Stereopsis from disparity of complex grating patterns.

Vertical grating patterns containing more than one spatial frequency component were presented stereoscopically. The depth percepts resulting from differences in relative horizontal position (or phase) in left- and right-eye views were measured using a depth-matching procedure. When the frequency components were similar in contrast, the depth percept was mediated by the overall disparity of the compound. However, a relatively low contrast component could make no contribution to the depth percept while still remaining clearly visible in the grating pattern. When two frequency components were equal in contrast but carried different individual disparities derived from local edge and spatial frequency information, the resulting percept contained multiple depth planes.