The perception of 3D shape from texture based on directional width gradients

A new computational analysis is described that is capable of estimating the 3D shapes of continuously curved surfaces with anisotropic textures that are viewed with negligible perspective. This analysis assumes that the surface texture is homogeneous, and it makes specific predictions about how the apparent shape of a surface should be distorted in cases where that assumption is violated. Two psychophysical experiments are reported in an effort to test those predictions, and the results confirm that observers' ordinal shape judgments are consistent with what would be expected based on the model. The limitations of this analysis are also considered, and a complimentary model is discussed that is only appropriate for surfaces viewed with large amounts of perspective.