Signal analysis with classical Gabor frames leads to a fixed time-frequency resolution over the whole time-frequency plane. To overcome the limitations imposed by this rigidity, we propose an extension of Gabor theory that leads to the construction of frames with time-frequency resolution changing over time or frequency. We describe the construction of the resulting nonstationary Gabor frames a...

This paper discusses iris recognition, which is accepted as one of the best biometric methods for identifying an individual. A comparative analysis is done for eight algorithms, namely DCWT, FWT, SWT, CWT, DB, Complex dual tree, Haar wavelet and Wavelet packet for extracting the feature from iris image. Extracting the iris features of the image is still inconceivable as the existing algorithms ...

Recent research on texture synthesis suggests that characterisation of those properties of textures to which human observers are sensitive may be provided by the histograms of the coefficients of a wavelet decomposition. In this study we examined the properties of wavelet histograms that affect texture discrimination by measuring observer sensitivity to differences in the wavelet histograms of ...

ÐWe propose a method for automatically classifying facial images based on labeled elastic graph matching, a 2D Gabor wavelet representation, and linear discriminant analysis. Results of tests with three image sets are presented for the classification of sex, arace,o and expression. A visual interpretation of the discriminant vectors is provided. Index TermsÐComputer vision, face recognition, fa...

In this paper we compare different transmultiplexer structures with respect to the ISI/ICI occuring for typical time–invariant channels. In particular we consider wavelet–type, Gabor-type (the class containing OFDM and DMT) and Wilson-type (offset-QAM/OFDM) transmultiplexer. We present both theoretical results (based on a recently developed perturbation theory of coherent Riesz bases) and numer...

The paper proposes a new iris coding method based on Zak-Gabor wavelet packet transform. The essential component of the iris recognition methodology design is an effective adaptation of the transformation parameters that makes the coding sensitive to the frequencies characterizing ones eye. We thus propose to calculate the between-to-within class ratio of weakly correlated Zak-Gabor transformat...

The Wavelet Transform is a multiresolution analysis tool commonly applied to texture analysis and classification and also Wavelet based pre-processing is a very successful method providing proper Image Enhancement and remove noise without considerable change in overall intensity level. The Wavelet Transform mostly used for contrast enhancement in noisy environments. In this paper we propose a t...

In the early days of Gabor analysis it was a common to say that Gabor expansions of signals are interesting due to the natural interpretation of Gabor coefficients, but unfortunately the computation of Gabor coefficients is costly. Nowadays a large variety of efficient numerical algorithms exists (see [28] for a survey) and it has been recognized that stable and robust Gabor expansions can be a...