A defect inspection technique using polarized images for steel strip surface

Optimal Orientation Angle Configuration of Polarizers Exists in a 3 × 3 Mueller Matrix Polarimeter

“…If there are instrumental errors in the PSA, according to the discussion in Section 3.1, the intensity matrix I will involve some errors that will lead to errors in the solution of Equation (9). In this case, obviously, the error of the solution is relevant to the value of the coefficient matrix of Equation ( 9), i.e., A PSA .…”

“…In this case, obviously, the error of the solution is relevant to the value of the coefficient matrix of Equation ( 9), i.e., A PSA . That means there may exist an optimal orientation angle configuration of the PSA to minimize the potential error of the solution, which can be obtained from the perturbation analysis for Equation (9). The main principle of perturbation analysis is introducing perturbations into equations and analyzing the corresponding error of the solution.…”

“…The MM of the sample can be solved from Equation (8) if the constant matrix S in Equation ( 8) had been solved from Equation (9). Assuming S is a known parameter, then the solution of Equation ( 8) is only dependent on A PSG .…”

“…in which A PSG + ∆A PSG is the ground truth of A PSG ; ∆S C is the solution error of Equation (9). Similar to the analysis of the system composed of the PSA and the camera, an inequality can be deduced from Equations ( 17) and (18):…”

“…Optical measurement techniques based on polarization detection mainly focus on interactions between objects and polarized light. Because of the sensitivity of polarization states to morphological characteristics and physical and chemical properties of an object, polarimetry is applied as a precision measurement technology in various fields, such as cancer detection [1][2][3], characterization of biological tissue [4][5][6][7], defect inspection [8,9], etc.…”