Adaptive cosine transform coding of images in perceptual domain

An adaptive cosine transform coding scheme for color images which incorporates human visual properties into the coding scheme is described. It employs adaptive quantization to exploit the statistical nature of the coefficients and adaptive block distortion equalization to reduce the block edge structures inherent in block transform coding schemes. Results show that the subjective quality of the reconstructed images at a bit rate of 0.4 bit/pixel or a compression ratio of 60:1 is very good