基于影子显示位图技术的GIS图形部分的实现

在地理信息系统的开发过程中，对屏幕图形进行精确识别是一个较难解决的技术问题．在某些实际应用中，近似处理的误差已经超过了人们所能接受的程度．该文就地理信息系统中的图形识别技术提出了一种全新的方法——影子显示位图（shadow display bitmap）技术．影子显示位图技术用于精确地识别显示在屏幕上的各种简单的和复杂的图形元素．该文论述了影子显示位图技术的工作原理和实现方法，通过实验证明影子显示位图技术解决了识别图形元素时的误差问题，识别复杂图形元素的能力强，比常用图形识别技术容易实现．

GIS implementation of graph part based on shadow display bitmap technology

In the development of geographic information system, it＇s difficult to recognize screen graph precisely. In some practical applications, the approximate processing error has already exceeded people＇s acceptable degree. A new method-shadow display bitmap technology was proposed based on the graphic recognition technology in geographic information system. The shadow display bitmap technology is used to precisely recognize diversified simple and complicated graph elements displayed on screen. Then the prifibiple and the realization method of the shadow display bitmap technology were discussed. Moreover, it＇s proved through thle experiment that the shadow display bitmap technology, which solved the error problem of graph elements recognition, has strong ability of complicated graph elements recognition. And it＇s easier to be realized than common graphic recognition technology.