JPS55124375A - Picture element unit adaptation predictive coding system for television signal - Google Patents

Abstract

PURPOSE:To secure the effective predictive coding by indicating the distinction for the presence or absence of the differential quantization with one bit per picture element and via the control part in case the difference of the prediction value in and between the fields is over the prescribed level. CONSTITUTION:For the picture signal of the commercial TV or the TV telephone, intra-field predictive coding part 1 performs the predictive coding for the picture elements in the field by producing the predictive value via the picture element value in the same field. And inter-field predictive coding part 2 produces the predictive value via the picture element value in the preceding field in addition to that in the same field. Then in case the difference of the predictive value of in and between the fields is under the prescribed level, control part 3 gives the selection to the presence or absence of the differential equalization, and also gives the selection between the intra-field and inter-field codings. Thus the indication is given to the distinction for the presence or absence of the differential equalization with one bit par picture element as well as the distinction between the prediction inside and outside the field respectively. In such way, the effective predictive coding is ensured.