We consider a new application of the normalized Hilbert-Huang transform to extract directly the phase from a single fringe pattern. We present a technique to provide, with good accuracy, the phase distribution from a single interferogram without unwrapping step and this by a new exploitation of the analytic signal corresponding to each intrinsic mode function, resulting from onedimensional empirical mode decomposition of the fringe pattern. A theoretical analysis was carried out for this technique, followed by computer simulations and a real experimental fringe pattern for verification.

The purpose of the present work is the use of the Phase evaluation CWT algorith m to extract the phase from squeezing interferogram. The squeezing interfero metry technique generates a spatial carrier interferogram named squeezed interferogram by numerical co mbination of M shifted fringes patterns. The M shifted fringes patterns are digitally generated fro m co mb ination of t wo π/2 shifted fringe patterns. Fro m squeezed interferogram the phase is extracted in wavelet domain using CWT algorith m which leads directly to the phase distribution without the complex step of phase unwrapping. Simu lated fringe pattern are used to test our technique and real fringe pattern are used to improve the accuracy of this technique.

The purpose of the present work is the use of squeezing interferometry Technique to provide an optical phase mapping from DSPI fringes. The main advantage of this technique is to demodulate by means of a quadrature Gabor filter, a single carrier-frequency fringe pattern formed from intermixing M shifted fringe patterns that are synthetised numerically by the combination of a primary interferogram and its quadrature, which leads directly to the phase without any speckle denoising algorithm, and this after unwrapping the phase with a standard phase unwrapping algorithm and using a simple median filter to smooth the result. This approach was tested on simulated interferograms for different speckle sizes and fringes densities; it was found that the procedure was able to give the result with a good accuracy for all these cases. An application of the proposed procedure to retrieve the phase for experimental fringes recorded from the thermomechanical study of the MOS power transistor is also presented.