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.     

面向连续字符识别的手写汉字部件集及统计规律

本文面向手写字符序列输入信号连续识别研究,分析了汉字及联机手写文本的特点,提出并构建了手写汉字部件集。基于该部件集,完成了GB2312-80的6,763个汉字的部件拆分编码和部件集的测试。统计编码数据发现,汉字依手写部件数的分布规律呈对数正态分布。本文从统计学和字符识别技术的角度对手写部件的构字能力作了分析和讨论,部件集的设计方案在部件选择和汉字拆分上均满足设计要求。实验表明,基于手写部件构造的部件识别器对手写汉字和连续汉字的部件识别率分别达到70.21%和58.49%。     

小类别数手写汉字建模

在手写汉字识别的研究中,鲜有研究者提出建立手写汉字的数学模型,本文在这方面作了一些探讨。建模的目的通常有两个:一是手写汉字的表示或描述,二是手写汉字的识别。本文针对小类别数手写汉字,在骨架图形的基础上,把手写汉字看作孤枝、孤环和部件的集合,并定义三者之间的方位关系,从而建立手写汉字的数学模型。实验表明,该模型用于识别,效果良好。     

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。     

基于基元模糊关系的手写汉字识别

手写汉字中笔划，部件及其位置关系均产生较大变化，这种变化是引起手写汉字特征不稳定的主要因素。为了减小上述不利影响，使手写汉字特征的描述趋于稳定，本文给出了一种基于汉字基元之间的模糊关系识别手写汉字的方法。     

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%.     

识别手写汉字的基元模糊关系法

手写汉字中笔划、部件及其位置关系均产生较大变化,这种变化是引起手写汉字特征不稳定的主要因素。为了减小上述不利影响,使手写汉字特征的描述趋于稳定,文章给出了一种基于汉字基元之间的模糊关系识别手写汉字的方法,用汉字基元之间的模糊关系来描述汉字的结构,其优点:一是对汉字基元之间相对位置的变化有较强的适应性,二是不需要对一个汉字中的各个基元在二维平面内进行复杂地排序,汉字的结构可以简化为一个基元模糊关系的集合。     

基于候选特征笔画和多类阈值的手写汉字切分

通过分析汉字的常见结构,鉴于汉字与汉字之间的距离和构成汉字的部件之间的距离的显著差异性,提出一种基于候选特征笔画和多类阈值的手写汉字切分方法.首先从构成手写汉字的笔画集合中提取候选特征笔画,根据候选特征笔画将手写汉字预切分,然后利用基于间距阈值的部件组合规则对过切分的汉字部件进行组合,最后采用基于单字宽度阈值的粘连汉字判断规则搜索粘连汉字,对粘连汉字进行递归切分.实验表明,该方法对连续手写汉字的切分准确率较高,具有一定的实用性.     

基于笔顺自由及连笔的联机手写汉字识别

提出了一种基于笔顺重排算法的手写汉字识别。将手写汉字的可见线段和不可见线段进行联合编码,并 采用了一种基于单字切分及基本笔顺表的识别方法。首先将单字分解为部件,根据分解的结构,对字典进行粗略的过滤,将字典中不符合待识别汉字拆分结构的字排除,然后根据笔划编码进行识别,有效提高了笔划的匹配速度,较好地解决了联机手写汉字识别中连笔及笔顺自由问题。     

基于分位数的手写汉字识别方法

以往的手写汉字识别方法,无论应用何种特征提取方法,在生成标准模板时,一般都采用样本特征的算术平均值。文章提出了一种使用样本特征的分位数组合生成标准模板的方法,通过其在手写汉字识别中的应用表明,该方法比基于均值的标准模板有更好的鲁棒性,且在不增加任何计算量和算法复杂度的前提下,使系统的识别性能有所提高;同时该算法还有很好的推广性能,可以应用到各种特征提取算法中。     

Handwritten Chinese radical recognition using nonlinear active shape models

Handwritten Chinese characters can be recognized by first extracting the basic shapes (radicals) of which they are composed. Radicals are described by nonlinear active shape models and optimal parameters found using the chamfer distance transform and a dynamic tunneling algorithm. The radical recognition rate is 96.5 percent correct (writer-independent) on 280,000 characters containing 98 radical classes.     

Handwritten Chinese character recognition using nonlinear active shape models and the Viterbi algorithm

Since Chinese characters are composed from a small set of fundamental shapes (radicals) the problem of recognising large numbers of characters can be converted to that of extracting a small number of radicals and then finding their optimal combination. In this paper, radical extraction is carried out by nonlinear active shape models, in which kernel principal component analysis is employed to capture the nonlinear variation. Treating Chinese character composition as a discrete Markov process, we also propose an approach to recognition with the Viterbi algorithm. Our initial experiments are conducted on off-line recognition of 430,800 loosely-constrained characters, comprised of 200 radical categories covering 2154 character categories from 200 writers. The correct recognition rate is 93.5% characters correct (writer-independent). Consideration of published figures for existing radical approaches suggests that our method achieves superior performance.     

