视觉系统初级信息加工的一种数学模型——<Ⅰ>模型的空间性质

本文用广义Gabor(EQ)函数作为视觉系统进行初级信息加工的核函数.所谓广义Gabor函数,就是把原始Gabor函数中的一个独立变量扩展到三个(即空间变量从一维推广到二维,再加时间变量),并相应地引入一些参数.本文中EG取二大类形式:各向同性系统中表达式和各向异性系统表达式.当EG取某一特定形式,而且其中参数取某些特定值时,本模型可分别定性描述电生理实验中发现的几种主要感受野类型(Kuffler,Hubel和Wiesel型等).在空间频率域中引入对数变换假设后,EG经付里叶变换后可很好地合成人眼调制传递函数(MTF)

A MATHEMATICAL MODEL OF PRIMARY INFORMATION PROCESSING IN VERTEBRATE VISUAL SYSTEM

If the vertebrate visual system is considered as linear and homogeneous for image processing in temporal and spatial domains, its kernal function is the key to describing the properties of the system. In this paper, we take the extended Gabor function (EG) as a kernel function for primary information processing of visual system. The so-called extended Gabor function is obtained as the original Gabor elementary signals are extended from one independent variable to three ones (including one variable in time and other two in space),We suggest that EG take two major forms,one is in the isotropic system, the other is in the non-isotropic system.If the parameters in EG function are chosen properly, some main types of receptive field discovered in electrophysiological experiments (for example, Kuffler's and Hubel & Wiesel's receptive fields) can be described by this model qualitatively. Another types of receptive fields can be predicted from this model. If logarithmic transform is introduced in spatial frequency domain, the modulation transfer f unction (MTF) of human vision can be synthesized by taking Fourier transform of the EG functions.