Dynamic coding with exchanging pixels

Abstract

In ordinary encoding operations, edges are disadvantageous in terms of compression because of the large amount of information involved there so that distorted and unbalanced quantization can occur as a result of encoding. Thus, in a coding apparatus according to the invention, the blocking section divided the image data into blocks. The quantity of information computing section computationally determines the quantity of information for coding the image data of each block. The pixel exchange section causes the block for which the quantity of information is computed by the quantity of information computing section and an arbitrarily selected block to exchange pixels. The controller compares the quantity of information of the block where pixels are switched by the pixel exchange section and the quantity of information of the block before the pixel exchange and determines the block to be sent to the quantizing section according to the outcome of the comparison. The quantizing section carries out an ADRC quantizing operation on the block sent from the pixel exchange section. The multiplexing section adds the ADRC quantization data to the coded data for multiplexing.