Investigation of potential benefits of stereoscopic video for visual detection in turbid underwater environments

Abstract

This study examines potential advantages of using stereoscopic video for underwater inspection under turbid conditions, a task which is affected also by low illumination and camouflaging. An overview is given of earlier research on the theoretical effects of these factors on visual perception. An experiment was carried out to investigate performance using stereoscopic video in a simulated underwater inspection task involving detection of a camouflaged object, at four turbidity levels and three camera separation levels. In general, it was found that detection rate and sensitivity were consistently and significantly better using stereoscopic compared to monoscopic video. Of equal importance was the discovery of an interaction between camera and turbidity treatments, suggesting that use of stereoscopic video should decelerate performance degradation for increasing turbidity. It was also found that diminished display brightness due to the use of shuttering glasses detracted very little from performance with monoscopic video, implying that addition of stereo glasses should not offset the expected advantages of stereoscopic viewing. Finally, the magnitude of stereoscopic disparity was found to have only a slight effect on detection performance, implying that a minimal level of disparity is sufficient for overcoming turbidity significantly.