对联机手写汉字识别技术的研究——实现笔画识别

联机手写汉字识别(OLCCR)，是指用笔在图形输入板上写字，人一边写，机器一边认，是一种方便的汉字识别手段。在各种自动识别输入的方法中，OLCCR是能够代替或部分代替人工编码输入的惟一可能的方法。识别中主要是两方面的问题：建立汉字识别库和手写板上笔画轨迹的识别。文中就第二方面即手写笔画识别的问题进行了全面的研究，采用笔画基元帮助分析笔画轨迹，并用可视化编程工具Visual C 6.0实现了基于这种方法的笔画识别过程。     

基于手写体汉字笔画提取重构的识别方法

提出了手写体汉字笔画宽度提取、基于提取出的笔画宽度归一化手写体汉字的方法，给出手写体汉字笔画重构的思想，实现了一种基于手写体汉字笔画提取的汉字重构并最终识别手写体汉字的算法，构建了手写体汉字的识别系统。实验证实，该方法可保证原有笔画特征信息，且能有效地识别手写体汉字。     

Off-line handwritten Korean character recognition based on stroke extraction and representation

In this paper, we propose an off-line recognition method for handwritten Korean characters based on stroke extraction and representation. To recognize handwritten Korean characters, it is required to extract strokes and stroke sequence to describe an input of two-dimensional character as one-dimensional representation. We define 28 primitive strokes to represent characters and introduce 300 stroke separation rules to extract proper strokes from Korean characters. To find a stroke sequence, we use stroke code and stroke relationship between consecutive strokes. The input characters are recognized by using character recognition trees. The proposed method has been tested for the most frequently used 1000 characters by 400 different writers and showed recognition rate of 94.3%.     

基于神经网络和模糊匹配算法的手写汉字预分类研究

对手写汉字识别问题,提出了一种在识别之前对手写汉字预分类的新方法,该方法用Neocognitron网提取字符笔画特征,然后采用有监督的扩展ART神经网络（SEART）产生一定数量的预分类组并通过基于模糊相似测量的匹配算法进行预分类。实验表明,该方法用于手写汉字分类效果良好,预分类正确率达到98.22％。     

一种脱机手写体汉字识别的容错编码方法研究

手写体汉字识别是字符识别领域中的难点。为了使机器识别汉字适应于手写体汉字的变形等因素,基于人类认识汉字的容错机理,提出了一种用于机器识字的汉字容错编码方法,以提高手写体汉字识别率。该编码方法首先对横竖撇捺笔划形态给出了模糊化表示;然后定义了仿人拆字的字元集,并给出了易混淆笔划字元的多归类容错编码;接着给出了笔划字元的顺序判断规则和归结了36类简单常用字的部首子结构,并给出冗余的容错编码;进而建立了仿人构字的汉字编码规则和具有容错性的多模板字典,并对《新华字典》中收录的10000余个单字汉字进行了标准编码,重码率为0.48%;最后对HCCORG和NKIM手写体汉字库中的100个手写体汉字进行了仿真识别,识别正确率为96%。试验结果表明,这种编码方法可生成多模板字典,不仅对手写体汉字变形具有较好的容错性,且重码率和误识率较低。     

Preprocessing for Chinese character recognition and global classification of handwritten Chinese characters

Techniques for calculating the stroke directions of thinned binary characters and for detecting the intersections and end points of strokes by means of pattern matching and weighting method are proposed as a preprocessing of handwritten Chinese character recognition. We also propose a method for global classification of handwritten Chinese characters by means of projection profiles of strokes and show that the method is available for the Chinese characters written in the square style.     

一种改进的脱机手写汉字四角特征粗分类方法

将粗分类应用于脱机手写汉字识别中,采用这种多层次分类策略,能有效地改善识别的性能,提高识别精度。本文提出了一种利用四角区域结构特征对手写汉字进行粗分类的方法。在对汉字基本笔画进行分析的基础之上,根据手写汉字形变的特点以及识别算法的要求,定义一组新的笔画单元,并将这些笔画单元与汉字特定区域内的结构进行比对,得到一组4位结构特征编码,以此作为脱机手写汉字粗分类的依据。对GB2312一级字库中的部分手写汉字进行采样和识别实验,结果证明改进的四角结构特征用于粗分类的有效性。     

Model-based stroke extraction and matching for handwritten Chinese character recognition

This paper proposes a model-based structural matching method for handwritten Chinese character recognition (HCCR). This method is able to obtain reliable stroke correspondence and enable structural interpretation. In the model base, the reference character of each category is described in an attributed relational graph (ARG). The input character is described with feature points and line segments. The strokes and inter-stroke relations of input character are not determined until being matched with a reference character. The structural matching is accomplished in two stages: candidate stroke extraction and consistent matching. All candidate input strokes to match the reference strokes are extracted by line following and then the consistent matching is achieved by heuristic search. Some structural post-processing operations are applied to improve the stroke correspondence. Recognition experiments were implemented on an image database collected in KAIST, and promising results have been achieved.     

