时变图象光流场计算技术是计算机视觉中的重要研究内容，也是当今研究的热点问题。为了使人们对该技术有一个较全面的了解，因而对时变图象光流场计算技术的研究和进展做了较系统的论述，首先分别列举了灰度时变图象和彩色时变图象的光流场计算方法，并对这些方法进行了分类，然后总结了出目前图象光流场计算中存在的几个问题，最后对光流场计算技术的研究发展及其应用前景指出了一些可能的方向。

Optical flow estimation is a low level phase of motion recovery problem. Its output is a 2D projection of the velocity field on the image plane, which is analyzed further to get high level motion descriptions. A number of approaches have been developed for the optical flow estimation. The gradient based approach for the optical flow estimation is one of the importance kinds, it assumes brightness conservation under motion. This provides one constraint for the two unknown local components of the velocity vector. It is ill determined system of equation. A color image has some significant advantages over black and white image: it can give more optical information. Therefore, the colors images may be improve the solution of the optical flow estimation problem.The paper makes an introductory review on the optical flow estimation including the last achievement in this field. First, give the general concepts and fundamental principles of optical flow. Then, some methods for optical flow estimation are listed, black and white image and color image. Finally, make a discussion on some open problems and point out possible directions for further research.