数字散斑相关方法全场变形快速测量

Full field deformation fast measurement based on digital image speckle correlation

采用亚像素初始值结合插值系数双缓存方法提高反向组合算法计算效率,用于数字散斑相关方法全场变形测量。首先根据反向组合算法迭代特性,采用相关系数拟合法得到亚像素位移初始值代入反向组合算法,加速单点匹配迭代收敛速度;然后由全场变形计算特点,采用插值系数双缓存方法提高全场亚像素变形计算效率。本算法在单点匹配时,速度加快了10.33%;全场变形计算时,速度提升了24.93%。由此证明本算法能有效提高基于反向组合算法的数字散斑相关方法全场变形计算效率。

To improve the effectiveness of the inverse compositional Gauss-Newton（ IC-GN） algorithm which is applied to digital speckle correlation method（ DSCM）,initial gauss with sub-pixel accuracy and double cached tables of interpolation coefficient（ DTIC） are considered. Firstly, according to the characteristic of IC-GN algorithm which is essentially an optimization iteration method,a sub-pixel initial guess is taken as the start point of IC-GN. The speed of IC-GN of single point is accelerated. Then,the DTIC is used to accelerate the calculation efficiency of full field sub-pixel deformation. The experimental results verify that the proposed method generates similar results,with the efficiency is about 10. 33% and 24. 93% improvement on single point and full deformation field as IC-GN. So the proposed method is expected to be an efficiency way to improve the efficiency of full field deformation calculation.