A selective phase filter based on speckle decorrelation

A new phase filter technique based on the speckle decorrelation analysis is proposed on this paper to remove the noise from the phase maps. The phase maps are extracted from speckle interferometry static measurements using the four phase shifted intensities, with the constant phase step of π/2. The speckle descorrelation points are then selected based on the average phase step of the reference and deformation states phase maps. The recursive average phase filter technique is applied to the phase maps and only the speckle decorrelation points are updated in each iteration, preserving the correct phase information. The results of the present method are compared with the well-known phase filters. It was found that the proposed method presents higher performance, particularly when dealing with phase maps which have low signal-to-noise ratio