Analysis of low activity in dynamic speckle patterns

In this work we present to methods to evaluate activity in low dynamic speckle patterns. The first one is based on the behavior analysis of the vortices associated to the pattern. The other one consists in binarizing the speckle image. The speckle grain areas, also called islands, experiment displacements and deformations. The variations of the island features were analyzed with the aim of finding a correlation with the activity of the speckle pattern. Both methods were evaluated in numerical simulations and controlled experiments. From the obtained results, it was possible to conclude that the developed methods can be very useful for the analysis of low activity speckle patterns with some advantages with other methods.