Visual Perception and Coding of Texture

描述（由申请人提供）：本提案中的实验共有两个基本主题。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，即“纹理分离的后袋模型”联系起来。每个通道由（1）初始线性空间滤波器、（2）非线性滤波器和（3）第二线性滤波器组成。这些通道提供（4）组合规则或关联假设，从而产生给定任务中的响应或性能预测。我们的工作试图确认这个模型，描述其机制，分析其能力，并将其与潜在的生理学联系起来。这项建议有三个主要目的。第一个目标涉及自然纹理的编码和外观。我们调查人类的纹理编码是否与自然纹理的统计数据相匹配，以及观察者在多大程度上可以独立于观看条件来估计纹理的物理特性。第二个目的是研究如何使用后袋模型通道的纹理定义的对象的识别，并包括后袋模型通道的结构和选择性的进一步调查。第三个目的是调查皮质实现纹理或二阶通道使用功能磁共振成像测量响应和适应纹理调制。

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.