Ballistics Image Processing and Analysis for Firearm Identification
Dongguang Li · InTech eBooks · 2009
Firearm identification is an intensive and time-consuming process that requires physical interpretation of forensic ballistics evidence. Especially as the level of violent crime involving firearms escalates, the number of firearms to be identified accumulates dramatically. The demand for an automatic firearm identification system arises. This chapter proposes a new, analytic system for automatic firearm identification based on the cartridge and projectile specimens. Not only do we present an approach for capturing and storing the surface image of the spent projectiles at high resolution using line-scan imaging technique for the projectiles database, but we also present a novel and effective FFT-based analysis technique for analyzing and identifying the projectiles. This system can make a significant contribution towards the efficient and precise analysis of firearm identification based on projectile ballistics. The study demonstrates that different types of land and groove marks generated by different guns have distinctive surface textures, and spectral analysis can be used to measure and identify these textures effectively. Never have we seen before, a method such as this, that can study line-scanned images of projectile specimens so effectively. The method can overcome the difficulties involved with descriptions in the normal spatial domain in identifying texture features formed by land and groove marks on the surface of projectiles. In recent years the Hough transform and the related Radon transform have received much attention. These two transforms are able to transform two dimensional images with lines into a domain of possible line parameters, where each line in the image will give a peak positioned at the corresponding line