Figure 12.

Stereo lines and endpoints. The vertical and oblique stereo line segments have the same horizontal disparity. The perpendicular disparity of the vertical line is the same as the disparity of the endpoints. The perpendicular and end disparities differ in the oblique line. The aperture problem could be solved, in the sense that the true-match disparity dominates, if the disparity of the two endpoints propagated across the linear extent between them, “filling-in” conflicting perpendicular disparities with the unambiguous disparities of 2-D stimulus features.