Example-Based Composite Sketching of Human Portraits

Creating a portrait in the style of a particular artistic tradition or in the personal look of a particular artist is a difficult problem. Elusive to codify algorithmically, the nebulous qualities which combine to form artwork are often well captured using example-based approaches. These methods place the artist in the process, often during system training, in the hope that their talents may be tapped. Example based methods do not make this problem easy, however. Examples are precious, so training sets are small, reducing the number of techniques which may be employed. We propose a system which combines two separate but similar subsystems, one for the face and another for the hair, each of which employs a global and a local model. Facial exaggeration to achieve the desired stylistic look is handled during the global face phase. Each subsystem uses a divide-and-conquer approach, but where the face subsystem decomposes into separable subproblems for the eyes, mouth, nose, etc., the hair needs to be subdivided in a relatively arbitrary way, making the hair subproblem recomposition an important step which must be handled carefully with a structured model and a detailed model.