Method and apparatus for tracking features

A system for facial modelling, comprising:

• input means for receiving stereo image data comprising a set of corresponding first and second stereo-rectified image frames indicative of a target;
• annotating means for determining a location of an image feature in the first and second stereo-rectified image frames, wherein the determined locations in the first and second stereo-rectified image frames are positionally constrained according to an epipolar constraint;
• and
• training means for training a shape variation model according to the determined image feature locations.

A system for determining facial features, comprising:

• input means for receiving stereo image data comprising a set of corresponding first and second stereo-rectified image frames indicative of a target;
• a processor for using a stored shape variation model to determine parameters associated with at least one image feature identified in the stereo image data;
• and
• output means for outputting the parameters associated with the at least one image feature.