局部关联度最优的手写汉字骨架提取  

Skeleton extraction algorithm based on optimum local correlation degree for handwritten Chinese characters

作　　者：周正扬[1,2] 詹恩奇[1] 郑建彬[1] 胡华成[1] 

机构地区：[1]武汉理工大学信息工程学院,武汉430070 [2]光纤传感技术与信息处理教育部重点实验室(武汉理工大学),武汉430070

出　　处：《中国图象图形学报》2017年第6期833-841,共9页Journal of Image and Graphics

基　　金：国家自然科学基金项目(61303028)~~

摘　　要：目的研究手写汉字图像时,骨架是最为常见的切入点之一。利用传统细化算法提取手写汉字骨架,容易在笔画交叉等情况复杂的区域产生形变。针对此问题,提出一种基于局部关联度的手写汉字骨架提取算法。方法首先对手写汉字图像进行细化以获取原始骨架,按照端点、普通点和复杂点3种类别标注骨架点;利用8邻域窗口扫描相互连通的复杂点,检测并提取复杂区域;删除复杂区域,将原始骨架拆分为若干简单笔画段,形变部分在此过程中被一并移除;提取局部子段,根据笔画段间的方向差异程度和曲率变化程度,计算局部关联度;制定一种局部关联度最优的连接策略,对满足连接条件的笔画段进行插值补偿,从而修正形变,并得到完整的汉字骨架。结果对于600个实验样本,从骨架直接检测复杂区域所得结果十分接近理想情况,而轮廓法所得数量是理论值的2.5倍;基于局部关联度重组笔画段,绝大多数形变得到修正,重组后的骨架符合真实拓扑结构;以标准骨架为参考,骨架提取准确率达到了98.41%。结论局部关联度最优的手写汉字骨架提取算法,能够有效检测复杂区域,对形变具有良好的修正作用,提取所得骨架能够正确反映复杂笔画间的位置结构关系,是一种实用有效的骨架提取方法。Objective Studies on handwritten Chinese characters, such as those on signature verification and text recogni- tion, have been conducted for many years. The skeleton is a key po!nt in these studies. It reduces redundant information but retains a complete topology structure. Using a thinning algorithm to extract a skeleton from a handwritten Chinese char- acter image is a traditional approach. However, distortions exist in the extracted skeleton primarily because the complex ar- eas are not well detected nor processed. Complex areas are the intersections and junctions of strokes. Considering that char- acters are saved as static images, a computer cannot recognize the existence of these areas with more than one stroke. The computer still regards these areas as an entirety, so the thinning algorithm does not perform well. To solve distortion, this study proposes a skeleton extraction algorithm based on the optimum local correlation degree for handwritten Chinese charac- ters. Method A simple and effective method to extract complex areas is designed. This method uses a thinning algorithm toobtain the original skeleton. The points on the skeleton are classified as end, common, and complex points. Complex areas are extracted by detecting connected complex points with an eight-neighbor window. Afterward, the information on complex areas is used to modify the original skeleton. The modification algorithm is based on a strategy involving split and recon- struction. The skeleton is split into several stroke segments because all complex areas are removed. Distortions are also eliminated in the removal. The reconstruction step focuses on the reconnection of stroke segments ; it analyzes the relation- ship among stroke segments to restore the skeleton. The directional relationship is considered. The slope between two end points of a segment may not accurately represent the correct direction because the stroke segments are not always straight. Sub-segments adjacent to a complex area can provide the required directional inform

关 键 词：手写汉字 细化 骨架形变 复杂区域 局部关联度 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]