Automatic snakes for robust lip boundaries extraction

Active contours or snakes are widely used in object segmentation for their ability to integrate features extraction and pixel candidate linking in a single energy minimizing process. But the sensitivity to parameters values and initialization is also a widely known problem. Performance of snakes can be enhanced by better initialization close to the desired solution. We present here a ne mouth region of interest (ROI) extraction using gray level image and corresponding gradient in-formations. We link this technique with an original snake method. The Automatic Snakes use spatially varying coeecients to remain along its evolution in a mouth-like shape. Our experimentations on a large image base proove its robustness regarding speakers change of the ROI mouth extraction and automatic snakes algorithms. The main application of our algorithms is video-conferencing.