The perception of texture on folded surfaces.

Do judgments of texture similarity reflect surface texture or image texture? To find out, we had observers view a rectangular surface that was folded into three panels, much like a brochure. Each panel was textured with an oriented noise pattern and the observers' task was to determine which side panel matched the center panel in surface texture. Information about surface geometry was conveyed by binocular disparity and by the boundaries of the rectangular surface. We found that observers were often consistently wrong, selecting the texture that differed in the image and not on the surface. In sharp contrast, when observers judged the texture orientation on each panel individually, their judgments were accurate reflections of the surface texture. So even when observers can recover surface texture, their judgments of texture similarity may still be based on image texture.