CODER, CODING METHOD, DECODER, DECODING METHOD, TRANSMITTER-RECEIVER, AND TRANSMISSION-RECEPTION METHOD

摘要

PROBLEM TO BE SOLVED: To apply compression expansion to an image through a simple processing and to display an image at halfway progress in expansion processing. SOLUTION: An original image given to an encoder 1 is subject to 1/2 band limit filter processing in horizontaland vertical directions, and pixels are extracted at a ratio of 1/4. The extracted pixels are grouped into blocks each comprising 3×3 pixels and adaptive dynamic range coding (ADRC) processing is applied to each block, and the result is converted into an analog signal by a modem 2, and the signal is sent to a receiver side via a public line. The receiver side uses a modem 3 for receiving data to be sent, converts the data into digital data and gives the data to a decoder 4. The decoder 4 decodes the image whose information quantity is interleaved to 1/4 through the adaptive coding processing, and the result is outputted to a switch 5 as a preview image. Furthermore, the preview image is up-converted by an up-converter and the result is outputted to the switch 5 as an up-convert image with the same resolution as that of an original image. The switch 5 selects any one of the images, and the selected signal is feed to a CRT monitor 6, on which the image is displayed.