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。     

基于SVM的脱机手写汉字机器学习识别方法研究

提出了一种模糊统计方法的脱机手写体汉字特征提取方法．结合小波网格方法和汉字笔画密度特征方法对汉字进行特征提取，并运用支持向量机方法，通过机器学习对脱机手写汉字识别。仿真实验表明，支持向量机方法在脱机手写汉字识别中有良好的识别性能及模糊统计方法是有效的。     

基于SVM的脱机手写汉字机器学习识别方法研究

提出了一种模糊统计方法的脱机手写体汉字特征提取方法,结合小波网格方法和汉字笔画密度特征方法对汉字进行特征提取,并运用支持向量机方法,通过机器学习对脱机手写汉字识别。仿真实验表明,支持向量机方法在脱机手写汉字识别中有良好的识别性能及模糊统计方法是有效的。     

HMM方法识别脱机手写汉字

本文提出了一种在隐含马尔可夫模型(HMM)框架下建立的识别脱机手写汉字的方法,介绍了以HMM对脱机手写汉字进行建模、识别的整个过程,并给出了实验结果对国标一级3755个汉字的识别率,在两种测试集上分别达到96.4%和91.5%.     

有引导的汉字图像整形变换

在脱机手写汉字识别系统中,采用汉字图像的整形变换,可以提高手写汉字的识别率,特别是对于从网络中提取识别特征的识别方法,其识别率的提高是显著的,本文在研究现有汉字图像整形变换的基础上,提出了对汉字外缘流畅笔划的修整算法,提出了有引导的整形变换的基础上,提出了对汉字外缘流畅笔划的修整算法,提出了有引导的整形变换算法;即在整形变换之前,先对汉字图像的畸变形态及畸变程度进行预测及预处理,以便引导整形变换的     

一种基于笔画密度的弹性网格特征提取方法

本文在分析手写汉字识别的几种非线性归一化方法基础上,提出了五种新的基于笔画密度的弹性网格构造方法,并将之应用到手写汉字的弹性特征提取.该方法既兼顾了笔画密度对不同书写风格笔画不规则变形的适应能力,又避免了进行非线性归一化产生的笔画粗细不均匀,且计算量相对减少.针对1034类别的手写汉字样本的对比实验表明,本文方法的识别率较非线性归一化方法平均增加4.02个百分点,显示了弹性网格较强的适应笔画书写变形的能力.     

基于贝叶斯网络的脱机手写体汉字智能识别

针对汉字识别的超多类问题，将贝叶斯网络分类器引入小样本字符集脱机手写体汉字识别中．对手写大写数字汉字的小样本字符集构造识别系统，同时与传统的欧氏距离方法进行比较，实验表明该算法将识别率提高到92．4％，在小样本字符集脱机手写体识别中具有较强的实用性和良好的扩展性．     

笔顺连笔自由的联机手写汉字识别

论文针对联机手写汉字识别的笔顺自由、连笔自由问题,在整体DP匹配方法的基础上,提出了一种新的确定笔画对应关系的算法(最小风险算法),并同现有的CubeSearch法、匈牙利算法、近邻优先算法在识别速度、识别率等方面作了比较。该方法克服了现有的一些方法的不足,能高效地同时解决笔顺自由和连笔自由问题,而且由于主要采用全局特征进行识别,对形变和噪音具有很强适应能力。另外,字典可以通过聚类自动生成。另外还制作了原型系统,在对GB2312字符集进行的测试中,取得了较好的效果:在笔顺、连笔完全自由的情况下,单汉字平均识别时间小于0.3s,确定笔画对应关系的正确率达99.1%,识别率达94.5%。     

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。     

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。     

Analysis of stroke structures of handwritten Chinese characters

Most handwritten Chinese character recognition systems suffer from the variations in geometrical features for different writing styles. The stroke structures of different styles have proved to be more consistent than geometrical features. In an on-line recognition system, the stroke structure can be obtained according to the sequences of writing via a pen-based input device such as a tablet. But in an off-line recognition system, the input characters are scanned optically and saved as raster images, so the stroke structure information is not available. In this paper, we propose a method to extract strokes from an off-line handwritten Chinese character. We have developed four new techniques: 1) a new thinning algorithm based on Euclidean distance transformation and gradient oriented tracing, 2) a new line approximation method based on curvature segmentation, 3) artifact removal strategies based on geometrical analysis, and 4) stroke segmentation rules based on splitting, merging and directional analysis. Using these techniques, we can extract and trace the strokes in an off-line handwritten Chinese character accurately and efficiently.     

