生物大分子电子晶体学中的像分析与像处理

Image Analysis and Image Processingin Electron Crystallography for Biological Macromolecules

本文概述了用生物大分子电子晶体学方法测定蛋白质分子结构的计算机数字图像分析与图像处理的若干问题。首先，简介了图像分析的基本数学工具──富里叶变换及其特性。其次，介绍了用富里叶变换法进行像分析的若干问题──衍射空间频率成分的分离、衬度传递函数（ＣＴＮ）的校正以及从投影进行三维重建。第三，介绍了对不同对称性物体──二维晶体、螺旋对称体，二十面体球状病毒颗粒三维重建中的像处理问题以及晶格校正和相关平均法。最后，本文还就目前国际流行的生物大分子电子显微镜图像分析的软件系统的情况作了简要的叙述。

In this paper,some problems of the computer digital image analysis and processing have been describedgenerally in the determination of protein molecular structures by using electron Crystallography for biologicalmacromolecules. At first,the Characteristics of the basic mathematical toll,Fourier transformation,have beenbriefly introduced.Secondly,the problems in image analysis of Fourier transformation(including the separationof the compositon of the different spatial frequeney,the correction of the contrast transfer function,the three di-mensional reconstrution from the two dimensional projections)have been introduced.Thirdly,the image pro-cessing problems of the objects with the different symmetries(including two dimensional ctystals,helices,sim-ple particles of icosahedral globular viruses)in the three dimensional reconstruction. At last,there is a brief de-scription of current software systems for the electron microscopic images analysis of the biological macro-molecules.