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1.
语音谱参数的增强双预测多级矢量量化的码本设计方法   总被引:1,自引:0,他引:1  
表征语音谱参数的线性预测编码(LPC)参数被广泛用于各种语音编码算法。甚低位率语音编码算法要求使用尽可能少的位率编码语音谱参数。文章提出了语音谱参数的增强双预测多级矢量量化算法(EDPMSVQ)的码本设计方法。这种改进的多级矢量量化方法充分利用语音谱参数的短时相关和长时相关特性,采用了有记忆的多级矢量量化算法(MSVQ),对语音谱参数的每一维分别使用不同的预测系数;并且通过利用相邻语音帧间语音谱参数的强相关和弱相关的不同特点,采用了分别对应于强相关和弱相关的两个预测值集合,进一步减小了语音谱参数编码位率。增强双预测多级矢量量化方法能够实现20位的语音谱参数近似“透明”量化,同时能够使语音谱参数量化时的计算复杂度略有减少,所需的存储空间大为减少。  相似文献   

2.
矢量量化技术是一种既能高效压缩码率,又能保证语音质量的编码方法。本文在介绍矢量量化技术的基础上,介绍了COVQ算法及其改进算法CAWVQ算法,最后给出了CAWVQ算法的性能评价,得出如下结论:CAWVQ的优点在于,在时变噪声信道中能够以较少的存储量和运算复杂度,获得接近COVQ的性能。  相似文献   

3.
提出了语音谱参数的切换双预测多级矢量量化算法(DPMSVQ) 的码本设计方法。这种改进的多级矢量量化方法充分利用语音谱参数的短时相关和长时相关特性,采用了有记忆的多级矢量量化算法(MSVQ);并且通过利用相邻语音帧间语音谱参数的强相关和弱相关的不同特点,采用了分别对应于强相关和弱相关的两个预测值,进一步减小了语音谱参数编码位率。切换双预测多级矢量量化方法能够实现21位的语音谱参数近似“透明”量化,同时能够使语音谱参数量化时的计算复杂度略有减少,所需的存储空间大为减少。  相似文献   

4.
对自组织特征映射(SOFM)神经网络学习算法作了简单介绍。从SOFM神经网络学习算法的基本思想出发,通过研究SOFM学习算法在设计矢量码书中存在的问题,提出了一种改进算法。最后把这种算法应用在口电话语音压缩编码的参数矢量量化上。计算机仿真结果表明,SOFM神经网络是一种训练语音码书的好工具,改进的SOFM学习算法能够大大减少训练时间,提高整个系统的性能。  相似文献   

5.
线谱对参数预测多级矢量量化联合优化算法   总被引:1,自引:0,他引:1  
提出了一种线谱对参数预测多级矢量量化联合优化算法.该算法对预测系数和多级矢量量化采用渐进闭环设计,通过迭代实现预测系数和多级矢量量化设计的联合优化.在多级矢量量化设计过程中,采用迭代优化实现多级码本的联合优化.采用语音线谱对参数对量化算法进行测试.测试结果表明,与传统算法相比,该量化算法可以减小线谱对参数量化失真.提高编码语音质量.  相似文献   

6.
对自组织特征映射(SOFM)神经网络学习算法进行阐述.讨论SOFM神经网络学习算法,通过研究基于SOFM学习算法的矢量码书设计中存在的问题,提出一种改进算法.最后把这种算法应用在IP电话语音压缩编码的参数矢量量化上.计算机仿真结果表明,SOFM神经网络对于语音码书训练是非常有效的,改进的SOFM学习算法能够大大减少训练时间,提高整个系统的性能.  相似文献   

7.
采用模糊聚类C均值聚类确定型心改进LBG算法,实现语音参数MFCC码本的矢量量化,实验结果表明,该算法有着与单一LBG算法相近的量化误差,自适应确定码本大小码,码本尺寸显著降低,减小码本的存储量。  相似文献   