基于笔划宽度提取的手写体汉字归一化方法

手写体汉字书写变形是手写体汉字识别预处理阶段的重要问题之一。为了有效地改善手写体汉字变形并识别手写体汉字,提出了手写体汉字笔划宽度提取,以及基于提取出的笔划宽度的手写体汉字归一化的方法。用上述方法在计算机上进行仿真实验,实验结果表明,手写体汉字归一化的方法既能保证原手写体汉字的形状结构特征不变,并可有效地改善手写体汉字变形差异。     

基于实时样本采集的个性化手写汉字输入系统设计

手写汉字识别是手写汉字输入的基础。目前智能设备中的手写汉字输入法无法根据用户的汉字书写习惯,动态调整识别模型以提升手写汉字的正确识别率。通过对最新深度学习算法及训练模型的研究,提出了一种基于用户手写汉字样本实时采集的个性化手写汉字输入系统的设计方法。该方法将采集用户的手写汉字作为增量样本,通过对服务器端训练生成的手写汉字识别模型的再次训练,使识别模型能够更好地适应该用户的书写习惯,提升手写汉字输入系统的识别率。最后,在该理论方法的基础上,结合新设计的深度残差网络,进行了手写汉字识别的对比实验。实验结果显示,通过引入实时采集样本的再次训练,手写汉字识别模型的识别率有较大幅度的提升,能够更有效的满足用户在智能设备端对手写汉字输入系统的使用需求。     

Handwritten Chinese Character Recognition Based on Primitive and Fuzzy Features via the SEART Neural Net Model

A handwritten Chinese character recognition method based on primitive and compound fuzzy features using the SEART neural network model is proposed. The primitive features are extracted in local and global view. Since handwritten Chinese characters vary a great deal, the fuzzy concept is used to extract the compound features in structural view. We combine the two categories of features and use a fast classifier, called the Supervised Extended ART (SEART) neural network model, to recognize handwritten Chinese characters. The SEART classifier has excellent performance, is fast, and has good generalization and exception handling abilities in complex problems. Using the fuzzy set theory in feature extraction and the neural network model as a classifier is helpful for reducing distortions, noise and variations. In spite of the poor thinning, a 90.24% recognition rate on average for the 605 test character categories was obtained. The database used is CCL/HCCR3 (provided by CCL, ITRI, Taiwan). The experiment not only confirms the feasibility of the proposed system, but also suggests that applying the fuzzy set theory and neural networks to recognition of handwritten Chinese characters is an efficient and promising approach.     

一种基于SVG的在线连续手写汉字多步分割方法*

基于可伸缩矢量图SVG的在线手写汉字是以SVG图像作为汉字图像格式、以SVG的path对象作为笔画的基本存储单元来对汉字进行显示和存储的,笔画的轮廓是以手写过程中记录的坐标值作为特征数值加以确定的。基于此种SVG手写汉字存储和表示形式,本文提出一种基于图论的在线连续手写汉字多步分割方法。该方法根据汉字笔画间的坐标位置关系对手写笔画序列构建无向图模型,并利用图的广度优先搜索将原笔画序列分割为互不连通的笔画部件,使偏旁部首分离较远、非粘连汉字得到正确分割;然后利用改进的tarjan算法对部件中的粘连字符进行分割,最后基于笔画部件间距,利用二分类迭代算法对间距进行分类,找出全局最佳分割位置,对过分割的部件进行重组合并。实验结果表明,该方法对于在线手写汉字的分割是有效可行的。     

手写体汉字特征分析

本文采用结构方法研究汉字手写体识别。通过对手写体汉字结构特征和书写特点的研究，我们发现，以直划和折划来表征笔划特征，以相交字元和基本字元来表征汉字结构特征，大大降低了结构方法中决策判断串行的程度。     

