Synthesis of Photographic Quality Facial Composites using Evolutionary Algorithms

A facial composite system is described for use in criminal investigations which has distinct advantages over current methods. Unlike traditional feature based methods, our approach uses both local and global facial models, allowing a witness to evolve plausible, photo-realistic face images in an intuitive way. The basic method combines random sampling from a facial appearance model (AM) with an evolutionary algorithm (EA) to drive the search procedure to convergence. Three variants of the evolutionary algorithm have been explored and their performance measured using a computer simulation of a human witness (virtual witness). Further system functionality, provided by local appearance models and transformations of the appearance space which respectively allow both local features and semantic facial attributes to be manipulated, is presented. Preliminary examples of composites generated with our system are presented which demonstrate the potential superiority of the evolutionary approach to composite generation.