IMAGE SIGNAL CODER

摘要

PURPOSE:To attain quantization control adaptively for a local characteristic of an image in the image high efficiency coding. CONSTITUTION:An image signal received from an input terminal equipment 101 is divided into small blocks by a small block division section 102. A characteristic quantity extract section 108 extracts plural characteristic quantities for each small block and a characteristic quantity distribution state calculation section 109 calculates a distribution state of the entire image for each characteristic quantity. A weight calculation section 110 uses the distribution state of each characteristic quantity to calculate a weight coefficient for each characteristic quantity. A quantization control parameter calculation section 111 uses the calculated weight coefficient and plural characteristic quantities calculated for each small block to calculate a quantization control parameter. A quantization step calculation section 112 decides a quantization step of a quantization section 104 based on the quantization control parameter to be calculated and an occupied state of a buffer 106.