New Technique for Combined Pixel and Frequency Domain Image Sequence Coding

This paper describes a technique for producing an optimal set of linear basis function coefficients given a priori information about the image to be transmitted. In particular, when certain pixel domain data is known, the transmitted frequency coefficients can be adjusted to make use of this information. The algorithm utilizes successive projections onto two non-intersecting sets in order to determine the optimal frequency domain coefficients. This technique is best suited to fixed blocksize transform coders and builds on the techniques used in previous work (refs.2,4).