Optical Imaging and Analysis of Firing-pin Marks for Ballistics Identification

Firing pin marks are most important forensic evidences in firearm identification, Howeveq there are no general guidelines available for optical imaging, processing, and analyzing the images of firing pin marks for firearm identification, In this respect, the further development for firearm identification is highly demanded from both theoretical and practical point of view. This paper aims to address the problem of firing pin marks identification. A novel approach is proposed for measuring the similarity of firing pin marks in terms of their co-occurrencefeature descriptors. In doing so, the markings on the surface of cartridge case are captured by a CCD camera. After extracting the firing pin imagesn we calculate the co-occurrence feature sets of the firing pin images. Then we can classify the firing pin images based on the relative distances between sample images. The experimental results indicate that the firing pin marks can be preciously classified in terms of their co-occurrence features.