A technique for the efficient coding of the upper bands in subband coding of images

A technique is presented for efficient coding of the upper bands in subband coding (SBC) of images. The technique takes advantage of the existing correlation between the subbands and utilizes a local measure of activity in the baseband to predict the amplitude range of the pixels in the upper bands. This permits the design of quantizers better adapted to specific images, thus increasing the coding efficiency as well as enhancing the signal-to-noise ratio (SNR) and the subjective perception. The properties of the proposed technique are not fully investigated, but rather its advantages over standard techniques are demonstrated based on some simple cases