Fast and Robust Digital Image Spearman's Rho Correlation for Displacement Measurement

The robustness and computational efficiency of digital image correlation (DIC) are two key influencing factors for displacement field measurement applications. Especially when the speckle images contaminated by salt-and-pepper noise, it is difficult to obtain reliable results using traditional DIC methods. Digital Spearman’s Rho Correlation (DISRC), as a new technique, has certain but incurs high load computing subset ranks. It found that DISRC can tolerate up 15% noise level theoretically analyzing mean character Rho. Meanwhile fast scheme proposed in which parallelization adopted precomputing rank accelerate DISRC. simulation indicate about 60 times faster than original one, almost same between them. not only gives well zero-mean normalized cross-correlation (ZNCC) without any also 20% simulations. A case study verifies result better ZNCC smaller amounts noise. conclusion strong anti-interference very important application under complex environment, an effective way