基于相空间重构和支持向量机的和弦识别

利用相空间重构方法提取和弦音频中非线性特征参量,将部分参量作为训练集来构造支持向量机（SVM）分类器,另一部分作为测试集进行识别效果的检验,仿真实验表明,基于相空间重构和支持向量机的方法能够有效地进行和弦的识别,可以进一步应用到连续的音乐识别当中。     

结合非线性全局特征和谱特征的脑电情感识别

针对现有表征情感信息的脑电信号的非线性特征提取不完善的问题,将相空间重构技术引入情感脑电的识别中,提取了在相空间重构下基于轨迹的描述轮廓的三种非线性几何特征作为新的情感脑电特征。结合脑电信号的功率谱熵以及非线性属性特征（近似熵、最大Lyapunov指数、Hurst指数）,提出了基于主成分分析（PCA）的非线性全局特征（非线性几何特征+非线性属性特征）和功率谱熵的融合算法,以支持向量机（SVM）为分类器进行情感识别。结果显示,非线性全局特征能更有效地实现情感识别,二分类情感识别率约90%左右。基于PCA的融合情感特征相比单一特征能达到更佳的情感识别性能,四分类实验中平均识别率可达86.42%。结果表明,非线性全局特征相比非线性属性特征情感识别率有所提高,非线性全局特征以及功率谱熵的结合可以构造出更佳的情感脑电特征参数。     

基于非线性时序模型的神经网络图形识别方法

提出了复数域非线性指数自回归(CNEAR)图形轮廓建模方法.构造了用于CNEAR 模型参数估计的神经网络模型,利用该网络可解决非线性参数的估计问题.CNEAR模 型参数具有平移、旋转和比例不变性并与计算起始点的选择无关.基于模型参数构造了特征 向量,并设计了复数神经网络分类器,给出了复数神经网络学习算法.实验结果表明CNEAR 模型在较低阶次即能获得较高的识别率,CNEAR模型对带噪声图形及形状差别较小图形的 识别效果要好于复数域自回归模型方法.     

Local association based recognition of two-dimensional objects

A model based two-dimensional object recognition system capable of performing under occlusion and geometric transformation is described in this paper. The system is based on the concept of associative search using overlapping local features. During the training phase, the local features are hashed to set up the associations between the features and models. In the recognition phase, the same hashing procedure is used to retrieve associations that participate in a voting process to determine the identity of the shape. Two associative retrieval techniques for discrete and continuous features, respectively, are described in the paper. The performance of the system is studied using a test set of 1,000 shapes that are corrupted versions of 100 models in the shape database. It is shown that the incorporation of a verification phase to confirm the retrieved associations can provide zero error performance with a small reject rate.     

A model-based hand gesture recognition system

This paper introduces a model-based hand gesture recognition system, which consists of three phases: feature extraction, training, and recognition. In the feature extraction phase, a hybrid technique combines the spatial (edge) and the temporal (motion) information of each frame to extract the feature images. Then, in the training phase, we use the principal component analysis (PCA) to characterize spatial shape variations and the hidden Markov models (HMM) to describe the temporal shape variations. A modified Hausdorff distance measurement is also applied to measure the similarity between the feature images and the pre-stored PCA models. The similarity measures are referred to as the possible observations for each frame. Finally, in recognition phase, with the pre-trained PCA models and HMM, we can generate the observation patterns from the input sequences, and then apply the Viterbi algorithm to identify the gesture. In the experiments, we prove that our method can recognize 18 different continuous gestures effectively. Received: 19 May 1999 / Accepted: 4 September 2000     

A composite spatio-temporal modeling approach for age invariant face recognition

In this research we propose a novel method of face recognition based on texture and shape information. Age invariant face recognition enables matching of an image obtained at a given point in time against an image of the same individual obtained at an earlier point in time and thus has important applications, notably in law enforcement. We investigate various types of models built on different levels of data granularity. At the global level a model is built on training data that encompasses the entire set of available individuals, whereas at the local level, data from homogeneous sub-populations is used and finally at the individual level a personalized model is built for each individual. We narrow down the search space by dividing the whole database into subspaces for improving recognition time. We use a two-phased process for age invariant face recognition. In the first phase we identify the correct subspace by using a probabilistic method, and in the second phase we find the probe image within that subspace. Finally, we use a decision tree approach to combine models built from shape and texture features. Our empirical results show that the local and personalized models perform best when rated on both Rank-1 accuracy and recognition time.