Facial pose using shape-from-shading

This paper reports the application of a novel shape-from-shading technique to estimating facial pose. The shape-from-shading algorithm uses a new ge-ometric technique for solving the image irradiance equation together with curvature consistency constraints. Orientation histograms extracted from the the needle maps delivered by the new shape-from-shading algorithm are used to estimate facial pose. We present a simple model of how the histogram bin-contents transform under rotation of the head. The parameters of this model are the head pose angles. We estimate pose by searching for the rotation angles which maximise the correlation between transformed histograms. A sensitivity analysis reveals that the methods can deliver pose estimates that are accurate to within a few degrees.