基于自适应互信息测度法的弹壳比对  

Cartridge Case Comparison Based on Adaptive Mutual Information Measure Method

作　　者：李平[1,2] 魏仲慧[1] 何昕[1] 郭敬明[1,2] 乔培玉 

机构地区：[1]中国科学院长春光学精密机械与物理研究所,长春130033 [2]中国科学院研究生院,北京100049 [3]公安部沈阳消防研究所,沈阳110034

出　　处：《光电工程》2012年第12期42-48,共7页Opto-Electronic Engineering

摘　　要：为了实现枪击案件的有效快速侦破,设计了弹痕三维纹理比对系统。本文主要是对撞针在弹壳尾部上的压痕进行比对,以确定两弹壳是否发自同一支枪。首先根据弹壳尾部为一圆形的先验知识,对撞针处的压痕进行质心计算,把其中一个弹壳进行绕圆心旋转,使两撞针质心与各自的圆心连线平行,然后进行基于体素的互相关测度计算。为了提高比对的精度,提出了利用自适应的变系数迭代法进行互相关测度计算。实验结果表明,当两个弹壳发自同一支枪时,互相关测度值的最大值能够提高30%以上,平均提高12%以上。比对结果稳定可靠,能够满足弹痕比对系统的要求。In order to realize rapid detection for the shootings effectively, a cartridge case compared system of the 3D topography is established. We compared the indentation of the firing pin which remained on the cartridge cases to determine whether the cartridge cases fired from the same gun. First, according to the prior knowledge that tail of cartridge case is circle, we calculated the center of mass which is the indentation of firing pin, rotated a cartridge case around the center of circle, and made the connections of center of mass of two firing pins to center of circle parallel. Then, the cross-correlation measure was calculated based on voxel. In order to improve the matching accuracy, iterative algorithm on adaptive variable coefficients was proposed for calculation of cross-correlation. Experimental results indicate that when the two cartridges are fired from the same gun, the maximum of cross-correlation measure is improved more than 30%, and the average is more than 12%. The result of comparison is stable and reliable; which can satisfy the requirement of the bullets comparison system.

关 键 词：弹壳比对 三维信息 互信息测度 自适应变系数 

分 类 号：TP394.1[自动化与计算机技术—计算机应用技术] TH691.9[自动化与计算机技术—计算机科学与技术]