Analyse qualitative des images par propagation de front d'ondes

This paper deals with the propagation of wavefront to analyse grey level images. We use an active contour model based on Fermat principle to adapt the algorithm that computes traveltimes to a finite difference scheme. The principles of Fermat and Huygens are taken into account in calculations as well as the phenomena of diffraction, refraction and reflection of the direct and opposite waves. The refraction index of the medium is associated to a function of the image grey levels. The wavefront differently reacts depending on whether the image is clear, dark, or presenting luminance variations.