Model-based analysis of striation patterns in forensic science

We present a new image processing strategy that enables an automated extraction of signatures from striation patterns. To this end, a signal model is proposed that allows a suitable description of the interesting features of forensically relevant striation marks. To provide for a high image quality, several images of the same surface area are recorded under systematically varying conditions. The images obtained are then combined to an improved result by means of appropriate sensor fusion techniques. Based upon the signal model, the signal of interest is concentrated, and a compact representation of the grooves is obtained. To enable an efficient description of the relevant features even in the cases of deformed surfaces or curved striation marks, a straightening of the grooves is performed before. In the following, a meaningful signature describing the information of interest is extracted using the whole length of the grooves. This signature can be used for an objective evaluation of similarity of striation patterns.