Correlation-based pointwise processing of dynamic speckle patterns is proposed for spatial characterization of activity in a sample. The result is a set of 2D activity maps of the estimates of temporal correlation, or structure functions, at increasing time lags. Pointwise computation provides spatial resolution, limited by the pixel period of the optical sensor used for acquisition of the speckle patterns. Pointwise normalization of the estimates solves the problem with the nonuniform illumination and varying reflectivity across the sample. The high contrast detailed activity maps obtained from processing of synthetic and experimental speckle patterns confirms efficiency of the proposed approach.
© 2013 Optical Society of America
Instrumentation, Measurement, and Metrology
Original Manuscript: October 11, 2013
Revised Manuscript: November 23, 2013
Manuscript Accepted: November 25, 2013
Published: December 23, 2013
Elena Stoykova, Branimir Ivanov, and Tania Nikova, "Correlation-based pointwise processing of dynamic speckle patterns," Opt. Lett. 39, 115-118 (2014)