EP0478217A2
Expired / Lapsed
EP
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Motion dependent video signal processing
Assignee: Sony United Kingdom Ltd
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Filing: 1991-09-18
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Granted: —
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Expires: 2011-09-18
Abstract
Abstract A motion compensated video standards converter comprises a block matcher (3) for deriving a plurality of motion vectors for each pixel of each field or frame of an output standards-converted video signal, the motion vectors representing motion between successive fields or frames of an input video signal from which the output video signal is to be derived by motion compensated interpolation, a circuit (25) for testing each said motion vector by deriving the sum of absolute luminance differences of corresponding pixels in blocks of pixels in the two fields or frames of said input video signal temporally nearest a field or frame of said output video signal, which blocks are pointed to by the motion vector under test, a circuit (26 to 28) for centre-weighting said sum of absolute luminance differences if the magnitude of said motion vector under test is less than a predetermined value, and a selector (29) for selecting from said plurality of motion vectors, the motion vector which results in the minimum said sum of absolute luminance differences.
Inventors
- 👤 Stephen Mark Keating
- 👤 Sally Janet Griffiths
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 22:12
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/01; H04N7/0135; H04N7/014
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
155 words
A method of deriving motion vectors representing motion between successive fields or frames of an input video signal from which a standards-converted output video signal is to be derived by motion compensated interpolation, the method including the steps of: deriving a plurality of motion vectors for each pixel of each field or frame of said output video signal; testing each said motion vector by deriving the sum of absolute luminance differences of corresponding pixels in blocks of pixels in the two fields or frames of said input video signal temporally nearest a field or frame of said output video signal, which blocks are pointed to by the motion vector under test; centre-weighting said sum of absolute luminance differences if the magnitude of said motion vector under test is less than a predetermined value; and selecting from said plurality of motion vectors, the motion vector which results in the minimum said sum of absolute luminance differences.
Claim 2
Dependent Claim
66 words
A method according to claim 1 wherein for each said motion vector under test a first sum of absolute luminance differences is derived for respective corresponding said blocks in said two fields or frames of said input video signal centred on the position in said field or frame pointed to by said motion vector under test, said blocks extending n pixels horizontally and m pixels vertically.
Claim 3
Dependent Claim
104 words
A method according to claim 2 wherein for each said motion vector under test of magnitude less than said predetermined value, a second sum of absolute luminance differences is derived for respective corresponding further blocks in said two fields or frames of said input video signal centred on said position in said field or frame, said further blocks extending p pixels horizontally and q pixels vertically, where p is less than n and q is less than m, and said centre-weighting includes adding said second sum of absolute luminance differences to said first sum of absolute luminance differences for said motion vector under test.
Claim 4
Dependent Claim
30 words
A method according to claim 3 wherein the sum of said second sum of absolute luminance differences and said first sum of absolute differences is normalized before said selecting step.
Claim 5
Independent Claim
46 words
A method according to any one of the preceding claims wherein said motion vectors are derived by comparing blocks in a first field or frame of said input video signal with a plurality of blocks in the following field or frame of said input video signal.
Claim 6
Dependent Claim
30 words
A method according to claim 5 wherein said block comparison is effected by comparing the sums of the luminance levels of the pixels in the respective blocks to be compared.
Claim 7
Dependent Claim
167 words
A motion compensated video standards converter comprising: means (3) for deriving a plurality of motion vectors for each pixel of each field or frame of an output standards-converted video signal, said motion vectors representing motion between successive fields or frames of an input video signal from which said output video signal is to be derived by motion compensated interpolation; means (25) for testing each said motion vector by deriving the sum of absolute luminance differences of corresponding pixels in blocks of pixels in the two fields or frames of said input video signal temporally nearest a field or frame of said output video signal, which blocks are pointed to by the motion vector under test; means (26 to 28) for centre-weighting said sum of absolute luminance differences if the magnitude of said motion vector under test is less than a predetermined value; and means (29) for selecting from said plurality of motion vectors, the motion vector which results in the minimum said sum of absolute luminance differences.
Claim 8
Dependent Claim
66 words
A converter according to claim 7 wherein for each said motion vector under test a first sum of absolute luminance differences is derived for respective corresponding said blocks in said two fields or frames of said input video signal centred on the position in said field or frame pointed to by said motion vector under test, said blocks extending n pixels horizontally and m pixels vertically.
Claim 9
Dependent Claim
104 words
A converter according to claim 8 wherein for each said motion vector under test of magnitude less than said predetermined value, a second sum of absolute luminance differences is derived for respective corresponding further blocks in said two fields or frames of said input video signal centred on said position in said field or frame, said further blocks extending p pixels horizontally and q pixels vertically, where p is less than n and q is less than m, and said centre-weighting includes adding said second sum of absolute luminance differences to said first sum of absolute luminance differences for said motion vector under test.
Claim 10
Dependent Claim
33 words
A converter according to claim 9 comprising means (28) for normalizing the sum of said second sum of absolute luminance differences and said first sum of absolute differences before said selecting is effected.
Claim 11
Dependent Claim
49 words
A converter according to any one of claims 7 to 10 wherein said means (3) for deriving said motion vectors compares blocks in a first field or frame of said input video signal with a plurality of blocks in the following field or frame of said input video signal.
Claim 12
Dependent Claim
30 words
A converter according to claim 11 wherein said block comparison is effected by comparing the sums of the luminance levels of the pixels in the respective blocks to be compared.
Claim 13
Dependent Claim
27 words
A converter according to any one of claims 7 to 12 forming a down converter and wherein said input video signal is a high definition video signal.
Claim 14
Dependent Claim
20 words
A converter according to claim 13 wherein said output video signal is a PAL 625 lines/50 fields per second signal.
Claim 15
Dependent Claim
15 words
A converter according to any one of claims 7 to 14 operable in real time.
References Cited (Backward Citations)
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