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%.     

基于过程神经元的手写体汉字仿人识别研究

为有效地获取脱机手写体汉字笔划信息,采用过程神经元网络提取手写体汉字基本笔段,分析各类笔段间的拓扑性质,并将手写体汉字图像转化为具有容错表征方式的六种汉字笔划类型在不同位置组成的几何图形.模仿人类汉字形码输入法,统计具有冗余容错形状的笔划类型和相合相交点的数量和位置,建立手写体汉字多维特征知识数据结构表,通过对比和判断仿人容错地识别手写体汉字.对SCUT-IRAC手写体汉字库中汉字进行了实验仿真,该方法具有较强的"认知"手写体汉字的能力.     

计算机实时手写中文自动识别

本文介绍用于联机手写中文字自动识别的新方法与新算法.由于下述各点的实现,手写 文字时可以减少许多限制,增加书写自由.①笔划的抽取经由两次分段实现:首先连续采样, 将输入笔划变换成线段组成,再对线段的长度进行比较,删去相对不重要的成份.②用笔划校 正技术将不应分离的笔划重新组合成规范笔划,或者将不应联写的复合笔划重新分解成基本 笔划.③用非完全匹配技术使失真字可以识别.④用混序笔划重排算法可使一个混序笔划输 入的字重新排列笔顺.⑤笔划位置和长度作为进一步特征,可区别模糊字.     

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.     

Handwritten Chinese character recognition using fuzzy image alignment

The task of handwritten Chinese character recognition is one of the most challenging areas of human handwriting classification. The main reason for this is related to the writing system itself which encompasses thousands of characters, coupled with high levels of diversity in personal writing styles and attributes. Much of the existing work for both online and off-line handwritten Chinese character recognition has focused on methods which employ feature extraction and segmentation steps. The preprocessed data from these steps form the basis for the subsequent classification and recognition phases. This paper proposes an approach for handwritten Chinese character recognition and classification using only an image alignment technique and does not require the aforementioned steps. Rather than extracting features from the image, which often means building models from very large training data, the proposed method instead uses the mean image transformations as a basis for model building. The use of an image-only model means that no subjective tuning of the feature extraction is required. In addition by employing a fuzzy-entropy-based metric, the work also entails improved ability to model different types of uncertainty. The classifier is a simple distance-based nearest neighbour classification system based on template matching. The approach is applied to a publicly available real-world database of handwritten Chinese characters and demonstrates that it can achieve high classification accuracy and is robust in the presence of noise.     

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。     

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。     

基于过程神经网络的手写体汉字识别方法研究

分析手写体汉字各类基本笔画间的拓扑关系,将手写体汉字图像转化为具有容错表征方式的多种汉字笔画类型在不同位置组成的几何图形。采用过程神经元网络提取手写体汉字各类型笔形,统计各类型笔形和相交点的数量,从而建立手写体汉字特征知识的数据结构表。对SCUT IRAC手写体汉字库中汉字进行了实验仿真,该方法大大降低了脱机手写体汉字识别的难度,有较高的汉字识别率。     

基于卷积神经网络和Transformer的手写体英文文本识别

手写体文本识别技术可以将手写文档转录成可编辑的数字文档。但由于手写的书写风格迥异、文档结构千变万化和字符分割识别精度不高等问题,基于神经网络的手写体英文文本识别仍面临着许多挑战。针对上述问题,提出基于卷积神经网络（CNN）和Transformer的手写体英文文本识别模型。首先利用CNN从输入图像中提取特征,而后将特征输入到Transformer编码器中得到特征序列每一帧的预测,最后经过链接时序分类（CTC）解码器获得最终的预测结果。在公开的IAM（Institut für Angewandte Mathematik）手写体英文单词数据集上进行了大量的实验结果表明,该模型获得了3.60%的字符错误率（CER）和12.70%的单词错误率（WER）,验证了所提模型的可行性。     

自然手写汉字FS识别法

提出联机识别自然手写汉字的FS识别法。在剖析五笔字根结构和编码原则基础上,对五笔字根作适应性改造,将键盘输入技术与联机识别技术有机融合的一种识别体系。在多库识别体系中首次采用层间分级技术。分析和实验表明：充分考虑了自然手写汉字书写习惯和结构特征,系统有较高稳定性。     

基于多重规则和路径评价的在线中英文手写识别方法

手写文本识别方法主要应用于文本输入技术,对人机交互领域的发展起关键作用。针对多数在线输入法无法识别中英文混合手写识别的问题,提出一种在线中英文混合手写文本识别方法。通过对文本笔画进行基于水平相对位置、垂直重叠率、面积重叠率规则的整合以及连笔切分,得到一系列字符片段,同时利用笔画个数、宽高比、中心偏离、平滑度等几何特征和识别置信度,对字符片段进行中英文分类。在此基础上,根据分类结果并结合自然语言模型的路径评价及动态规划搜索算法,分别对候选的中、英文字符片段进行合并处理,得到待识别的中、英文字符序列,并将其分别送入卷积神经网络的中、英文识别模型中,得到手写文本识别结果。实验结果表明,在线手写中英文混合文本识别正确率达93.67%,不仅能切分在线手写中文文本行,而且对包含字符连笔的在线手写中英文文本行也有较好的切分效果。     

