Automatic comparison of bullet marks by matching 3-D topography of different bullets
Wei Zhong-hui · Harbin Gongcheng Daxue Xuebao/Journal of Harbin Engineering University · 2013
In order to achieve automatic comparison of bullet marks through computer technology,a method to match 3-D topography of different bullets was proposed.First,a proven threshold function of wavelet was used to de-noise the database of the collected 3-D bullet mark information.Second,as in accordance with the vertical direction of the bullet procedure,after de-noising the designed one-dimensional Gaussian filter was used to extract useful information to replace the classical two-dimensional Gaussian filter,and to reduce the loss of information.Finally,after the rotation and translation,we were able to retrieve useful bullet marks near the edge of each bullet,and calculate the cross-correlation measure between two different bullets to identify whether they were fired by the same type of firearm.Experiments show that the proposed method was capable of extracting 3D topography of bullets and realize the automatic comparison of bullet marks through programming.The accuracy rate of the identification was no less than 98% based on the current database.