Encoding method for image signal

Abstract

Abstract PURPOSE:To compress and encode an image signal with high efficiency and excellent image quality by applying the encoding in matching with the contrast of the image. CONSTITUTION:An input image is divided into plural blocks at the coder side, the contrast detector 1 analyzes the contrast of the input image for each block to classify the input image into plural types depending on the contrast. The result of classification is encoded by an image contrast coder 5 and an image encoding parameter setting device 17 seldcts the parameter and prediction coeffi cient relating to a quantization step size and coefficient selection for each type and an image coder 10 applies image encoding. The decoder side decodes the encoded result of classification to apply decoding to the coded image signal belonging to each type by using a predetermined quantization step size and prediction coefficient.

Inventors

• 👤 Shoji Mizuno

Bibliographic Details