Recognition of handprinted Kanji characters by the stroke matching method

This paper describes an improved stroke matching method for the recognition of handprinted Kanji characters. Using the stroke feature and two additional global features, a recognition rate of over 90% has been obtained for about 1000 Kanji characters.     

On-line recognition of handprinted Kanji characters

Difficulties in Kanji (Chinese character) recognition stem from its large character set (about 5000 characters) and the large number of strokes (up to about sixty) in each character.

The paper describes a preliminary approach to this Kanji recognition problem. In the present method, a handprinted Kanji character is coded into a symbol string using the binary relation between stroke and reference zone. Two symbol string recognition methods are proposed and investigated; the direct matching recognition (DMR) method and the unit structure recognition (USR) method.

The DMR method worked efficiently for characters which have up to five strokes. The USR method represents Kanji characters with a structural unit combination. This method worked efficiently for multi-stroke characters and greatly reduced dictionary update labor.     

Dual classifier system for handprinted alphanumeric character recognition

This paper presents a dual classifier handprinted character recognition system that is implemented using Radial Basis Function (RBF) networks. Each classifier in the system extracts a different set of features from the input character and makes its own indpendent classification decision. The features used are the diagonal and partitioned radial projections, and the four-directional edge maps of the mage. The system then combines these decisions before giving a final classification output. Several different methods of desinging the combiner are examined. The proposed system is tested on a database of handprinted alphanumeric characters, and the results are fourd to be very promising.     

On-line computer recognition of proposed standard ANSI(USASI) handprinted characters

A robust real-time system for recognition of handprinted characters of the upper case English alphabet is described. The basic system is suited to implementation on small computers and has been designed to accept characters conforming to the stroke types and sequences suggested by a proposed ANSI(USASI) standard. Experiments with 2340 samples from 10 untrained subjects yielded an overall character recognition accuracy of 98.3%. The system is quite robust with respect to size and stylistic variations. The robustness and real-time operation of the system are largely attributed to the preprocessing and stroke identification techniques developed, which include a new two-stage syntactic classifier for the identification of curvilinear strokes.     

基于跨模态深度度量学习的甲骨文字识别

甲骨文字图像可以分为拓片甲骨文字与临摹甲骨文字两类.拓片甲骨文字图像是从龟甲、兽骨等载体上获取的原始拓片图像,临摹甲骨文字图像是经过专家手工书写得到的高清图像.拓片甲骨文字样本难以获得,而临摹文字样本相对容易获得.为了提高拓片甲骨文字识别的性能,本文提出一种基于跨模态深度度量学习的甲骨文字识别方法,通过对临摹甲骨文字和...     

Handprinted word recognition on a NIST data set

An approach to handprinted word recognition is described. The approach is based on the use of generating multiple possible segmentations of a word image into characters and matching these segmentations to a lexicon of candidate strings. The segmentation process uses a combination of connected component analysis and distance transform-based, connected character splitting. Neural networks are used to assign character confidence values to potential character within word images. Experimental results are provided for both character and word recognition modules on data extracted from the NIST handprinted character database.     

手写体汉字识别问题综论

本文在讨论了人对汉字的认知心理试验研究结果之后,认为人类的汉字识别是经由整字属性及分层结构的多种途径复合而成的。这些途径中的大多数都可以在手写体汉字的机器识别中模仿运用。由此可把汉字的机器识别方法归纳为整模式法和子模式法两个大类,对它们的有利方面和困难方面进行了讨论;对影响其性能的因素进行了分析;对识别率以及它与识别字集大小和后处理等的关系提出了评估的问题。     

混合模式识别系统研究

讨论基于多种分类方法的模块组合实现的混合模式识别系统，它不同于利用多分类器输出结果表决的集成系统。提出两个系统：一个面向刷体汉字文本识别，另一个面策自由手写体字识别。     

Recognition of handprinted Hebrew characters using features selected in the Hough transform space

Automatic identification of handprinted Hebrew characters is described in this paper. The recognition model devised constitutes a multi-stage system. In the first stage a coarse classifier allocates the input patterns into one of 17 categories, based on the number and the location of end points within predetermined regions in the characters matrix. The second stage uses features extracted in the Hough transform space to classify characters assigned to each of 16 categories. The remaining one category, composed of similar, square-like (rotated L shape) classes, is recognized by structural analysis and a statistical classifier. An additional step of postprocessing is added to compensate for the sensitivity of the Hough transform to the existence of similar classes within some of the categories. Experiments were conducted with a multi-author (40 writers) data base. An average recognition rate of 86.9% was observed for the system. This compared favorably with the results of two other recognition methods.     

Empirical tests for feature selection based on a psychological theory of character recognition

It is argued that machine algorithms based on feature detection promise the greatest chance for success in the recognition of isolated, unconstrained handprinted characters. In order to match human performance, the features used cannot be chosen in an arbitrary manner; they must have some psychological significance. A theory of characters based on functional attributes is reviewed, and three psychophysical tests are described for determining the psychological validity of any postulated attribute. The first test indicates if a particular attribute is involved in a particular letter, and the second and third tests investigate the commonality of an attribute among different letters.     

