Image mapping and visual attention on a Sensory Ego-Sphere

The Sensory Ego-Sphere (SES) is a short-term memory for a robot in the form of an egocentric, tessellated, spherical, sensory-motor map of the robot's locale. This paper reports on: (1) the mapping to the SES of images with much higher resolution than the SES itself, and (2) the processing of visual attention on the SES. Described is a procedure to store spatially-overlapping imagery in the SES database and to generate and update a spherical composite of its visual contents. The composite image serves both as a visual map of the locale and as a representation of the local contents of the underlying full-resolution imagery. Visual attention enables fast alignment of overlapping images without warping or position optimization, since an attentional point (AP) on the composite typically corresponds to one on each of the collocated regions in the images. Such alignment speeds analysis of the multiple images of the area. Compositing and attention were performed two ways and compared: (1) APs were computed directly on the composite and not on the full resolution images until the time of retrieval. (2) The attentional operator was applied to all incoming imagery. Then the locations and values of the APs on the composite were computed as a function of those points within the corresponding regions of the collocated images. It was found that although the second method was slower, it produced consistent and, thereby, more useful APs.