17. Quality Assessment of Speckle Patterns by Estimating RMSE

The primary objective of this proceeding is to properly assess the quality of speckle patterns utilized in digital image correlation (DIC). Since a good pattern should associate with a small measurement error, the overall error can be used to assess the quality of a speckle pattern. The overall error consists of interpolation bias, noise-induced bias, and uncertainty due to image noise. Considering all these factors, this proceeding presents two assessment parameters, the maximum and the quadratic mean of the overall error respectively, to characterize the quality of a speckle pattern. Analytical formulae of proposed parameters were derived; estimating strategy was developed. Numerical simulations show the efficiency of proposed estimating strategy and demonstrate that the proposed parameters are more preferable than existing parameters due to the consideration of both systematic errors and random errors.