first field or frame, said correlation surface representing the difference between the content of the said block in said first field or frame and the content of each block in said following field or frame with which it has been compared; determining from said correlation surface the motion vector corresponding to the minimum value of said difference, by determining the minimum difference represented by said correlation surface which differs from the next smallest difference represented by said correlation surface by more than a predetermined threshold value; averaging the number of said motion vectors so determined over a predetermined plurality of fields or frames; and varying said threshold value in dependence on said average.
Claim 8
Independent Claim
199 words
A method of deriving motion vectors representing motion between successive fields or frames of a video signal, the method including the steps of: comparing blocks in a first field or frame of the video signal with a plurality of blocks in the following field or frame of the video signal for deriving motion vectors representing the motion of the content of respective said blocks between said first field or frame and said following field or frame; generating a correlation surface for each said block in said first field or frame, said correlation surface representing the difference between the content of the said block in said first field or frame and the content of each block in said following field or frame with which it has been compared; determining from said correlation surface the motion vector corresponding to the minimum value of said difference, by determining the minimum difference represented by said correlation surface which differs from the next smallest difference represented by said correlation surface by more than a predetermined threshold value; averaging the number of said motion vectors so determined over a predetermined plurality of fields or frames; and varying said threshold value in dependence on said average.
Claim 9
Dependent Claim
16 words
A method according to claim 6 wherein said predetermined plurality of fields or frames is varied.
Claim 10
Dependent Claim
22 words
A method according to claim 6 or claim 7 wherein said threshold value is varied with hysteresis, and said hysteresis is varied.
Claim 11
Dependent Claim
28 words
A method according to claim 6, claim 7 or claim 8 wherein the maximum rate of change of said threshold value is limited, and said limit is varied.
Claim 12
Independent Claim
34 words
A method according to any one of claims 6 to 9 wherein said comparison is effected by comparing the sums of the luminance levels of the pixels in the respective blocks to be compared.
References Cited (Backward Citations)
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