MEASUREMENT AND MODELING OF DEPTH CUE COMBINATION - IN DEFENSE OF WEAK FUSION

Various visual cues provide information about depth and shape in a sce ne. When several of these cues are simultaneously available in a singl e location in the scene, the visual system attempts to combine them. I n this paper, we discuss three key issues relevant to the experimental analysis of depth cue combination in human vision: cue promotion, dyn amic weighting of cues, and robustness of cue combination. We review r ecent psychophysical studies of human depth cue combination in light o f these issues. We organize the discussion and review as the developme nt of a model of the depth cue combination process termed modified wea k fusion (MWF). We relate the MWF framework to Bayesian theories of cu e combination. We argue that the MWF model is consistent with previous experimental results and is a parsimonious summary of these results. While the MWF model is motivated by normative considerations, it is pr imarily intended to guide experimental analysis of depth cue combinati on in human vision. We describe experimental methods, analogous to per turbation analysis, that permit us to analyze depth cue combination in novel ways. In particular these methods allow us to investigate the k ey issues we have raised. We summarize recent experimental tests of th e MWF framework that use these methods.