JPS6462990A - Inter-frame compression decoder - Google Patents

Abstract

PURPOSE:To improve a picture quality, by providing plural vector quantization decoding means to decode a representative vector number, in which a coefficient orthogonal transformed by means of an inter-frame encoder is decoded according to the statistical property, to the coefficient, respectively. CONSTITUTION:An encoding coefficient from the encoder is inputted to one of vector quantization decoders 1031-103n selected through a change-over switch 102 by an adaptive switching circuit 107. The vector quantization decoders 1031-103n decode the representative vector number to an orthogonal transformation coefficient, and input it through a change-over switch 105 to an orthogonal inverse transformation circuit 403. The orthogonal inverse transformation circuit 403 regenerate the decoded coefficient to a prediction error, and outputs it to an adder 404. The adder 404 adds the prediction error from the orthogonal inverse transformation circuit 403 and the predicting value from a predicting circuit 408, regenerates a digital image signal, outputs it to a D/A converter 406, and simultaneously, writes it to a frame memory 411.