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，视觉纹理刺激可以用来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“纹理分离的后袋模型”。每个通道由(1)初始线性空间滤波器、(2)非线性和(3)第二线性滤波器组成。这些通道提供(4)组合规则或链接假设，以产生对给定任务中的绩效的响应或预测。我们的工作试图证实这一模型，描述其机制，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标。第一个目标是关于自然纹理的编码和外观。我们调查了人类纹理编码是否与自然纹理的统计相匹配，以及观察者可以在多大程度上独立于观看条件来估计纹理的物理特征。第二个目标是研究后袋模型通道如何用于识别纹理定义的对象，并包括进一步研究后袋模型通道的结构和选择性。第三个目标是研究纹理或二阶通道的皮层实现，使用功能磁共振成像来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.