Adaptive type compression method for compressing a color image by imparting predetermined variable-length codes to combinations of quantized values based upon quantized prediction error components

摘要

An adaptive type compression method for a color image in which each sequence of picture elements obtained by combination of sum-difference transformation with DPCM is compressed by being multiplied by an adaptive zonal filter. The sum-difference transformation is used to simplify transformation of the image into a spatial frequency zone. The zone filter characteristic is adaptively selected according to a predetermined transmission bit rate (compression rate). Further, this zonal filter characteristic is set so as to correspond with luminance and color difference signals. According to this method, image information to be recorded can be arbitrarily selected and distortion of the image at compressing and reproducing can be eliminated.