Psoriasis segmentation through chromatic regions and Geometric Active Contours.

We present a novel approach to the segmentation of psoriasis lesions in "full body" digital photographs potentially involving dozens or even hundreds of separate lesions. Our algorithm first isolates a set of zones that certainly correspond to lesional plaques based on chromatic information, and then expands these zones to achieve an accurate segmentation of plaques through a Geometric Active Contours method. The variability in segmentation between our algorithm and different human operators appears comparable to the variability between human operators.