Andersen G J
Department of Psychology, University of Illinois, Champaign 61820.
J Exp Psychol Hum Percept Perform. 1989 May;15(2):363-71. doi: 10.1037//0096-1523.15.2.363.
A common assumption in several analyses of optic flow is that the velocity field must be locally smooth in order to recover relative depth and the structure of surfaces in the environment. This study investigated the appropriateness of this constraint to human perception. In the first experiment, subjects were asked to identify the number of planes present in a display simulating one, two, three, four, or five overlapping, transparent planes. Subjects were able to detect the presence of up to three planes accurately for both horizontal and depth translations. In the second experiment, subjects' judgments of the depth separation of two transparent, overlapping planes increased with the simulated separation. In Experiment 3, subjects were able to determine accurately the sign of depth for two overlapping, transparent surfaces. These results suggest that a smoothness constraint is not required for the analysis of optic flow by human observers. Alternative approaches to the analysis of optic flow are discussed.
在对视流的几种分析中，一个常见的假设是速度场必须在局部是平滑的，以便恢复相对深度和环境中表面的结构。本研究调查了这一约束对人类感知的适用性。在第一个实验中，要求受试者识别模拟一个、两个、三个、四个或五个重叠透明平面的显示器中存在的平面数量。对于水平平移和深度平移，受试者都能够准确检测到多达三个平面的存在。在第二个实验中，受试者对两个透明重叠平面深度分离的判断随着模拟分离而增加。在实验3中，受试者能够准确确定两个重叠透明表面的深度符号。这些结果表明，人类观察者对视流进行分析时不需要平滑性约束。文中还讨论了对视流进行分析的替代方法。
