Estimation of the mouth features using deformable templates

Automatic estimation of mouth features is one of the important topics for face recognition and model-based coding of videophone sequences. An automatic mouth feature estimation algorithm which uses deformable templates is developed. Here, the mouth features are represented by the corner points of the mouth as well as the so called lip outline parameters. The lip outline parameters describe the opening of the mouth and the thickness of the lips. Compared to previous works, simplified cost functions are introduced. Furthermore, an algorithm for automatic determination of whether the mouth is open or closed is developed. Experimental results obtained with typical videophone sequence are given to evaluate the performance of the proposed algorithm. It is shown that in about 37% of the images the mouth features could be automatically estimated, which can be used e.g. for improving face modelling in a model-based coder.