Abstract

R. J. Peters, T. N. Mundhenk, L. Itti, C. Koch, Contour-facilitation in a model of bottom-up attention, In: Proc. Society for Neuroscience Annual Meeting (SFN'03), Nov 2003. (Cited by 2)

Abstract: Previously we showed that interactions among overlapping orientation-tuned units could improve a bottom-up attention model in predicting human eye movement targets. We have now extended this work to address the question of how elongated contours affect saliency in natural scenes. We used a model of contour-facilitation based on putative long-range excitatory and inhibitory interactions among orientation-tuned units in early visual cortex. Each unit tends to excite other units that are nearly collinear, and inhibit those that are nearly parallel. We tested the model on artificial images such as arrays of Gabor patches with embedded implicit contours ('snakes'), as well as natural images such as outdoor photos and overhead satellite photos. Our results agree with previous psychophysical measurements of human observers' sensitivity to implicit contours such as Gabor snakes; we found that a basic bottom-up saliency model was completely blind to such contours, while an enhanced saliency model with contour-facilitiation module could consistently identify the embedded contour (left figure) as the most salient element in the image (right figure). Preliminary eyetracking results suggest that observers are less sensitive to high spatial-frequency contours in natural scenes.

Themes: Computational Modeling, Human Psychophysics, Model of Bottom-Up Saliency-Based Visual Attention, Human Eye-Tracking Research