【摘要】 直接在光栅图纸上拾取图元是光栅/矢量混合编辑的核心技术.提出一种能准确拾取图元,并且可以有效保护其他图元矢量信息的拾取算法.首先从图元附近一点开始,经轮廓跟踪、参数拟合得到图元的初始参数;然后在初始参数引导下,对图元定向跟踪,跳过断点和交点,最大限度地拾取整个图元;最后在光栅图纸上删除该图元,并恢复与之相交的其他图元的交点信息.实验证明,该法简便、准确,可迅速修改局部工程图纸.更多还原

【Abstract】 Picking elements directly from raster drawing is the core technology of Raster/Vector mixed editing.A picking element algorithm which can get exact vector parameters and protect vector information of the elements intersecting with the picked element is presented: firstly,getting certain amounts of boundary points by contour tracing from a point near an element and calculating primal parameters; secondly,picking the element completely by element tracing guided by these initial parameters,jumping over broken points and intersecting points;and finally,deleting the picked elements from the raster drawing and renewing other elements′ information intersecting with the picked element.It is tested that the method is simple and accurate for rapidly revising local engineering drawing.更多还原