Prototype image-based constraints for set-theoretic image restoration

Constraints are developed based on prototype images and used in set-theoretic image restoration. A prototype can be obtained as a result of applying a predetermined operator to the observed image. In this case, the operator and the bound, which limits the variation of the restored image from the prototype, are the two defining quantities of a prototype constraint. General guidelines for rigorously estimating the defining bound of a prototype constraint under certain simplifying conditions are discussed. Two examples of prototype constraints are provided and used in the context of projections onto convex sets. The resulting restorations show significant improvement over the Wiener restorations in reducing the restoration artifacts