PERCEPTUAL CONSTRAINTS FOR IMAGE UNDERSTANDING IN HUMANS

当人们看一个场景时，人们立即能够将边缘分类为 场景，感知到该边缘是阴影边界，该边缘是 表面的折痕等等。如果我们认为视觉系统是 致力于从图像数据中解释场景属性，我们可以说， 视觉系统非常善于确定 边缘在图像中投影到的轮廓。 此外，视觉系统 使用由图像中的轮廓的配置提供的信息， 帮助解释场景属性，如曲面形状。 问题 的等值线解释，其中包括这两个功能，出现 当人们认为图像中提供的信息 这两个函数都是局部模糊的。 解决问题的方法 许多计算机视觉研究人员采用的方法是指定一组 对等高线解释的限制，当这些限制放在一起时， 独特的解决方案。 类似的方法可以用来组织研究， 人类对轮廓的感知处理。 在这一方法中，人们认为 视觉系统隐含地强制执行一组约束， 轮廓的解释。 这些约束来自两个来源：图像数据本身和图像的自然属性。 环境的结构。 本提案旨在分析 这两种类型的约束可能对视觉 系统的轮廓解释和调查心理 视觉系统实际使用的约束的性质。 研究 将集中在两种类型的轮廓，已收到的约束 视觉研究人员相对较少关注：反射轮廓， 其从表面反射的不连续性投射，并且阴影 轮廓，从场景中照明的不连续性投影。 还将考虑遮挡边缘，因为它们在 确定场景结构。 研究的一个重要方面是 使用3D渲染技术生成自然图像， 实验刺激 这将允许操纵独立的 3D场景域和2D图像域中的变量。 的能力 控制场景的3D结构对于研究 视觉系统对边缘结构的自然约束是什么 因为这些是在场景域中而不是在图像域中指定的。 日 调查结果将使人们更深入地了解 图像中可用于等高线解释的信息以及 这些信息被人类视觉系统所使用。 更广泛地说， 这项研究涉及的问题是， 结构和图像形成过程被纳入视觉 系统处理。

When one looks at a scene, one is immediately able to classify the edges in the scene, perceiving that this edge is shadow boundary, that edge is a crease in a surface and so on. If we consider the visual system to be working to interpret scene attributes from image data, we would say that th visual system is very good at determining the physical causes of the contours to which edges project in an image. Moreover, the visual system uses information provided by the configuration of contours in an image to help interpret scene attributes such as the shapes of surfaces. The proble of contour interpretation, which includes both of these functions, appears quite difficult when one considers that the information provided in an imag for both functions is locally ambiguous. The approach to the problem adopted by many computer vision researchers is to specify a set of constraints on contour interpretation which, when taken together, define a unique solution. A similar approach can be used to organize research into human perceptual processing of contours. Within the approach, one consider the visual system as implicitly enforcing a set of constraints in its interpretation of contours. The constraints come from two sources; the image data itself and the natura structure of the environment. The present proposal aims to analyze the constraints of both types which are potentially available to the visual system for contour interpretation and to investigate psychophysically the nature of the constraints actually used by the visual system. The research will focus on constraints on two types of contour which have received relatively little attention from vision researchers: reflectance contours, which project from discontinuities in surface reflectance, and shadow contours, which project from discontinuities in illumination in a scene. Also considered will be occluding edges, due to their importance in determining scene structure. An important aspect of the research will be the use of 3D rendering techniques to generate naturalistic images for experimental stimuli. This will allow the manipulation of independent variables in both the 3D scene domain and the 2D image domain. The ability to control the 3D structure of scenes is necessary for the investigation of what natural constraints on edge structure are assumed by the visual system since these are specified in the scene domain, not in the image domain. Th results of the investigation will provide a deeper understanding of the information available in images for contour interpretation and the ways in which this information is used by the human visual system. More broadly, the research relates to the issue of how much knowledge of environmental structure and of the image formation process is incorporated into visual system processing.