Fuzzy state machines to recognize totally unconstructed handwritten strokes

An automatic off-line character recognition system for totally unconstrained handwritten strokes is presented. A stroke representation is developed and described using five types of feature. Fuzzy state machines are defined to work as recognizers of strokes. An algorithm to obtain a deterministic fuzzy state machine from a stroke representation, that is capable of recognizing that stroke and its variants is presented. An algorithm is developed to merge two fuzzy state machines into one machine. The use of fuzzy machines to recognize strokes is clarified through a recognition algorithm. The learning algorithm is a complex of the previous algorithms. A set of 20 stroke classes was used in the learning and recognition stages. The system was trained on 5890 unnormalized strokes written by five writers. The learning stage produced a fuzzy state machine of 2705 states and 8640 arcs. A total of 6865 unnormalized strokes, written freely by five writers other than the writers of the learning stage, was used in testing. The recognition, rejection and error rates were 94.8%, 1.2% and 4.0%, respectively. The system can be more developed to deal with cursive handwriting.     

A novel stroke-based feature extraction for handwritten Chinese character recognition

A stroke-based approach to extract skeletons and structural features for handwritten Chinese character recognition is proposed. We first determine stroke directions based on the directional run-length information of binary character patterns. According to the stroke directions and their adjacent relationships, we split strokes into stroke and fork segments, and then extract the skeletons of the stroke segments called skeleton segments. After all skeleton segments are extracted, fork segments are processed to find the fork points and fork degrees. Skeleton segments that touch a fork segment are connected at the fork point, and all connected skeleton segments form the character skeleton. According to the extracted skeletons and fork points, we can extract primitive strokes and stroke direction maps for recognition. A simple classifier based on the stroke direction map is presented to recognize regular and rotated characters to verify the ability of the proposed feature extraction for handwritten Chinese character recognition. Several experiments are carried out, and the experimental results show that the proposed approach can easily and effectively extract skeletons and structural features, and works well for handwritten Chinese character recognition.     

基于模糊规则和相似测量的手写汉字预分类法

文章提出了一种手写汉字预分类的新方法,该方法分两步进行,首先提取笔划密度特征并用模糊规则产生四个预分类组;然后通过模糊逻辑处理将各组字符分别转换成基于非线性加权函数的模糊样板并通过基于模糊相似测量的匹配算法、相似性测量样板的分级分类进行预分类。测试结果表明,该方法效果良好,预分类正确率达到98.17%。     

Recognition of handwritten cursive Arabic characters

An automatic off-line character recognition system for handwritten cursive Arabic characters is presented. A robust noise-independent algorithm is developed that yields skeletons that reflect the structural relationships of the character components. The character skeleton is converted to a tree structure suitable for recognition. A set of fuzzy constrained character graph models (FCCGM's), which tolerate large variability in writing, is designed. These models are graphs, with fuzzily labeled arcs used as prototypes for the characters. A set of rules is applied in sequence to match a character tree to an FCCGM. Arabic handwritings of four writers were used in the learning and testing stages. The system proved to be powerful in tolerance to variable writing, speed, and recognition rate     

Eigen-deformations for elastic matching based handwritten character recognition

Deformations in handwritten characters have category-dependent tendencies. In this paper, the estimation and the utilization of such tendencies called eigen-deformations are investigated for the better performance of elastic matching based handwritten character recognition. The eigen-deformations are estimated by the principal component analysis of actual deformations automatically collected by the elastic matching. From experimental results it was shown that typical deformations of each category can be extracted as the eigen-deformations. It was also shown that the recognition performance can be improved significantly by using the eigen-deformations for the detection of overfitting, which is the main cause of the misrecognition in the elastic matching based recognition methods.     

基于高阶统计的手写字符形变弹性匹配法

针对传统弹性匹配法在手写字符识别中存在着由于过匹配而造成误识别的不足,提出一种基于高阶统计的形变弹性匹配法。根据高阶统计量包含字符形状上的细节变化信息,采用独立分量分析抽取出每个字符类的内在变化方向,并将其应用到弹性匹配的形变模型中。字符的任意种形状变化由这组独立分量的线性叠加来表示。通过形变模型,类模板字符发生形变逐次向输入待识别字符趋近,从而在两个字符之间求得一种最佳匹配。在实验结果中,识别率达到92.81%,得到了提高,表明该方法的有效性。