Jumping snakes and parametric model for lip segmentation

Lip segmentation is an essential stage in many multimedia systems such as videoconferencing, lip reading, or low bit rate coding communication systems. In this paper, we propose an accurate and robust lip segmentation algorithm. First, the upper mouth boundary and several characteristic points are detected by using a new kind of active contour : the "jumping snake". Unlike classic snakes, it can be initialized far from the final edge and the adjustment of its parameters is easy and intuitive. In a second step, a parametric model composed of several cubic curves is fitted on the lips. This model is flexible enough to reproduce the specificities of very different lip shapes. Compared to existing models, it brings a significant accuracy and realism improvement.