Monday, October 8, 2007

Color stereoscopic images

Researchers in Israel have shown that we perceive 3-D color images even when we are presented with only one color image in a stereoscopic pair, with no depth perception degradation and only limited color degradation.

The latest print issue of SPIE's Optical Engineering dated August 2007 (Volume 46, Issue 8), has an interesting article on page (or I should write Citation Identifier, CID) 087003 with title Color stereoscopic images requiring only one color image. This paper is a beautiful piece of color psychophysics, in which the experiments were conducted both with a 1905 stereoscope and with a state of the art head-mounted display (HMD).

Stereoscopic images yield a much improved depth perception and operator performance. However, the amount of information transmitted is doubled. Obviously the left and right images contain a lot of redundant data, and various methods to compress motion images have been proposed to reduce the data stream, although a considerable computational cost hit must be taken.

The authors asked themselves, if the human visual system's fusion capability can be used to process color only of one eye's image, processing the image for the other eye just in luminance. This would cut down both device cost and data before any compression has been performed.

Indeed, the psychophysics results show that subjects perceived 3-D color images even when they were presented with only one color image in a stereoscopic pair, with no depth perception degradation and only limited color degradation in the form of a loss in vividness.