图纸图像上线条的交互拾取

PICKING LINES INTERACTIVELY FROM DRAWING IMAGE

目前图纸的处理技术可以分为两类：矢量化处理和图像级处理．两者都存在各自很难解决的问题：矢量化的准确度不高，图像级的交互操作又不方便．本文提出的在图纸图像上直接拾取直线的思想来源于两者的有机结合，极大地方便了图像级的交互操作．它的基本思想是：从直线上一点开始，连续扫描跟踪直线的走向，在跟踪的过程中，不断用抽样点校正直线方程；在直线与其它图元的交叉点处，删除该线后进行专门的交叉点恢复，以使其它图元的点阵信息不因该直线的拾取删除而被破坏．

There are two kinds of methods known now for drawing process:vectorization and image level process. They prospectively face some special difficult problems: the accuracy of vectorization is low and the conveniency of interactive operation on raster image is bad. This paper presents an idea about picking lines directlyfrom drawing image, which comes from the combination of the two previous methods, and will greatly improve the conveniency of operation at image level. The algorithm successively scans and traces a line from a start point on the line. Duringtracing, the equation of the line is justified with sample points. At the interactionpoint, a special process is needed to recover the pixel information after deleting theline, so as to ensure other primitives not be destroyed here.