基于反向映射法逆向描述数字散斑变形的方法  

Reverse mapping for generating simulated deformed speckle patterns

作　　者：毛建国[1] 张佩泽[1] 沈峘[1] 程百顺 梁中汉 

机构地区：[1]南京航空航天大学能源与动力学院,江苏南京210016

出　　处：《光电子．激光》2015年第12期2433-2439,共7页Journal of Optoelectronics·Laser

基　　金：航空科学基金(20120952022);中央高校基本科研业务专项基金(NS2014020)资助项目

摘　　要：考虑到现有制备模拟散斑图方法系统误差较大、生成方法复杂和编程实现困难等不足,提出一种基于反向映射法的变形散斑图生成方法,将变形模式进行反向变换,并利用变形过程中图像灰度不变的特性,生成变形后的模拟散斑图。仿真分析表明对于相同数字图像相关(DIC)法计算参数,本文的反向映射法生成的变形散斑图具有更高的计算精度,因而提高了DIC法计算结果的可信度;并且,本文的反向映射法具有易于理解和易编程实现等优点。Digital image correlation （DIC） technology is an optical method which is developed to measure the deformation characteristics of the specimen surface in experimental mechanics. Usually there are all kinds of factors affecting the calculation of digital image correlation method. In order to study the affecting factors, simulated speckle patterns with controlled deformation are applied on DIC calculation accuracy analysis. However, existing methods for generating simulated speckle images have some deficiencies, such as introducing systematic error, complex algorithm, and being hard to realize by programming. A novel reverse mapping based method is proposed in this paper to generate simulated speckles. This new method assumes that point coordinates of the deformation speckle image are already known. Then the point coordinates of the speckle image before deformation can be gotten by reversely transforming the deformation mode. Based on image intensity invariance during the deformation and the already generated speckle image before deformation,this new method extracts the intensity values of the image before deformation to generate the speckles after deformation. The simulation analyses validate that, with the same DIC calculation parameters, speckles generated by reverse mapping method present higher calculation accuracy. And this new algorithm is easy to understand and realize.

关 键 词：数字图像相关(DIC) 模拟散斑图 反向映射法 光学测量 

分 类 号：TP391[自动化与计算机技术—计算机应用技术] O348[自动化与计算机技术—计算机科学与技术]