Dynamic visual attention on the sphere

In this paper we present a computational model of dynamic visual attention on the sphere which combines static (intensity,chromaticity, orientation) and motion features in order to detect salient locations in omnidirectional image sequences while working directly in spherical coordinates. We build the motion pyramid on the sphere by applying block matching and varying the block size. The spherical motion conspicuity map is obtained by fusing together the spherical motion magnitude and phase conspicuities. Furthermore, we combine this map with the static spherical saliency map in order to obtain the dynamic saliency map on the sphere. Detection of the spots of attention based on the dynamic saliency map on the sphere is applied on a sequence of real spherical images. The effect of using only the spherical motion magnitude or phase for defining the spots of attention on the sphere is examined as well. Finally, we test the spherical versus Euclidean spots detection on the omnidirectional image sequence. (C) 2009 Elsevier Inc. All rights reserved.