Anais do IX SIBGRAPI'96 (1996), 95-102

Natural Photometric Stereo?

Abstract:

The human brain seems to have the ability of inferring shape from the binocular fusion of some kinds of monocular images. Recently, we have observed that photometric stereo (PS) images, which are monocular images obtained under different illuminations, produce a vivid impression of depth, when viewed under a stereoscope. Lately, we have found that the same is true of pairs of images obtained in different spectral bands. Employing an optical-flow based photometric stereo algorithm on a type of ``colour separated images'', which have been so produced as to emulate the kinds of records generated by the photosensitive cells in the human retina, we have been able to obtain depth estimates from them. This has led us to speculate on the possibility that a process similar to PS could work on the human visual system. Here we present our claim for a natural photometric stereo process, invoking some physical and biological arguments, along with experimental results, that could support it.

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