Acta Optica Sinica, Volume. 27, Issue 5, 864(2007)
Fringe-Contoured-Window Sine/Cosine Filter for Saw-Tooth Phase Maps of Electronic Speckle Pattern Interferometry
In electronic speckle pattern interferometry (ESPI), the saw-tooth phase map obtained by the phase-shifting technique is inherently full of speckle noise. Noise reduction must be carried out to suppress the high-level noise before it is unwrapped. In accordance with the feature of the saw-tooth phase maps, an adaptive filter is developed combining the classical sine/cosine filter and the fringe orientation information of the saw-tooth phase map. Fringe orientation map is firstly generated from the saw-tooth phase map, and then the fringe-contoured-window is derived accordingly. Finally, the filtering is carried out within the window. Comparing with existed filters, it has a better performance on phase jump information preservation and does not have any blurring effect on the phase distribution providing the filtering is implemented on the equal-phase window. Moreover, its capability of noise reduction is more powerful. The effectiveness and advantages of the novel filter have been verified by both simulated and real saw-tooth phase maps.
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[in Chinese], [in Chinese], [in Chinese], [in Chinese]. Fringe-Contoured-Window Sine/Cosine Filter for Saw-Tooth Phase Maps of Electronic Speckle Pattern Interferometry[J]. Acta Optica Sinica, 2007, 27(5): 864