An Overt Visual Attention Mechanism Based on Saliency Dynamics

A visual overt attention mechanism is presented in this paper. Our algorithm chooses the next fixation point for a robot mobile camera in order to track several objects around the robot simultaneously, even if the whole set of them can not be covered by the same camera image. Our approach is based on two related measurements, liveliness and saliency, that dynamically evolve depending on the image observations and the camera movements. The attention is shared among exploring the surroundings for salient features, reobserving the tracked objects and other task-dependent points to look at. A winner-takes-all competition provides a flexible time sharing behavior with natural appearances of new objects, disappearances and inhibition of return. It also accepts top down features to look for and different priorities for them. Several experiments have been carried out with a real Pioneer robot endowed with mobile camera and are also described.