Cascade Markov random fields for stroke extraction of Chinese characters

Extracting perceptually meaningful strokes plays an essential role in modeling structures of handwritten Chinese characters for accurate character recognition. This paper proposes a cascade Markov random field (MRF) model that combines both bottom-up (BU) and top-down (TD) processes for stroke extraction. In the low-level stroke segmentation process, we use a BU MRF model with smoothness prior to segment the character skeleton into directional substrokes based on self-organization of pixel-based directional features. In the high-level stroke extraction process, the segmented substrokes are sent to a TD MRF-based character model that, in turn, feeds back to guide the merging of corresponding substrokes to produce reliable candidate strokes for character recognition. The merit of the cascade MRF model is due to its ability to encode the local statistical dependencies of neighboring stroke components as well as prior knowledge of Chinese character structures. Encouraging stroke extraction and character recognition results confirm the effectiveness of our method, which integrates both BU/TD vision processing streams within the unified MRF framework.     

脱机手写满文笔画基元的提取和识别

笔画的正确提取对文字识别结果至关重要。该文提出并实现了一种全新的满文笔画提取方法。基于满文文字的结构和特征,首先对处理目标进行预处理,确定笔画主干,创建笔画生长法对满文文字笔画实现自动提取。对提取得到的笔画进行分类,然后对照笔画特征库进行识别。试验表明,该方法对规整手写的满文文字的笔画提取和识别有令人满意的效果,为进一步脱机手写满文识别研究奠定了坚实的基础。     

基于组件合并的手写体汉字串分割

人们对孤立的手写体汉字字符的离线 识别做了大量的研究工作,而走向实用化的进展并不快.除了单字识别率不理想以外,从文本 中正确分割出单个汉字字符也是一个主要难题,因为字符的识别离不开正确分割.利用汉字的 基本结构特征,根据两个组件之间的上下、左右和包围关系,对组件进行合并形成完整的汉字 图像.对整个汉字字符串中组件的宽度和相邻组件的间距进行分析,有助于左右关系组件的合 并.实验结果表明,该方法对手写体汉字字符串具有理想的分割效果.     

汉字手写式键盘输入方法的设计与实现

设计了一种汉字手写式键盘输入法,给出了基于快速模糊匹配方法的笔画智能生成算法及其实现。该方法在键盘上将汉字笔画模拟表示为笔画轨迹的起点、拐点、中间点和落点的键序列,通过构造笔画的网状搜索空间,实现了键序列到笔画序列集合的转换,进而实现汉字输入。本方法无需记忆键位,会写汉字就会输入。     

On-line handwritten Chinese character recognition via a fuzzy attribute representation

Chinese characters are constructed by strokes according to structural rules. Therefore, the geometric configurations of characters are important features for character recognition. In handwritten characters, stroke shapes and their spatial relations may vary to some extent. The attribute value of a structural identification is then a fuzzy quantity rather than a binary quantity. Recognizing these facts, we propose a fuzzy attribute representation (FAR) to describe the structural features of handwritten Chinese characters for an on-line Chinese character recognition (OLCCR) system. With a FAR. a fuzzy attribute graph for each handwritten character is created, and the character recognition process is thus transformed into a simple graph matching problem. This character representation and our proposed recognition method allow us to relax the constraints on stroke order and stroke connection. The graph model provides a generalized character representation that can easily incorporate newly added characters into an OLCCR system with an automatic learning capability. The fuzzy representation can describe the degree of structural deformation in handwritten characters. The character matching algorithm is designed to tolerate structural deformations to some extent. Therefore, even input characters with deformations can be recognized correctly once the reference dictionary of the recognition system has been trained using a few representative learning samples. Experimental results are provided to show the effectiveness of the proposed method.     

基于模板匹配的移动设备手写汉字笔画识别

针对当前移动设备上手写汉字流行的[xml]文件存储格式,提出了一种对用户字笔画与模板字笔画测试匹配的算法,该算法通过方位、拓扑关系和形状3种特征综合量度笔画间的匹配,实验效果良好。该算法在用户字的多笔少笔判别、笔顺的正误性判别、整字的正确性以及工整性判别等方面都有着广泛的应用。     

基于小波变换的图像汉字笔划特征提取方法

借鉴仿生模式识别的认知观点,从汉字的构造机理和人类认识汉字的习惯角度出发,提出一种基于小波变换的图像汉字识别方法。制定了图像汉字笔划特征提取的具体规则,采用小波变换的方法对图像汉字边缘和笔划轮廓进行检测,通过有效提取图像汉字笔段信息,进行笔段合成,生成汉字或汉字的基本笔划。仿真实验结果表明,这种方法提高了图像汉字笔划特征提取的准确率和稳定性,对于印刷体和书写较规范的手写体图像汉字具有极高的识别率。