PRAEDIKTIVER STANDBILDCODIERER

摘要

The predictive still-frame encoder described contains a quantiser (Q), the characteristic of which can be changed. From an output buffer (BMUX), the coded image data are read out and transmitted at constant bit rate. A subtracting circuit (SR) and a frame buffer (BS) are used for obtaining prediction values. In order to be able to transmit the still frames coming from a video camera without significant loss in quality, a first frame buffer (V1) is provided in which the data of all picture elements of the still frame to be transmitted are stored. A selection circuit (AS) adjusts the characteristic in accordance with which the quantiser (Q) quantises. If the data stored in the first frame buffer (V1) are transmitted several times, the selection circuit (AS) selects for each encoding and transmission a characteristic which corresponds to a finer degree of quantisation than the characteristic which was used in the preceding encoding and transmission. <IMAGE>