基于连笔消除的空间手写字符识别方法

信息的连续采集会造成部分字符存在连笔,进而影响字符识别率.为此,提出一种基于连笔消除的空间手写字符识别方法.将空间手写字符平面化,提取字符拐点和笔画方向特征.为避免笔画的误消除,利用支持向量机把未知字符分为带连笔字符和非连笔字符,通过连笔的书写特征消除连笔,将空间字符轨迹转化为平面字符轨迹,直接用平面字符分类器进行字符识别.实验结果表明,该方法连笔消除效果显著,利用现有字符库即可获得较高的字符识别率.     

有限集手写汉字识别中的笔画分区矩描述特征

提出了一种笔画分区矩特征的提取方法。根据汉字笔画分布特点，利用小波变换将汉字分解为4个方向笔画分量，用分区矩分别描述4个笔画于图像，并采用K—L变换对特征进行降维处理。采用该特征对有限集手写体汉字进行识别，初步实验结果表明该方法十分有效。     

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.     

一种脱机手写汉字书写顺序恢复模型

书写顺序恢复是从静态文本图像中提取动态的字符书写顺序信息,将2维的图像转换为1维的书写位置的时间序列的过程.为了对手写汉字进行书写顺序提取,提出了一种脱机手写汉字书写顺序的恢复模型.该模型首先将汉字分为整字、部件、子部件和笔画4个层次;然后利用4种拆分操作将整字拆分为部件,再将部件拆分为子部件;最后通过定义一组拆分关系与子部件偏序关系之间的对应规则来得到子部件的全序关系.而将子部件作为最基本的恢复单位,其书写顺序可通过对笔画和交叉笔画对进行分类来得到.实验表明,该模型提出的汉字书写顺序恢复方法的恢复结果具有较高的准确率,且处理速度达到了6.9字/s.     

基于形态学变换的有限集手写体汉字识别

以21个金融汉字为研究对象,提出了一种基于数学形态学和弹性网格技术的特征融合方法.在汉字图像上构造弹性网格,利用形态学变换将汉字分解为4个方向笔画分量,分别提取方向特征和笔画穿透数目特征,然后将这两组特征向量的维数和度量统一后组合成复向量的形式,并采用K-L变换降维,去除冗余信息.该方法无需细化,受笔画不规则变形影响较小.实验证明,是一种有效的特征提取方法.     

Recognition-directed recovering of temporal information from handwriting images

This paper analyses a handwriting recognition system for offline cursive words based on HMMs. It compares two approaches for transforming offline handwriting available as two-dimensional images into one-dimensional input signals that can be processed by HMMs. In the first approach, a left–right scan of the word is performed resulting in a sequence of feature vectors. In the second approach, a more subtle process attempts to recover the temporal order of the strokes that form words as they were written. This is accomplished by a graph model that generates a set of paths, each path being a possible temporal order of the handwriting. The recognition process then selects the most likely temporal stroke order based on knowledge that has been acquired from a large set of handwriting samples for which the temporal information was available. We show experimentally that such an offline recognition system using the recovered temporal order can achieve recognition performances that are much better than those obtained with the simple left–right order, and that come close to those of an online recognition system. We have been able to assess the ordering quality of handwriting when comparing true ordering and recovered one, and we also analyze the situations where offline and online information differ and what the consequences are on the recognition performances. For these evaluations, we have used about 30,000 words from the IRONOFF database that features both the online signal and offline signal for each word.     

基于笔画曲率特征的笔迹鉴别方法

现有的手写汉字脱机笔迹鉴别方法存在只能针对特定字符或需要大量样本字符等问题,为此提出一种基于笔画曲率特征的笔迹鉴别方法。首先运用数学形态学对采集的笔迹图像进行预处理,在横、竖、撇、捺四个方向提取具有代表性的笔画骨架,然后对笔画骨架进行圆的重构,提取四个方向笔画圆的曲率作为特征值组成笔迹特征矩,根据待鉴别的笔迹特征矩与数据库中笔迹特征矩向量夹角相似性度量结果对样本做出判断。实验结果表明该文方法对于待鉴别样本字符的内容没有要求,样本字符数量要求低、应用范围广、鲁棒性强。     

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.