A computational model is proposed for spatial orientation processing beyond the initial stage of linear filtering in visual cortex. The model accounts for orientation pop-out, edge location and orientation, and bar location and orientation. It naturally extends to higher order orientation symmetries. The model is consistent with much of the current… (More)
We introduce a novel formulation of the Circle Hough Transform that we call the Coherent Circle Hough Transform. The technique uses phase to code for radii of circles. The usual simplifications of the Circle Hough Transform (CHT) are used in which lines pointing away from edge points are plotted rather than circles. Intersections of these "spokes"… (More)
Two techniques are presented for corner detection. First, a band of filters are applied with equal radial spatial frequency, but different orientation preferences locally in the image domain. From the energy response, a linear Fourier transform is taken to give confidence measures of both "cornerness" and "edgeness. Second, we consider a multi-local spatial… (More)
A novel approach for rendering time-varying data based on the Shear-Warp factorisation is presented. Reduction in storage space is achieved by detecting the changed areas within each volume and compressing them. Time-coherence is exploited by detecting and rendering the changes in every volume while spatial-coherence is exploited by utilising a data… (More)
We extend the principle of phase-based techniques for measuring optical flow and binocular disparity to multiple motion estimation. We analyse multiple optical flows by estimating phase gradients (instantaneous frequencies) from a set of independent bandpass quadrature filter pairs. Our approach is similar to that of Shizawa and Mase , in which… (More)
We describe the characterisation of an application kernel on a parallel system of two processors. The application kernel is a one-dimensional Fast Fourier Transform (FFT) and the processors used are two T800 transputers. Analytical expressions for the \execution time" for a single and two processors are discussed and used to obtain the performance measure.