Ben-Shahar Ohad, Zucker Steven W
Interdepartmental Neuroscience Program, Department of Computer Science, Yale University, New Haven, CT 06520, USA.
Vision Res. 2004 Feb;44(3):257-77. doi: 10.1016/j.visres.2003.08.018.
Texture segregation has long been attributed to changes in the distribution of elementary features across the visual field [Nature 290 (12) (1981) 91; Biol. Cybernet. 54 (1986) 245]. The study of orientation, a conspicuous feature, has led to models of orientation-based texture segmentation (OBTS) that depend on the magnitude of one or two orientation gradients [Vis. Res. 31 (4) (1991) 679; Vis. Res. 31 (6) (1991) 1073] and influenced further by the relative configuration between the orientation textons and the global orientation edge [Percept. Psychophys. 52 (4) (1992) 255; Vis. Res. 35 (20) (1995) 2863]. Here we show that these models are at best partial and that the notion of orientation gradient has been incompletely used in the study of OBTS. To do so, we first study the behavior of orientation in orientation-defined texture patches. Geometrical analysis identifies two texture curvatures and reveals the incompleteness of previous stimuli. Psychophysical experimentation then demonstrates that segmentation is strongly affected by discontinuities in these curvatures. Importantly, we show that this sensitivity to curvature is independent of the orientation gradients and inconsistent with the simple configural considerations proposed in the past.
长期以来，纹理分离一直被归因于基本特征在视野中的分布变化[《自然》290 (12) (1981) 91；《生物控制论》54 (1986) 245]。对显著特征方向的研究，已经产生了基于方向的纹理分割（OBTS）模型，这些模型依赖于一个或两个方向梯度的大小[《视觉研究》31 (4) (1991) 679；《视觉研究》31 (6) (1991) 1073]，并且进一步受到方向纹理子与全局方向边缘之间相对配置的影响[《感知与心理物理学》52 (4) (1992) 255；《视觉研究》35 (20) (1995) 2863]。在这里，我们表明这些模型充其量只是部分正确的，并且方向梯度的概念在OBTS研究中并未得到充分利用。为此，我们首先研究在方向定义的纹理块中方向的行为。几何分析确定了两种纹理曲率，并揭示了先前刺激的不完整性。然后，心理物理学实验表明，分割受到这些曲率不连续性的强烈影响。重要的是，我们表明这种对曲率的敏感性与方向梯度无关，并且与过去提出的简单配置考虑不一致。
