Comparing facial line drawings with gray-level images: A case study on PHANTOMAS

Abstract

We report on an application of neural face recognition algorithms to a task with relevance to forensic investigations: The software tool PHANTOMAS (phantom automatic search) allows to compare facial line drawings (the German "Phantomzeichnung") with gray-level images of faces. In addition to normal (textual) database search actions, this software tool allows picture-to-picture searches. We present first results on the evaluation of a benchmark on this task. The ranking quality of PHANTOMAS allows to spot the true match belonging to a certain drawing on the average within the upper 2.7% of the database (N = 103). It is shown that this is comparable to the human performance on the same data material. Computation time makes it feasible to search online in large databases (N ≈ 10000). - With the same algorithm it is also possible to classify complex characteristica in faces or facial line drawings, which we demonstrate on the example of gender classification.