PROCESSING OF LUMINANCE GRADIENTS FOR DETERMINING SURFACE LIGHTTNESS

处理亮度梯度以确定表面亮度

• 批准号: 5211900
• 负责人: ALAN L GILCHRIST
• 金额: --
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/5211900
• 关键词: brightness discrimination; color visions; computer simulation; human subject; light intensity; neural information processing; psychophysics; vision; vision tests; visual fields; visual perception; visual photoreceptor; visual photosensitivity

This research falls within a broad effort to decode the program by which the human visual system processes the pattern of light in the retinal image in order to determine the white, gray of black level of surfaces within the field of view. It is generally accepted that perceived surface gray levels are based on relative light intensities extracted from intensity gradients in the retinal image, but little is known about how these relative intensities are anchored, that is, processed to yield the specific shades of gray that we see. For instance, in many scenes the visual system automatically treats the highest intensity as white. This can be demonstrated under the simplest conditions by placing an observer's head inside a large dome, half of the interior of which is painted black and half of which is painted gray. The gray part will appear white and the black part will appear gray, consistent with highest-intensity-as-white rule. But if an observer's head is placed within a uniformly painted black dome containing a white disk at its center, the black dome appears white and the disk appears luminous. This indicates a rule by which white is assigned tot eh surrounding region, not to the highest intensity. Human observers will be placed in a variety of visual environments, chosen to distinguish different potential anchoring rules. These will include simple patterns on large plastic domes that completely surround the viewer, more complex lab displays, computer simulated displays, and on-site natural scenes. The perceived shade of gray of each surface in the display will be obtained by having naive observers make matches using a gray scale. These values will be analyzed to determine what rule they represent. Analysis of how the anchoring rules change as the visual field becomes increasingly complex is expected to fill an important gap in the modelling of surface color perception. An understanding of how the visual system determines surface colors in general will provide an essential framework for understanding certain forms of visual impairment provide an essential framework for understanding certain forms of visual impairment.

这项研究福尔斯属于一个广泛的努力，以解码程序， 人类视觉系统处理视网膜图像中的光图案 为了确定在该区域内的表面的白色、灰色或黑色水平， 视野. 人们普遍认为， 基于从强度梯度提取的相对光强度 在视网膜图像中，但很少有人知道这些相对 强度被锚定，也就是说，被处理以产生特定的色调 我们看到的灰色。 例如，在许多场景中，视觉系统 自动将最高强度视为白色。 这可以 在最简单的条件下通过放置观察者的头部来证明 在一个大圆顶内，其内部的一半被漆成黑色， 一半被漆成灰色 灰色部分将显示为白色， 黑色部分将呈现灰色，与最高强度白色一致 统治 但如果观察者的头被放在一个均匀涂成黑色的 圆顶包含一个白色磁盘在其中心，黑色圆顶出现白色 圆盘会发光 这表明了一个规则，白色是 分配给周围区域，而不是最高强度。 人类 观察者将被放置在各种视觉环境中， 区分不同的潜在锚定规则。 其中包括简单的 完全包围观众的大型塑料圆顶上的图案，更多 复杂的实验室显示器、计算机模拟显示器和现场自然 场景 显示器中每个表面的感知灰度将是 通过让天真的观察者使用灰度进行匹配来获得。 这些 值将被分析以确定它们代表什么规则。 分析 锚定规则是如何随着视野变得越来越 复杂的是，预计将填补一个重要的空白，在建模的表面 颜色感知 了解视觉系统如何决定 表面颜色一般将提供一个基本的框架， 了解某些形式的视觉障碍提供了一个必要的 理解某些形式的视觉障碍的框架。