PROCESSING OF LUMINANCE GRADIENTS FOR DETERMINING SURFACE LIGHTTNESS

处理亮度梯度以确定表面亮度

• 批准号: 6271673
• 负责人: ALAN L GILCHRIST
• 金额: $ 3.8万
• 依托单位: RUTGERS THE STATE UNIV OF NJ NEWARK
• 依托单位国家: 美国
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-07-01 至 1999-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6271673
• 关键词: behavioral /social science research tag; 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.

这项研究属于破译程序的广泛努力范围内，通过 人类视觉系统处理视网膜图像中的光模式 为了确定表面的白色、灰色和黑色级别 视野。人们普遍认为感知到的表面灰度级 基于从强度梯度中提取的相对光强度 在视网膜图像中，但对这些相对分子如何 强度是固定的，也就是说，处理以产生特定的阴影 我们所看到的灰色。例如，在许多场景中，视觉系统 自动将最高强度视为白色。这可以是 在最简单的条件下演示，将观察者的头部 在一个巨大的圆顶内，一半的内部被漆成黑色和 其中一半是灰色的。灰色部分将显示为白色，并且 黑色部分将显示为灰色，与亮度最高的白色一致 规则。但如果一个观察者的头被放在统一涂成黑色的 中央有一个白色圆盘的圆顶，黑色圆顶显示为白色 圆盘看起来是发亮的。这表明了一条规则，即白色是 被分配到周围区域，而不是最高强度。人类 观察者将被放置在各种可视环境中，选择 区分不同的潜在锚定规则。这些将包括简单的 完全包围观众的大型塑料穹顶上的图案，更多 复杂的实验室展示、计算机模拟展示和现场自然展示 场景。显示器中每个表面感知的灰色阴影将是 通过让天真的观察者使用灰度进行匹配而获得的。这些 我们将分析这些值，以确定它们代表什么规则。分析 当视野变得越来越大时，锚定规则如何改变 复合体有望填补表面建模方面的一个重要空白 对颜色的感知。了解视觉系统如何决定 表面颜色通常将提供一个基本的框架 了解某些形式的视力损害提供了必要的 了解某些形式的视力损害的框架。