As an alternative to the intensity correlation used in conventional speckle metrology, we propose a new technique for displacement observation that is based on spatial-signal-domain phase-only correlation and that makes use of the pseudophase of the complex analytic signal generated from a Hilbert-filtered speckle pattern. Experimental results are presented that demonstrate the validity and the advantage of the proposed signal-domain phase-only correlation technique over both the conventional intensity correlation technique and the spatial-frequency-domain phase-only correlation technique.
© 2005 Optical Society of America
(070.4550) Fourier optics and signal processing : Correlators
(100.4550) Image processing : Correlators
(100.5070) Image processing : Phase retrieval
(120.6150) Instrumentation, measurement, and metrology : Speckle imaging
Wei Wang, Nobuo Ishii, Steen G. Hanson, Yoko Miyamoto, and Mitsuo Takeda, "Pseudophase information from the complex analytic signal of speckle fields and its applications. Part I: Microdisplacement observation based on phase-only correlation in the signal domain," Appl. Opt. 44, 4909-4915 (2005)