Abstruct-We consider the class of bilinear time-frequency representations (BTFR's) that are invariant (or covariant) to time shifts, frequency shifts, and time-frequency scalings. This " shift-scale invariant " class is the intersection of the classical shift-invariant (Cohen) class and the recently defined affine class. The mathematical description of shift-scale invariant BTFR's is in terms o...

In this paper we present a very effective method for texture segmentation and analysis using a local spectral method. The idea is to use a modular pattern detection in textured images based on the use of a Pseudo-Wigner Distribution (PWD) followed by a decorrelation procedure that consists of a principal component analyzer (for texture segmentation). The goal is to combine the advantages of a h...

This article demonstrates how time-frequency methods can be used in applications of image processing, such as monitoring, detecting inhomogeneities in textures and texture segmentation. A Pseudo Wigner Distribution (PWD) for 2D images free of aliasing and simultaneously increasing the spatial frequency support is defined through the use of a new analytic signal. In addition to that, cross-terms...

A.J.E.M. Janssen Philips Research Laboratories

This report is a 5-page quick summary on the most fundamental properties of the Wigner distribution. This document is structured as follows: in the first section the context is given: we introduce the fundamental issues of the time-frequency analysis and the role of joint time-frequencies distributions; then we enumerate the ideal requirements for such distributions. In the second section we sp...