Least-squares phase estimation with multiple parameters in phase-shifting electronic speckle pattern interferometry.
We have developed an accurate and robust phase-estimation method in phase-shifting electronic speckle pattern interferometry. Unlike other methods that assume a constant phase within a fitting window, our method treats the phase variation with a gradient. A cost function that can utilize the information of pixel positions is formulated on the basis of a least-squares criterion. Powell's iteration method is applied to it to derive the phase and its gradient. An automatic consistency-checking routine and an algorithm that improves the initial guess of the iteration are developed for severe situations with large noise and steep phase variations.
Yun
Hae Young
HY
Department of Physics, Pohang University of Science and Technology, Pohang 790-784, Korea.
Hong
Chung Ki
CK
Chang
Seok Won
SW