Surface color perception and illuminant cues in dynamic three-dimensional scenes

人类视觉最令人印象深刻的方面之一是在非常不同的照明条件下表面颜色的稳定性。视觉系统非常擅长将照明的颜色与表面的实际颜色区分开来，工程师们目前还无法制造出能与人类表现相媲美的相机。大多数先前的研究都集中在非常简单的刺激上，包括在漫射（均匀）照明下的平板上排列的少量平面彩色表面。这项提议的研究利用计算机图形学的最新进展来创建物理精确的虚拟场景，其中充满了许多不同深度和方向的物体，这些物体由逼真的日光光源照亮，模拟太阳、天空和云层的效果。在这样的场景中，视觉系统面临的主要挑战是光照很少均匀。在这里提出的研究中，研究者将分析视觉系统如何使用关于照明条件的简单“线索”，如表面阴影和高光，来估计稳定的表面颜色。眼动追踪技术的使用允许实验者在收集有关场景照明条件的信息时监视观察者的目光。该研究首次使用眼动追踪技术来研究表面颜色感知。人类赋予物体稳定的表面颜色和形状的能力是一项非凡的成就。这项研究将使我们更好地了解大脑如何自适应地利用场景中深度和颜色的信息来源，从而更好地了解大脑对损伤、疾病甚至正常衰老的反应。此外，关于大脑如何使用场景布局和照明的线索的研究可以为复制生物功能的人工视觉系统的生产提供信息。植物和动物的许多疾病状态都伴随着表面颜色的细微变化，这种系统将在遥感方面有明显的应用，从监测作物到早期发现疾病。

One of the most impressive aspects of human vision is the stability of surface colors under very different lighting conditions. The visual system is remarkably good at separating the color of the illumination from the actual colors of surfaces and engineers are not currently able to build a camera that can match human performance. Most previous research has focused on very simple stimuli consisting of a small number of flat colored surfaces arranged on a flat panel under diffuse (uniform) lighting. The proposed research makes use of recent advances in computer graphics to create physically-accurate virtual scenes filled with objects at many different depths and orientations illuminated by realistic daylight illuminants mimicking the effects of sun, sky and cloud cover. The major challenge for the visual system in such scenes is that illumination is rarely uniform. In the research proposed here, the investigator will analyze how the visual system uses simple "cues" about illumination conditions such as surface shading and highlights to estimate stable surface colors. The use of eye tracking technology allows the experimenter to monitor where the observer looks in gathering information about the conditions of scene illumination. The proposed research represents the first use of eye-tracking technology to study surface color perception.The human ability to assign stable surface colors and stable shapes to objects is an extraordinary achievement. This research will lead to a better understanding of how the brain adaptively makes use of sources of information about depth and color in scenes which, in turn, will provide a better understanding of how the brain reacts to injury, disease and even normal aging. Moreover, research on how the brain uses cues to scene layout and lighting can inform the production of artificial visual systems that duplicate biological function. Subtle changes in surface color accompany many disease states in plant and animal and such systems would have evident applications in remote sensing, from monitoring crops to early detection of illness.