Abstract
The aim of this paper is to generalize to color images the topological gradient method for the restoration problem. First, we consider a simple extension from grey-level to color images, by considering a channel by channel method. Then, as there should be some coupling between the different channels, we propose considering a tensorial approach: the Di Zenzo gradient. We derive an asymptotic expansion of this gradient with respect to the insertion of a small crack in the image, and we propose a new algorithm based on the topological gradient for the color image restoration problem. Finally, we illustrate these two approaches with numerical results.