Abstract: In this paper，the structure of autostereoscopic display and the principles of its 3D vision are presented，the principles of image modification methods of autostereoscopic based on the D3D technology is also studied，Based on this，the pixel-mask method is further studied.The paper also introduces the operating formula of different observing angle and position in the nine-tile’s.Based on the analyse of the advantage and disadvantage，improved algorithm is presented.The image compose methods is also improved.Finally，experiments are presented to compare the primitive method，pixel mask method and improved pixel mask method in the prepare time before image display，the render time of one frame and the feeling of the 3D.

Key words: autostereoscopic, pixel mask, true 3D, nine-tile

摘要： 介绍了自动立体镜显示器的结构及其三维显示的原理，研究了基于D3D技术的自动立体镜三维图像生成原理，对点蒙板方法做了深入的研究，给出了九片图中观察角度、位置以及视点观察空间的变换运算公式，在分析其优缺点的基础上提出了改进算法。并对最终图像的合成算法作了改进。在自动立体镜显示器上分别用原始方法、点蒙板方法、以及改进的点蒙板方法对图像进行显示，并在显示前准备时间、一帧图像渲染时间、三维深度感觉三方面对三者进行了对比实验。

关键词: 自动立体镜, 点蒙板, 真三维, 九片图