Research And Implementation Of Computer-Aided Photographic Superimposition Technique

The technology of photographic superimposition is one important direction of personal identification which based on skull. Using the photographic superimposition to identify a body without a name, it can provide some clues for solving a case and scientific proof for judicial review. It is an important personal identification way in forensic anthropology.Most of present superimposition are realized by taking photos. This thesis mainly research on computer-aided photographic superimposition Technique, study how to make a 3D skull and a 2D photo be superimposition in computer. This paper mainly include:1) Definition of identification features. Based on forensic anthropology and anatomy, we analyze features used in superimposition, and then select four items, fifty-five features, which be based on by computer-aided photographic superimposition.2) Study how to adjust the skull according the photo in computer, and how to avoid the influences from the distance of focus and photography.3) To satisfy the specific requirements of photographic superimposition, we should preprocess the 2D-Photo, including image boosting, image scaling without loss and image adjusting.4) Extract the features on face and skull. Study how to get contour of head and other characters on face and skull.5) Study skull-photo registration. Based on traditional image registration, we apply it to photographic superimposition, given the specific detail steps.Besides these theory researches, we also built a photographic superimposition system, which named PhotoSkull, using Visual C++ and OpenGL on the PC platform, which can preprocess images, sign the feature points on skull and photo and then register the skull and photo. A lot of tests tell that the skull-photo a registration using the algorithms in this thesis can get high precision and reliability.