Speckle activity images based on the spatial variance of the phase

HÉCTOR RABAL; NELLY CAP; MARCELO TRIVI; RICARDO ARIZAGA; ALEJANDRO FEDERICO; GUSTAVO GALIZZI; GUILLERMO KAUFMANN

APPLIED OPTICS

Optical Society of America

Año: 2006 vol. 45 p. 8733 - 8738

0003-6935

We propose the display of the local spatial variance of the temporal variations of the phase as an activity descriptor in dynamic speckle images. The spatial autocorrelation of the speckle intensity is calculated in sliding windows, and an estimation of the variance of the phase variations in each region of the sample is determined. The activity images obtained in this way depict some interesting features and in some cases they could be related to physical magnitudes in the samples. A simulation is presented, and examples corresponding to usual study cases are also shown, namely, fruit bruising and paint drying.