Intensity-invariant local phase features based on Log-Gabor filters have been recently shown to produce highly accurate localizations of bone surfaces from three-dimensional (3-D) ultrasound. A key challenge, however, remains in the proper selection of filter parameters, whose values have so far been chosen empirically and kept fixed for a given image. Since Log-Gabor filter responses widely ch...

In this paper, the two dimensional (2-D) frequency sampling fllter system function described in reference [1] is further developed for frequency sampling filters that have linear phase and frequency sampling fllters that have linear phase and fourfold symmetry. Theresulting system functions are computationally more efficient for implementing frequency sampling filters with linear phase and freq...

The analytic signal is one of the most capable approaches in onedimensional signal processing. Two-dimensional signal theory suffers from the absence of an isotropic extension of the analytic signal. Accepting the fact that there is no odd filter with isotropic energy in higher dimensions, one tried to circumvent this drawback using the one-dimensional quadrature filters with respect to several...

Intensity-invariant local phase-based feature extraction techniques have been previously proposed for both soft tissue and bone surface localization in ultrasound. A key challenge with such techniques is optimizing the selection of appropriate filter parameters whose values are typically chosen empirically and kept fixed for a given image. In this paper we present a novel method for contextual ...

It is often assumed that a two-stage filter-process is involved in the coding of visual contours. In the first stage the contour is coded by localized luminance filters selective for, among other dimensions, orientation and spatial frequency. A second stage then integrates the outputs of these local luminance filters over space. In the experiments described here we address the issue of which sp...