摘要
通过二维输入设备采样获得的手绘形状数据为离散的点,这些数据只有当被以某种数学形式表示时有更多的实际意义,Spline即是一种常用的表示形式。本文对手绘形状数据进行了参数化,在此基础上进行了Spline拟合。然而将一个手绘形状中的全部点序列进行Spline拟合时会使尖状角点被平滑,因而使手绘形状的这一重要特征发生了偏离。为此,本文对一次拟合的Spline进行曲率计算,求取曲率的极大值,并将极大值作为角点将采样点进行分段,然后对分段后的采样点进行二次Spline拟合。实验结果表明,这种方法在获得平滑效果较好的手绘形状的同时,保留了重要的角点特征。
Freehand shapes acquired from a 2D input device are represented in discrete coordinates. These data make more sense when they are represented in some mathematical forms, for which Spline is a due candidate. This paper parameterizes the original freehand shape data first, and then fit them using Spline. However, we have found that whole shape Spline fitting smoothes comer points toward circles, diminishing comers which are significant shape features. To remedy this drawback, we calculate curvature along this first pass Spline, search for the local maximums which represent comers, divide the shape data into segments by these comers, and finally fit each segment with Spline. Experimental results show that the proposed approach well retains shape comers and while smoothes segments between these comers.
出处
《信息技术与信息化》
2008年第3期44-45,48,共3页
Information Technology and Informatization
