Un algorithme de compression d'images basé sur une représentation mixte par lignes de niveau et paquets d'ondelettes

We introduce a structured image compression scheme based on a u = v + w model, where the orignal image u is decomposed between a sketch v and a residue w. The sketch contains the main edge curves while the information carried by the residue is mostly composed by microtextures. This split of the meaningful information allows the use of a representation adapted to each structure. The edge curve geometry is detected and coded using level lines, while microtextures are compressed by means of a wavelet packet basis. In this way, one can avoid the main drawback of classical harmonic representations, the occurrence of ringing artefacts near the edges.