Image Segmentation by Local Temporal Phase Differences

Abstract

Previous research has shown that flickering elements can be grouped on the basis of temporal phase differences. We investigated the spatial and temporal parameters that permit temporal phase segmentation. The stimulus consisted of a regular square lattice of Gaussian spots modulated in luminance against a background of 54 cd m −2 . Subjects identified one quadrant which was modulated 180° out of phase to the other quadrants. The modulation threshold was found for temporal frequencies between 4 and 30 Hz. Four Gaussian spot sizes with standard deviations from 0.05 to 0.43 deg were used: lattice spacing was proportional to dot size. ..