Visual Perception and Coding of Texture

描述（由申请人提供）：本提案中的实验有两个基本主题。首先，视觉纹理刺激可用于探测图像和图像序列的初始视觉编码。第二个主题是将我们所有的工作与一个基本的4阶段多通道模型联系起来，即“纹理分离的后口袋模型”。每个通道由(1)初始线性空间滤波器，(2)非线性滤波器和(3)第二个线性滤波器组成。这些通道提供(4)一个组合规则或连接假设，产生对给定任务的响应或预测。我们的工作试图证实这一模型，表征其机制，分析其能力，并将其与潜在的生理学联系起来。这项提议有三个主要目的。第一个目标涉及自然纹理的编码和外观。我们研究了人类纹理编码是否与自然纹理的统计相匹配，以及观察者可以独立于观看条件估计纹理物理特征的程度。第二个目标是研究如何使用后口袋模型通道来识别纹理定义的物体，并进一步研究后口袋模型通道的结构和选择性。第三个目的是利用功能磁共振成像（fMRI）来研究皮层对纹理或二阶通道的实现，以测量对纹理调制的反应和适应。

DESCRIPTION (provided by applicant): The experiments in this proposal share two basic themes. The first is that visual texture stimuli may be used to probe the initial visual coding of images and image sequences. The second theme is to relate all of our work to a basic 4-stage, multiple channel model, the "back-pocket model of texture segregation." Each channel consists of (1) an initial linear spatial filter, (2) a nonlinearity, and (3) a second linear filter. These channels feed (4) a combination rule or linking hypothesis that yields a response or prediction of performance in a given task. Our work attempts to confirm this model, characterize its mechanisms, analyze its capabilities, and relate it to the underlying physiology. This proposal has three major aims. The first aim concerns the coding and appearance of natural textures. We investigate whether human texture coding is matched to the statistics of natural textures and the degree to which observers can estimate physical characteristics of textures independent of viewing conditions. The second aim investigates how the back-pocket model channels are used for the identification of texture defined objects and includes further investigations of the structure and selectivity of back-pocket model channels. The third aim is to investigate the cortical implementation of texture or 2nd-order channels using fMRI to measure responses to and adaptation to texture modulations.