CHITRA: Cognitive handprinted input-trained recursively analyzing system for recognition of alphanumeric characters

A novel system for recognition of handprinted alphanumeric characters has been developed and tested. The system can be employed for recognition of either the alphabet or the numeral by contextually switching on to the corresponding branch of the recognition algorithm. The two major components of the system are the multistage feature extractor and the decision logic tree-type catagorizer. The importance of good features over sophistication in the classification procedures was recognized, and the feature extractor is designed to extract features based on a variety of topological, morphological and similar properties. An information feedback path is provided between the decision logic and the feature extractor units to facilitate an interleaved or recursive mode of operation. This ensures that only those features essential to the recognition of a particular sample are extracted each time. Test implementation has demonstrated the reliability of the system in recognizing a variety of handprinted alphanumeric characters with close to 100% accuracy.Most of this work was carried out at the School of Automation, Indian Institute of Science, Bangalore, India.     

基于多任务联合判别稀疏表示的人脸识别

针对人脸识别中由于姿态、光照及噪声等影响造成的识别率不高的问题,提出一种基于多任务联合判别稀疏表示的人脸识别方法。首先提取人脸的局部二值特征,并基于多个特征建立一个联合分类误差与表示误差的过完备字典学习目标函数。然后,使用一种多任务联合判别字典学习方法,将多任务联合判别字典与最优线性分类器参数联合学习,得到具有良好表征和鉴别能力的字典及相应的分类器,进而提高人脸识别效果。实验结果表明,所提方法相比其他稀疏人脸识别方法具有更好的识别性能。     

基于统计与神经元方法相结合的手写体相似字识别

本文提出了一种基于统计识别方法与人工神经元网络相结合的手写体相似汉字识别方法。该方法充分利用了统计识别方法和神经元网络识别方法的优点,不仅显著地提高了相似字的识别率,而且有效地提高了系统的整体性能。对相似字的识别率由79.02%提高到84.32% ,提高了五个百分点,整体识别率提高了1.3个百分点。     

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.     

Neural Network Recognition of Hand-printed Characters

Character recognition systems can contribute tremendously to the advancement of the automation process, and can improve the interaction between man and machine in many applications, including office automation, cheque verification and a large variety of banking, business and data entry applications.The main theme of this paper is the automatic recognition of hand-printed Latin characters using artificial neural networks in combination with conventional techniques. This approach has a number of advantages: it combines rule-based (structural) approach for feature extraction and non-linea classification tests for recognition; it is more efficient for large and complex data sets; feature extraction is inexpensive and execution time is independent of handwriting style and size. The technique can be divided into three major steps: The first step is pre-processing in which the original image is transformed into a binary image utilising a 300 dpi scanner and then thinned using a parallel thinning algorithm. Second, the image-skeleton is traced from left to right in order to build a binary tree. Some primitives, such as Straight lines, Curves and Loops, are extracted from the binary tree. Finally, a three layer artificial neural network is used for character classification. The system was tested on a sample of handwritten characters from several individuals whose writing ranged from acceptable to poor in quality and the correct average recognition rate obtained using cross-validation was 86%.     

Recognition of handprinted characters by an outermost point method

A recognition system for handprinted characters has been developed for reading sets of characters consisting of a mixture of numerical, alphabetic and Japanese “katakana” characters, a total of 82 symbols.This paper describes a simple convex hull method used for extracting concavity and convexity. The convex hull is constructed by finding the outermost points through tracing the contours of a character. When this system was applied to data consisting of 16,400 characters, a very high level of performance was achieved. The system also automatically compiles a dictionary.     

基于ANN的哈萨克文手写文字识别系统的研究

光学字符识别系统在自动处理,人机交互,办公自动化以及商业领域中有非常广泛的应用。论文主要讨论如何结合结构方法和神经网络的技术,来实现哈萨克语手写文字识别系统的实现。该方法有以下几个优点：方法使用了基于规则（结构）的方法和分类测试;方法更加适合于像哈萨克文字一样具有较大的字符集和字符尺寸不一致的字符集;特征提取的代价较低,运行时间主要由字符尺寸和字体决定。该系统使用一个五层的人工神经网络对字符进行分类,使用10个用户的不同的手写字体进行测试,正确识别率为91%。     

A new representation of shape and its use for high performance in online Arabic character recognition by an associative memory

The purpose of this study is to investigate a new representation of shape and its use in handwritten online character recognition by a Kohonen associative memory. This representation is based on the empirical distribution of features such as tangents and tangent differences at regularly spaced points along the character signal. Recognition is carried out by a Kohonen neural network trained using the representation. In addition to the Euclidean distance traditionally used in the Kohonen training algorithm to measure the similarities among feature vectors, we also investigate the Kullback–Leibler divergence and the Hellinger distance, functions that measure distance between distributions. Furthermore, we perform operations (pruning and filtering) on the trained memory to improve its classification potency. We report on extensive experiments using a database of online Arabic characters produced without constraints by a large number of writers. Comparative results show the pertinence of the representation and the superior performance of the scheme.