Inner and outer lip contour tracking using cubic curve parametric models

Abstract

International audienceThe first step in lipreading applications is mouth contour extraction to provide the link between lip shape and the oral message. In our approach, the lip contours are detected in the first image with the two algorithms developed in [1] and [2] for static images. On subsequent images of the sequence, several key points (mouth corners and inner and outer middle contour points) are tracked with the Lucas-Kanade method to define an initial parametric lip model of the mouth. According to a combined luminance and chrominance gradient, the model is optimized and precisely locked onto the lip contours. The algorithm performances are evaluated with regard to a lipreading application