In this chapter, we shall review some of the important and recent applications of local regularity and multifractal analysis to signal/image processing. Obviously, we will not aim at a complete coverage of the field, which would require a book of its own:(multi) fractal processing of signals and images is indeed now present in numerous applications. Rather, we will concentrate on a few topics, and try to explain in a very concrete manner how tools developed for the study of irregular functions may be applied to solve typical signal processing problems.