• Frontiers of Optoelectronics
  • Vol. 1, Issue 3, 345 (2008)
Sihua FU1、*, Xuejun LONG1, Hui LIN2, and Qifeng YU1
Author Affiliations
  • 1College of Opto-electronic Science and Engineering, National University of Defense Technology, Changsha 410073, China
  • 2Institute of Space and Earth Information Science, The Chinese University of Hong Kong, Hong Kong 999077, China
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    DOI: 10.1007/s12200-008-0044-y Cite this Article
    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 Copy Citation Text show less

    Abstract

    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.
    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
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