US 4,907,081 AGranted

Compression and coding device for video signals

AssigneeHitachi, Ltd.

InventorsFujio Okamura, Keizo Nishimura, Shigemitsu Higuchi, Takashi Furuhata

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Abstract

A coding device in which N digital signals (time-sequential sampled data), obtained by sampling and quantizing analog video signals, are brought together in one group (N being an integer greater than two) and coded. Among these N sampled data, at least one of them serving as a reference is coded with a number of quantization bits n, which is so great that errors due to the quantization can be neglected, and for the other sampled data the difference between the reference sampled data and each of the others is compressed and coded with a number of bits, which is smaller than n. In this way, even if a coding error is produced; effects thereof are restricted within the gorup where it is produced they are not exerted on the other groups, and thus error propagation does not occur.

Claims36

Dependent claims

A coding device, which transmits digital signals consisting of sampled data obtained by sampling and quantizing an analogue video signal with a number of quantization bits n after having compressed and coded the digital signals, comprising:

group finishing means for forming one group for every N sampled data, N being an integer greater than two;
reference sampled data setting means for setting one of the N sampled data as a reference sampled data for each of the groups formed by said group forming means;
difference calculating means for calculating the difference between at least one of the remaining sampled data in each of said groups and the reference sampled data;
compressing and coding means for coding the difference obtained by said difference calculating means with a number of bits smaller in number than the number of quantization bits n;
and
a data selector for outputting at least the reference sampled data from said reference sampled data setting means and coded differential data from said compressing and coding means as time sequential digital data.

3 more elements

group forming means for forming one group for every N sampled data, N being an integer greater than two;
reference sampled data setting means for setting one of the N sampled data as a reference sampled data for each of the groups formed by said group forming means;
predicted value forming means for forming a predicted value for at least one of the remaining sampled data in each of said groups;
difference calculating means for calculating the difference between the predicted data coming from said predicted value forming means and the at least one of the remaining sampled data;
compressing and coding means for coding the difference obtained by said difference calculating means with a number of bits smaller in number than the number of quantization bits n;
and
a data selector for outputting at least the reference sampled data from said reference sampled data setting means and coded differential data from said compressing and coding means as time sequential digital data.

4 more elements

Dependencies are inferred from the claim text.

Facts

Application: 07/184,776Filed 22 Apr 1988
Priority: JP 62-23869725 Sep 1987
Granted: 6 Mar 1990
Term ends: Not estimatedThe source records don’t support an estimate.

Classification6 codes

H04N 5/9262
Involving data reduction: using predictive coding
H04N 19/10
Methods or arrangements for coding, decoding, compressing or decompressing digital video signals: using adaptive coding
H04N 19/124
Characterised by the element, parameter or selection affected or controlled by the adaptive coding: quantisation
H04N 19/50
Methods or arrangements for coding, decoding, compressing or decompressing digital video signals: using predictive coding