摘要
在线手绘图识别是2D草图重建3D模型领域的关键课题。提出一种基于二次曲线的在线手绘图识别方法和针对复合线元的分割算法,最小的识别单元包括:直线段、折线段、椭圆、椭圆弧、圆、圆弧、双曲线和抛物线。该识别方法利用几何特征对笔划进行自适应分类;采用最小中值二乘法进行二次曲线拟合,确定笔划的具体类型。实验证明,该识别和分割方法能获得令人满意的识别效果,为从2D草图重建3D模型奠定了基础。
Online freehand sketching is an effective way for expressing, communicating and recording ideas during conceptual design. This paper presents a novel method for recognizing online freehand sketching; to assist designers during conceptual design, it develops a human-computer interface prototype system FSR, which makes system interface easy and friendly to user. The system is designed to infer designers＇ intentions and interpret input sketches into more exact 2D geometric primitives, straight line, polyline, circle, circular arc, ellipse, elliptical arc, hyperbola and parabola. Strokes are divided into single primitive and composite primitive, depending on whether they need to be segmented or not. The single primitive is classified as fold line curve and non-fold line curve in accordance with computer＇s order of recognition. Which type of primitive the stroke belongs to is decided by an adaptive algorithm. The use of the least median squares （LMS） method fits the non-fold curve for interpreting whether it is a freehand conic section. If it is not single primitive, then composite primitive segmentation method is used. The FRS system has been tested with a number of freehand sketches and the test results are given in Figs. 4 through 6. The test results show that the algorithm achieves the recognition rate of 96% and 92% for single primitive and composite primitive respectively.
出处
《西北工业大学学报》
EI
CAS
CSCD
北大核心
2007年第1期37-41,共5页
Journal of Northwestern Polytechnical University
基金
陕西省自然科学基金(2002E224)资助
关键词
在线手绘图
识别率
二次曲线
最小中值二乘
online freehand sketching, recognition rate, conic section, least median squares （LMS）
