Knill D C
Department of Psychology, University of Pennsylvania, Philadelphia 19104, USA.
Vision Res. 1998 Jun;38(11):1683-711. doi: 10.1016/s0042-6989(97)00325-8.
In order to quantify the ability of the human visual system to use texture information to perceive planar surface orientation, I measured subjects' ability to discriminate planar surface slant (angle away from the fronto-parallel) for a variety of different types of textures and in a number of different viewing conditions. I measured the subjects' discrimination performance as a function of surface slant, field of view size and surface texture structure. I compared the subjects' performance with that of ideal observers derived for each of the available texture cues--texel position, scaling and foreshortening. The results can be summarized by four points: (i) subjects' discrimination performance improves dramatically with increasing surface slant, tracking the performance of the ideal observers; (ii) subjects can integrate texture information over a large range of visual angles; (iii) comparisons between human subjects and ideal observers show that the human observers rely to some degree on foreshortening information; and (iv) similar comparisons show that in using foreshortening information, subjects rely to some extent on a prior assumption of isotropy.
为了量化人类视觉系统利用纹理信息感知平面表面方向的能力，我测量了受试者在多种不同类型纹理以及多种不同观察条件下辨别平面表面倾斜度（与额状面平行的角度偏差）的能力。我测量了受试者的辨别性能，该性能是表面倾斜度、视野大小和表面纹理结构的函数。我将受试者的表现与针对每种可用纹理线索（纹理元素位置、缩放和缩短）得出的理想观察者的表现进行了比较。结果可归纳为四点：（i）随着表面倾斜度增加，受试者的辨别性能显著提高，追踪理想观察者的表现；（ii）受试者能够在大范围视角上整合纹理信息；（iii）人类受试者与理想观察者之间的比较表明，人类观察者在一定程度上依赖缩短信息；（iv）类似的比较表明，在使用缩短信息时，受试者在一定程度上依赖各向同性的先验假设。
