Digital volume correlation in an environment with intensive salt-and-pepper noise and strong monotonic nonlinear distortion of light intensity

作者：Tu, Peihan; Bai, Yulei; Xu, Weichao; Dong, Bo; Ye, Shuangli; Yang, Qiyu; Zhou, Yanzhou^*

来源：Optica Applicata, 2017, 47(2): 209-223.

DOI：10.5277/oa170204

• digital volume correlation
• correlation function
• salt-and-pepper noise
• nonlinear effects

Digital volume correlation is an image-based technique for internal 3D displacement and strain fields measurement or analysis widely used in the field of experimental mechanics. A widely used correlation criterion) of digital volume correlation is Pearson correlation function, which suffers from the problem of the acquired data being contaminated by salt-and-pepper noise and monotonic nonlinear distortion of the light intensity. In this work, a 3D correlation function called the Spearman correlation function is used to deal with those interferences. A numerical experiment shows that the performance of Spearman correlation function using integer-pixel registration in an environment with 10% salt-and-pepper noise is better than that of Spearman and Pearson correlation functions using sub-pixel registration in an environment with 1% salt-and-pepper noise. As the light intensity distortion is significant, the error of Pearson correlation function is considerable; meanwhile, the error of Spearman correlation function is small. In conclusion, Spearman correlation function is, in particular, practical and useful in digital volume correlation.

• 出版日期2017
• 单位广东工业大学; 武汉大学