一种基于DTW/ISODATA算法的多层分类器手语识别方法

为提高大词汇量手语识别速度,论文提出了一种将动态时间规整(DTW)和隐马尔可夫模型(HMM)相结合的多层次的大词汇量手语识别方法。该方法思想是先进行全局粗略搜索,将要识别的手势词归入某一组范围较小的词表中,然后通过更加精确的HMM局部搜索将词识别出来。各个词汇表用DTW/ISODATA算法来产生。对4942个孤立手语词作了实验,结果表明,相对于仅用HMM单层识别而言,识别速度从原来每个词的2.364秒提高到0.137秒,提高了94.2%,识别准确率也提高了4.66%。     

面向大词汇量的实时连续中国手语识别系统

目前手语识别研究的难点之一在于如何实现大词汇量的连续语句识别，针对这个问题，该文提出了几个有效的方法，包括修正转移矩阵，状态结点的捆绑，快速匹配，在搜索路径中加入词跳转的估计参数等。利用上述技术，该文实现了一个基于数据手套和位置跟踪器的大词汇量的连续的中国手语实时识别系统，对中国手语辞典中收录的5100个词以及一批连续语句作实验，实验结果表明，文中所介绍的技术在提高系统识别速度和准确率方面都很有效。     

基于SRN/HMM的非特定人连续手语识别系统

手语识别是通过计算机提供一种有效而准确的机制将手语翻译成文本或语音。目前最新发展水平的手语识别系统在实际应用中应解决非特定人连续手语问题。提出一种将连续手语识别分解成各弧立词识别的分治方法，用于非特定人连续手语识别。把精简循环网（simple recurrent network,简称SRN）作为连续手语的段边界检测器，把SRN分段结果作为隐马可夫模型（hidden Markov models,简称HMM）框架中的状态输入，在HMM框架里使用网格Viterbi算法搜索出一条最佳手语词路径。实验结果表明，该方法的识别效果比单纯使用HMM要好。     

面向中等词汇量的中国手语视觉识别系统

手语识别的研究和实现具有重要的学术价值和广泛的应用前景．提出了基于混合元捆绑的隐马尔可夫模型（TMHMM）用于视觉手语识别．TMHMM的模型刻画精度接近于连续隐马尔可夫模型，因此能保证最终的识别率不会明显降低，同时通过混合元捆绑降低计算成本，有效地提高识别速度．在特征提取方面，提出的层次型特征描述方案更加适合于中等或更大词汇量的手语识别．在此基础上。通过集成鲁棒的双手检测、背景去除和瞳孔检测等技术，实现了一个面向中等词汇量的中国手语视觉识别系统．实验结果表明，提出的方法能较好地实现常规背景中的中等词汇量的手语识别．     

具有不同数目状态结点的HMMs在中国手语识别中的应用

中国手语是中国聋人使用的语言,主要通过手势动作来表达一定的含义。因而,手语识别问题是动态连续信号的识别问题。目前大部分手语识别系统采用HMMs(hidden Markov models)作为系统的识别系统。由于各个词包含的基本手势数不同,若所有模型都由同样数目的状态结点构成会影响识别率。而由人为每个词设置状态数又很难达到完全准确,所述系统使用一种基于动态规划的估计状态结点数的办法,并实现了基于具有不同状态数目的HMM的训练及识别过程,实验结果表明,该系统在手语的识别速度和识别精度方面都有所提高。     

基于SOFM/HMM模型的非特定人手语识别系统

手语识别是通过计算机提供一种有效而准确的机制将手语翻译成文本或语音。目前最新发展水平的手语识别系统在实际应用中应该解决非特定人手语识别问题。该文在分析非特定人手语识别特点－数据多且差异大、模型训练难收敛、对不同人数据的特征提取需求更迫切－的基础上，提出了SOFM／HMM模型，将自组织特征映射（SOFM）很强的特征提取功能和隐马可夫模型（HMM）良好的处理时间序列属性结合在一个新颖的框架下，并把该模型应用到非特定人中国手语识别中，实验结果表明，SOFM／HMM模型手语识别率比传统的HMM模型提高近5％。     

一种基于SCHMM的手语识别方法

手语识别的研究具有重大的学术价值和广泛的应用前景.在近些年的手语识别工作中,隐马尔科夫模型(HiddenMarkov Models,简称HMMs)起到了重要的作用.基于HMM的统计框架是当前动态识别领域的主流方法,同时也是该文的研究工作的理论基础.提出将半连续隐马尔科夫模型(SCHMM)用于手语识别,在理论上证明了SCHMM优于离散隐马尔科夫模型(DHMM)和连续隐马尔科夫模型(CHMM),可以避开DHMM中因矢量量化造成的信息损失,在保证识别率的前提下降低模型的复杂性和运算量.     

