High resolution spectral analysis of images using the pseudo-Wigner distribution

Abstract

Several methods for the computation of the discrete Wigner distribution (DWD) through the use of two-dimensional (2-D) analytic signals have been proposed, depending of the direction of the phase shift. Most of the methods cope with the problem of aliasing of the DWD by low-pass prefiltering the spectrum but reducing spatial frequency support. A new method for 2-D DWD free of aliasing and simultaneously increasing the spatial frequency support is proposed through the use of a new analytic signal. In this way, local spectral analysis for small window sizes can be accomplished improving the resolution but reducing cross terms and other interferences inherent in the DWD computation. For the three analytic images used in the comparison, the method proposed here also performs better than the other two for such tasks.