Firearm identification based on rotation invariant feature of cartridge case

This paper, proposes firearm identification method based on rotation invariant feature of cartridge case image. The rotation invariance feature is represented by the absolute value of Fourier coefficients of polar image of cartridge case on circles with different radii. The absolute value of Fourier coefficients is considered as the individual feature of the particular gun. Finally, the firearm can be identified by the distance between the absolute value of Fourier coefficients obtained from the reference cartridge case and the cartridge case to be identified. The firearm identification experiments are given to show the effectiveness of the proposed method.