Frontiers of Optoelectronics, Volume. 1, Issue 3, 345(2008)
Fringe-contoured-window sine/cosine filter for saw-tooth phase maps in ESPI
In electronic speckle pattern interferometry (ESPI), because saw-tooth phase map obtained by phaseshifting is inherently full of speckle noise, noise reduction should be carried out to suppress high-level noise before it is unwrapped. In accordance with the feature of the saw-tooth phase map, an adaptive filter method combining the classical sine/cosine filter and the fringe orientation information of the phase map is developed. A fringe orientation map is first generated from the saw-tooth phase map, and then a fringe-contoured window is derived accordingly. Finally, filtering is carried out within the window. Compared with existing filters, it has a better performance on phase jump information preservation without any blurring effect on phase distribution provided that filtering is implemented on the equal-phase window. Moreover, its capability for noise reduction is more powerful. The effectiveness and advantages of the novel filter have been also verified by both simulated and real saw-tooth phase maps.
Get Citation
Copy Citation Text
Sihua FU, Xuejun LONG, Hui LIN, Qifeng YU. Fringe-contoured-window sine/cosine filter for saw-tooth phase maps in ESPI[J]. Frontiers of Optoelectronics, 2008, 1(3): 345
Received: --
Accepted: --
Published Online: Nov. 6, 2012
The Author Email: FU Sihua (fusihua2002cn@hotmail.com)