一种改进的中文字符矢量化算法  

An Improved Vectorization Algorithm of Chinese Character Bitmap

作　　者：李新杰 江子傲 王存睿 LI Xin-jie;JIANG Zi-ao;WANG Cun-rui(School of Computer Science and Engineering, Dalian Minzu University, Dalian Liaoning 116650, China)

机构地区：[1]大连民族大学计算机科学与工程学院,辽宁大连116605

出　　处：《大连民族大学学报》2021年第3期244-250,共7页Journal of Dalian Minzu University

基　　金：辽宁省自然科学基金项目(2020-MZLH-19);贵州省科技支撑计划项目(2021-534)。

摘　　要：针对人工进行字体的矢量化耗时费力的问题,提出一种改进的Potrace字体图像矢量化方法。基于Potrace位图矢量化算法,首先得到位图路径的初始点集,然后通过夹角判别法和计算删除代价(DC)值来删除冗余点得到最终关键点集,再根据弧弦距判别法判断矢量段的拟合类型,最后使用Bezier曲线插值拟合关键点并优化轮廓路径。为了衡量矢量化后的曲线轮廓的质量,建立了字体曲线轮廓的度量指标体系,其中包括轮廓尖锐度、关键点冗余率、锚点准确度和形状吻合度等指标。实验表明:Potrace算法的冗余率大约在56%左右,而改进后的Potrace算法则将冗余率降到10%左右,并且本方法在锚点选择的准确度方面较Potrace算法有提高,形状吻合度与Potrace算法持平,可以提升字体图像矢量化的效率和质量,同时也能尽可能减小曲线字库的空间存储量。It is time-consuming and laborious to manually vectorize fonts.To solve this problem,an improved Potrace font image vectorization method is proposed.Based on the Potrace bitmap vectorization algorithm,the initial point set of the bitmap path is first obtained,and then redundant points are deleted through the angle discrimination method and the calculation of the deletion cost(DC)value to obtain the final key point set,and then the arc chord distance discrimination method is used to judge the fitting type of the vector segment,and finally Bezier curve interpolation is applied to fit the key points and optimize the contour path.In order to measure the quality of vectorized curve contours,a measurement index system for font curve contours is established,which includes contour sharpness,key point redundancy rate,anchor point accuracy,and shape fit.The experimental results show that the redundancy rate of the Potrace algorithm is about 56%,while the improved Potrace algorithm reduces the redundancy rate to about 10%,and the accuracy of the anchor point selection of this method is higher than that of the Potrace algorithm.The degree of fit is the same as the Potrace algorithm.Using this method,we can greatly improve the efficiency and quality of vectorization of font images,and reduce the space storage of the curve font library as much as possible at the same time.

关 键 词：曲线轮廓 矢量字体 Potrace算法 去除冗余点 贝塞尔曲线 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]