Digital video signal compression

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United States of America Patent

PATENT NO 5021880
SERIAL NO

07538627

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ATTORNEY / AGENT: (SPONSORED)

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Abstract

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Digital samples of an HDTV video signal are compressed by determining groups each of three successive samples in the video signal lines, the groups in adjacent lines being offset from one another, and transmitting only a first sample in each group. Each of the second and third samples in each group is compared with magnitudes averaged from three adjacent, transmitted, first samples, one in each of the previous, same, and following video signal lines, to determine a closest match. A 2-bit code representing this closest match is transmitted for each of these second and third samples in each group. The groups, and hence the first samples, are offset from one another in adjacent video signal lines, and the sampling frequency is desirably an odd multiple of half the video signal line frequency to offset the sampled pixels in adjacent video signal lines. The invention provides a high compression ratio, which can be further increased by DPCM encoding of the successive first samples.

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Patent Owner(s)

Patent OwnerAddress
NORTEL NETWORKS LIMITEDST LAURENT QUEBEC H4S 2A9

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Inventor(s)

Inventor Name Address # of filed Patents Total Citations
Graves, Alan F Kanata, CA 52 1806
Greenfield, Raymond L London, CA 4 124
Hagglund, Barry B Nepean, CA 4 208

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