Abstract
Depth in a random dot stereogram is harder to perceive than that in a normal stereogram. Depth, however, is much easier to perceive when an outline is placed around the disparate region. This research uses a hybrid random dot stereogram in which a patch of dynamic random noise is set within a static field of random dots to test; the patch is binocularly correlated and binocular disparity is assigned to it. The normal (static) and the dynamic random dot stereogram are used to compare with the hybrid stereogram. Disparity thresholds to perceive depth are measured. Differences between them are as follows: a subjective contour, which is not luminance defined but is monocularly perceptible, appears around a dynamic patch; a dynamic patch, which has spatiotemporal changes, may stimulate the target detectors with not only disparity but motion; a dynamic random dot stereogram stimulates entirely with motion; a particular set of disparity detectors may be fatigued by a static stimulus. Experiments by the method of constant stimuli were conducted to measure disparity threshold. In each trial, a stereogram containing a central square in depth was presented. The refresh rate of dynamic change was 10 fps. Each dot was white on a black background. The results indicated our subjects could perceive smaller depth in the hybrid stereogram than that in the normal and the dynamic stereogram. Another experiment was conducted using a partially colored stereogram in which the central dots were green and the rest dots were white. The result indicated smaller depth could not be seen although the target could be seen monocularly. We noticed subjective contours in the hybrid (dynamic-static) stereogram appeared clearer than that in the partially colored stereogram. The visibility of subjective contours and/or motion stimulation might help people to see depth better.
Meeting abstract presented at VSS 2015