Conveying 3D shape with texture: recent advances and experimental findings
Conveying 3D shape with texture: recent advances and experimental findings
复制标题
用纹理传达 3D 形状：最新进展和实验结果
DOI：
10.1117/12.469515
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发表时间：
2002
影响因子：
2.5
通讯作者：
Haleh Hagh
中科院分区：
文献类型：
--
作者：
V. Interrante;Sunghee Kim;Haleh Hagh
如果我们可以设计出适用于任何光滑表面的完美纹理图案，以便使观察者能够在标准照明条件下从任意通用视点拍摄的静态单目图像中更准确地感知表面的形状，那么该纹理图案的特征是什么？为了深入了解这个问题，我们的团队开发了一种高效的算法，用于在任意双曲面上合成高分辨率纹理图案，该图案来自所提供的2D样本，其方式是将纹理的方向约束为在每个像素的水平上跟随曲面上指定的基本矢量场，而没有接缝或投影失真伪影的证据。在本文中，我们报道了最近的一项实验结果，我们试图使用这种新的纹理合成方法来评估两种不同类型的方向纹理模式(单向和双向)在三种不同取向条件下(跟随第一主方向、跟随恒定的均匀方向或在表面上正弦旋转)的形状信息承载能力。在四种选择的强迫选择任务中，我们要求参与者识别从不同的随机方向照射并同时持续显示的两个B-样条面形状不同的象限。我们发现，在所有受试者都在任务中得到了充分的训练后，准确率随着表面形状差异的增加而相当一致地增加，但这种增加的特征在不同的纹理取向条件下是不同的。无论表面形状特征如何，当表面用方向沿着一个主要方向的图案进行纹理处理时，受试者能够更可靠地感觉到较小的形状差异。这些发现似乎支持了我们的假设，即与以任何其他方式定向纹理图案相比，与以其他方式定向的纹理图案相比，通过使观察者明确地获得关于表面曲率范围的更多、可靠的信息，与第一主方向对齐的各向异性纹理可以促进一般视图的形状感知。
If we could design the perfect texture pattern to apply to any smooth surface in order to enable observers to more accurately perceive the surface's shape in a static monocular image taken from an arbitrary generic viewpoint under standard lighting conditions, what would the characteristics of that texture pattern be? In order to gain insight into this question, our group has developed an efficient algorithm for synthesizing a high resolution texture pattern, derived from a provided 2D sample, over an arbitrary doubly curved surface in such a way that the orientation of the texture is constrained to follow a specified underlying vector field over the surface, at a per-pixel level, without evidence of seams or projective distortion artifacts. In this paper, we report the findings of a recent experiment in which we attempt to use this new texture synthesis method to assess the shape information carrying capacity of two different types of directional texture patterns (unidirectional and bi-directional) under three different orientation conditions (following the first principal direction, following a constant uniform direction, or swirling sinusoidally in the surface). In a four alternative forced choice task, we asked participants to identify the quadrant in which two B-spline surfaces, illuminated from different random directions and simultaneously and persistently displayed, differed in their shapes. We found, after all subjects had gained sufficient training in the task, that accuracy increased fairly consistently with increasing magnitude of surface shape disparity, but that the characteristics of this increase differed under the different texture orientation conditions. Subjects were able to more reliably perceive smaller shape differences when the surfaces were textured with a pattern whose orientation followed one of the principal directions than when the surfaces were textured with a pattern that either gradually swirled in the surface or followed a constant uniform direction in the tangent plane regardless of the surface shape characteristics. These findings appear to support our hypothesis that anisotropic textures aligned with the first principal direction may facilitate shape perception, for a generic view, by making more, reliable information about the extent of the surface curvature explicitly available to the observer than would be available if the texture pattern were oriented in any other way.