Improved lip fitting and tracking for model-based multimedia and coding

Finding faces, locating important facial features and model fitting are required in a range of applications including model based multimedia and coding. Accurate lip fitting is essential where a facial model is to be fitted to a head and shoulder colour image. Existing approaches to lip fitting include deformable templates and active contours. An active contour colour model using a combined balloon pressure and image gradient snake with adaptive colour thresholding for improved accuracy is described. Results from applying this technique to a large database of facial images (XM2VTS) and well known image sequences are presented. These demonstrate a high success rate for satisfactory lip fitting. Examples of facial animations using the automatically fitted faces are also included.