A study of convex coders with an application to image coding

The concept of convex coding systems is presented together with an application to image coding. A convex coder gives the exact description of a convex set or a group of convex sets in which the input signal is located. The reconstruction is left to the decoder whose role is to pick an estimate in the intersection of these sets. Alternating projections can be used to obtain such estimates which geometrically lie in the intersection of the sets. Convex coding enables us to supplement a criterion of "pleasingness" to the current MSE-oriented criterion. This may be useful for very high compression ratio. An example of convex coding which utilizes the conventional DCT coder as one set is demonstrated and the result shows that the blocking artifacts are efficiently removed.<>