THE ROLE OF SUPRATHRESHOLD CONTRAST IN VISION

超阈值对比度在视觉中的作用

• 批准号: 3257135
• 负责人: GORDON E LEGGE
• 金额: $ 7.47万
• 依托单位: UNIVERSITY OF MINNESOTA
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-12-01 至 1994-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3257135
• 关键词: cataract; human subject; neural information processing; psychophysics; visual feedback; visual fields; visual perception; visual stimulus; visual threshold

Contrast plays a crucial role in pattern vision. Loss of contrast hampers vision in may ways. This proposal deals with the influence of suprathreshold contrast in human vision. The research has three main purposes: to study the spatial properties of visual mechanisms that code contrast, to use what we have learned about contrast coding to enhance images for people with low vision, and to link work on the sensory coding of contrast to perceptual processes of object recognition. We will use psychophysical and image processing methods in four series of experiments. In the first, we will use a new "yoked-contrast" procedure to distinguish between two models of contrast coding. In the second series, we will use a new variant of the simultaneous detection/identification paradigm to study spatial-frequency and orientational selectivity as a function of contrast. In the third series, we will apply principles of contrast coding to the design of image-enhancement algorithms based on gray-scale histogram flattening. We are particularly interested in the potential value of such techniques for those people with low vision who suffer from attenuated retinal contrast (e.g. cataract) or reduced contrast sensitivity (e.g. central-field loss). In the fourth series, we will use the concept of an "ideal observer" from signal-detection theory to measure how efficiently subjects code and use stimulus information to understanding the difficulties experienced by people with low vision on object recognition.

对比在模式视觉中起着至关重要的作用。 损失对比度 以五月的方式欣赏愿景。 该提案涉及影响 人类视野中的对比度。 这项研究有三个 主要目的：研究视觉的空间特性 代码对比的机制，使用我们学到的知识 对比编码以增强视力低下的人的图像，并且 将与感知形成对比的感觉编码链接起来 对象识别的过程。 我们将使用心理物理和 四个系列实验中的图像处理方法。 在 首先，我们将使用新的“ yoked对比”程序来区分 在两种模型的对比编码之间。 在第二个系列中，我们 将使用同时检测/识别的新变体 研究空间频率和定向选择性的范例 作为对比的函数。 在第三个系列中，我们将申请 编码图像增强设计的对比原理 基于灰度直方图平坦的算法。 我们是 对此类技术的潜在价值特别感兴趣 对于那些视网膜衰减的低视力的人 对比度（例如白内障）或降低对比度灵敏度（例如 中场损失）。 在第四个系列中，我们将使用该概念 从信号检测理论中的“理想观察者”到测量 有效地对代码进行编码并使用刺激信息 了解低点的人遇到的困难 对象识别的愿景。