Steerable filters have been used to analyze local orientation patterns in imagery. Such filters are typically based on directional derivatives, whose symmetry produces orientation responses that are periodic with period pi, independent of image structure. We present a more general set of steerable filters that alleviate this problem.

Particle filters provide a means to track the state of an object even when the dynamics and the observations are non-linear/nonGaussian. However, they can be very inefficient when the observation noise is low as compared to the system noise, as it is often the case in visual tracking applications. In this paper we propose a new two-stage sampling procedure to boost the performance of particle f...

This paper is a tutorial introduction to local linear and nonlinear filters. Their usefulness in a variety of common image processing tasks is discussed.

The construction of boundary filters without DC leakage for two-channel paraunitary FIR filter banks is considered. The design procedure is based on orthogonal boundary filters which are optimal in a weighted mean square error sense in the Fourier domain and on Householder transformation of boundary filter matrices. Simulation results are presented for boundary filters based on minimum-phase Da...

Wave digital filter (WDF) structures for high-speed narrow-band and wide-band filtering are introduced. The narrow-band filter is composed of a periodic model filter and one or several, possibly periodic, masking filters in cascade. Lattice and bireciprocal lattice WDF filters are used for the model and masking filters, respectively. The wide-band filter consists of a narrow-band filter in para...

Matching Short Wave InfraRed (SWIR) face images against a face gallery of color images is a very challenging task. The photometric properties of images in these two spectral bands are highly distinct. This work presents a new cross-spectral face recognition method that encodes both magnitude and phase of responses of a classic bank of Gabor filters applied to multi-spectral face images. Three l...

The eigenfilter method for digital filter design involves the computation of filter coefficients as the eigenvector of an appropriate Hermitian matrix. Because of its low complexity as compared to other methods as well as its ability to incorporate various time and frequency-domain constraints easily, the eigenfilter method has been found to be very useful. In this paper, we present a review of...

A new approach to local nonlinear image restoration is described, based on approximating functions using a regular grid of points in a many-dimensional space. Symmetry reductions and compression of the sparse grid make it feasible to work with twelve-dimensional grids as large as 2212. Unlike polynomials and neural networks whose ltering complexity per pixel is linear in the number of lter coe ...

We consider two content-based music retrieval problems where the music is modeled as sets of points in the Euclidean plane, formed by the (on-set time, pitch) pairs. We introduce fast filtering methods based on indexing the underlying database. The filters run in a sublinear time in the length of the database, and they are lossless if a quadratic space may be used. By taking into account the ap...

One of the main advantages of the linear-phase FIR filters over their IIR counterparts is the fact that there exist efficient algorithms for optimizing the arbitrary-magnitude FIR filters in the minimax sense. In case of IIR filters, the design of arbitrary-magnitude filters is usually time-consuming and the convergence to the optimum solution is not always guaranteed. The most efficient method...