'Proto-rivalry': how the binocular brain identifies gloss

Alexander A. Muryy, Roland W. Fleming, Andrew E. Welchman
2016 Proceedings of the Royal Society of London. Biological Sciences  
Visually identifying glossy surfaces can be crucial for survival (e.g. ice patches on a road), yet estimating gloss is computationally challenging for both human and machine vision. Here, we demonstrate that human gloss perception exploits some surprisingly simple binocular fusion signals, which are likely available early in the visual cortex. In particular, we show that the unusual disparity gradients and vertical offsets produced by reflections create distinctive 'protorivalrous' (barely
more » ... le) image regions that are a critical indicator of gloss. We find that manipulating the gradients and vertical components of binocular disparities yields predictable changes in material appearance. Removing or occluding proto-rivalrous signals makes surfaces look matte, while artificially adding such signals to images makes them appear glossy. This suggests that the human visual system has internalized the idiosyncratic binocular fusion characteristics of glossy surfaces, providing a straightforward means of estimating surface attributes using low-level image signals.
doi:10.1098/rspb.2016.0383 pmid:27170713 pmcid:PMC4874713 fatcat:ekkt4dforrb2fpt2pxq3e3klc4