手语识别方法与技术综述

手语作为聋哑人和健听人的主要交流渠道,在日常生活中发挥着十分重要的作用。随着计算机视觉领域和深度学习领域的高速发展,手语识别领域也迎来了新的机遇。对近年来基于计算机视觉的手语识别研究中使用的先进方法和技术进行了综述。从静态手语、孤立词和连续语句识别三个分支出发,系统地阐述了手语识别常用方法和技术难点。详细介绍了图像预处理、检测与分割、跟踪、特征提取、分类等手语识别步骤。总结分析了手语识别常用的算法和神经网络模型,归纳整理了常用手语数据集,并对不同语种识别现状进行了分析,探讨了手语识别面临的挑战与限制。     

基于SCHMM的手语识别方法的实验研究

在近些年的手语识别工作中,HMM起到了重要的作用。提出将SCHMM用于手语识别,实验结果表明SCHMM优于离散隐马尔科夫模型（DHMM）和连续隐马尔科夫模型（CHMM）,可以避开DHMM中因矢量量化造成的信息损失,在保证识别率的前提下降低模型的复杂性和运算量。     

基于二阶隐马尔可夫模型的连续手语识别

在传统的一阶隐马尔可夫模型(HMM1)中,状态序列中的每一个状态被假设只与前一个状态有关,这样虽然可以简单、有效地推导出模型的学习和识别算法,但也丢失了许多从上文传递下来的信息.因此,在传统一阶隐马尔可夫模型的基础上,为了解决手语识别困难、正确率低的问题,提出了一种基于二阶隐马尔可夫模型(HMM2)的连续手语识别方法....     

A Chinese sign language recognition system based on SOFM/SRN/HMM

In sign language recognition (SLR), the major challenges now are developing methods that solve signer-independent continuous sign problems. In this paper, SOFM/HMM is first presented for modeling signer-independent isolated signs. The proposed method uses the self-organizing feature maps (SOFM) as different signers' feature extractor for continuous hidden Markov models (HMM) so as to transform input signs into significant and low-dimensional representations that can be well modeled by the emission probabilities of HMM. Based on these isolated sign models, a SOFM/SRN/HMM model is then proposed for signer-independent continuous SLR. This model applies the improved simple recurrent network (SRN) to segment continuous sign language in terms of transformed SOFM representations, and the outputs of SRN are taken as the HMM states in which the lattice Viterbi algorithm is employed to search the best matched word sequence. Experimental results demonstrate that the proposed system has better performance compared with conventional HMM system and obtains a word recognition rate of 82.9% over a 5113-sign vocabulary and an accuracy of 86.3% for signer-independent continuous SLR.     

Large vocabulary sign language recognition based on fuzzy decision trees

The major difficulty for large vocabulary sign recognition lies in the huge search space due to a variety of recognized classes. How to reduce the recognition time without loss of accuracy is a challenging issue. In this paper, a fuzzy decision tree with heterogeneous classifiers is proposed for large vocabulary sign language recognition. As each sign feature has the different discrimination to gestures, the corresponding classifiers are presented for the hierarchical decision to sign language attributes. A one- or two- handed classifier and a hand-shaped classifier with little computational cost are first used to progressively eliminate many impossible candidates, and then, a self-organizing feature maps/hidden Markov model (SOFM/HMM) classifier in which SOFM being as an implicit different signers' feature extractor for continuous HMM, is proposed as a special component of a fuzzy decision tree to get the final results at the last nonleaf nodes that only include a few candidates. Experimental results on a large vocabulary of 5113-signs show that the proposed method dramatically reduces the recognition time by 11 times and also improves the recognition rate about 0.95% over single SOFM/HMM.     

基于关键帧的多级分类手语识别研究*

提出了一种基于关键帧识别的多级分类的手语识别方法,该方法采用HDR(多层判别回归)/DTW（动态时间规正）模板匹配多级分类方法。根据手语表达由多帧构成的特点,采用SIFT(尺度不变特征变换)算法定位获取手语词汇的关键帧,并提取其特征向量;根据手语词汇的关键帧采用HDR方法缩小搜索范围,然后采用DTW比较待识别的手语词特征与该范围内每一个手语词进行匹配比较,计算概率最大的为识别结果。这种方法在相同识别率的情况下比HMM识别方法速度提高近8.2%,解决了模板匹配法在大词汇量面前识别率快速下降的问题。     

Large-Vocabulary Continuous Sign Language Recognition Based on Transition-Movement Models

The major challenges that sign language recognition (SLR) now faces are developing methods that solve large-vocabulary continuous sign problems. In this paper, transition-movement models (TMMs) are proposed to handle transition parts between two adjacent signs in large-vocabulary continuous SLR. For tackling mass transition movements arisen from a large vocabulary size, a temporal clustering algorithm improved from k-means by using dynamic time warping as its distance measure is proposed to dynamically cluster them; then, an iterative segmentation algorithm for automatically segmenting transition parts from continuous sentences and training these TMMs through a bootstrap process is presented. The clustered TMMs due to their excellent generalization are very suitable for large-vocabulary continuous SLR. Lastly, TMMs together with sign models are viewed as candidates of the Viterbi search algorithm for recognizing continuous sign language. Experiments demonstrate that continuous SLR based on TMMs has good performance over a large vocabulary of 5113 Chinese signs and obtains an average accuracy of 91.9%