On recovering detailed face deformation under general lighting using height from shading

Face tracking and animation are important components for many human computer interface applications. Facial motion produces transient features such as wrinkles and shading changes, which are important yet difficult issues for both analysis (tracking) and synthesis (animation). Previous approaches were mostly based on extensive training appearance examples. However it is difficult for collect samples to cover all possible lighting conditions and head poses. In this paper, we attempt to recover detailed facial geometrical changes due to facial motion under general lighting. The recovered geometry can then be used for the analysis and synthesis of the transient features and shading changes under new lighting conditions. The method is based on shading information and thus suitable for facial areas without permanent features.