In the last decade, several studies have shown that the robustness of ASR systems can be increased when 2D Gabor filters are used to extract specific modulation frequencies from the input pattern. This paper analyzes important design parameters for spectro-temporal features based on a Gabor filter bank: We perform experiments with filters that exhibit different phase sensitivity. Further, we an...

For high-speed low-complexity filter design, it is common practice to constrain the filters' coefficients to be power-oftwo or a sum of powers-of-two terms (P2), avoiding the full multiplication. Tapped interconnection of different sub-filters are sometimes used to enhance ripple and stop-band attenuation performances. An extension of the simple cascade architectures, suitable for hardware impl...

Many applications can benefit from the use of pupil filters for controlling the light intensity distribution near the focus of an optical system. Most of the design methods for such filters are based on a second-order expansion of the Point Spread Function (PSF). Here, we present a new procedure for designing radially-symmetric pupil filters. It is more precise than previous procedures as it co...

In stereovision, the use of frequency domain methods raises the problems of the choice of a family of filters and a strategy to use it. This paper compares three families : Gabor filters, finite prolate spheroidal sequences and Weng's Windowed Fourier of Gaussian (WFG). Then a comparison between two strategies is done : an image-based choice of filters and the use of a "complete" subset of filt...

Wavelet filters can be parametrized to create an entire family of different wavelet filters. We discuss wavelet filter parametrization as a means to add security to wavelet based watermarking schemes. We analyze the influence of the number of filter parameters and use non-stationary multi-resolution decomposition where different wavelet filters are used at different levels of the decomposition....

Termites construct complex mounds that are orders of magnitude larger than any individual and fulfil a variety of functional roles. Yet the processes through which these mounds are built, and by which the insects organize their efforts, remain poorly understood. The traditional understanding focuses on stigmergy, a form of indirect communication in which actions that change the environment prov...

one of the principles for designing and using the various units of water treatment plants is ability of assigning and predicting performance of those units in different and various conditions that could be checked by making pilot and could be modeled by means of available programs and software such as artificial neural network. at this study a model provided for predict performance of pressure ...