8.
为了克服低速率声码器因清浊音硬判决、粗判决而导致解码语音有帧过渡等不自然感的缺陷,在分析比较目前主流声码器编码算法中激励参数提取和量化算法的基础上,将模糊数学中的隶属度概念引入语音子带清浊音描述中,提出了5维的浊音隶属度矢量概念,用于精细描述语音丰富的激励信息;介绍了浊音隶属度矢量的提取算法;提出了矢量量化码本的模糊聚类与LBG级联训练算法(F-LBG);用提取算法提取、建立了浊音隶属度码本的训练样本集,用F-LBG训练了浊音隶属度码本;将提取算法和F-LBG法训练得到的浊音隶属度码本分别应用于正弦激励声码器、混合激励声码器和同态声码器进行语音编、解码仿真;结果表明,用浊音隶属度矢量描述和合成语音激励信号的算法,具有较高的准确性和较强的噪声鲁棒性。  相似文献   

9.
徐军  叶澄清 《计算机科学》2000,27(12):95-96
1 引言 Linde、Buzo和Gray在1980年提出的LBG算法一直是设计矢量量化器的经典算法。码书设计是基于矢量量化图像编码的关键技术。矢量量化的研究主要围绕着降低码率,减小失真和降低复杂度(空间、时间)这三者之间来展开的。码率、失真和复杂度是矢量量化的三个关键要素。自从LBG算法被提出以来,许多学者对矢量量化用于图像压缩提出了大量改进算  相似文献   

10.
本文对神经网络语音识别中的语音特征提取、网络结构以及学习算法进行了初步的研究,提出了一种用于时特征矢量量化的简化和改进的自组织神经网络模型VQNN。VQNN中引入了动态规划法估计语音样本矢量的码本类中心初值并确定网络的初始权矩阵,可构造出256个量化等级的码本矢量。该方法具有较强的鲁棒性且矢量量化过程简单迅速。对28个地名的语音量化识别实验结果表明了这种量化方法对时识别的有性。  相似文献   

11.
讨论了Pal等的广义学习量化算法(GLVQ)和Karayiannis等的模糊学习量化算法(FGLVQ)的优缺点,提出了修正广义学习量化(RGLVQ)算法。该算法的迭代系数有很好的上下界,解决了GLVQ的“Scale”问题,又不像FGLVQ算法对初始学习率敏感。用IRIS数据集对算法进行了测试,并应用所给算法进行了用于图像压缩的量化码书设计。该文算法与FGLVQ类算法性能相当,但少了大量浮点除法,实验过程表明节约训练时间约l0%。  相似文献   

12.
多维流序列并行预测算法研究   总被引:1,自引:0,他引:1  
提出并行算法MSSF-VQ(Multiple Sequential Stream Forecast algorithm based on Vector Quantization),以解决多维序列流的未来趋势预测问题.算法利用矢量空间表示序列流的计算模型,并采用量子化技术离散处理连续序列流,然后提出了序列流矢量概率树的构造算法和搜索算法,最后阐述了算法步骤.真实流序列上的实验结果表明,MSSF-VQ算法预测的准确率高,速度快,在线处理占用的空间小,并有良好的扩展性.  相似文献   

13.
基于模糊矢量量化图象编码的研究   总被引:4,自引:0,他引:4       下载免费PDF全文
分析了模糊矢量量化(FVQ)图象编码的原理,给出了FVQ设计三要素。提出了用于图象编码的指数型模糊矢量量化算法(FVQE)。实验结果表明,FVQE的图象编码性能与FVQ相当,但收敛速度要略快于FVQ算法。  相似文献   

14.
An axiomatic approach to soft learning vector quantization andclustering   总被引:11,自引:0,他引:11  
This paper presents an axiomatic approach to soft learning vector quantization (LVQ) and clustering based on reformulation. The reformulation of the fuzzy c-means (FCM) algorithm provides the basis for reformulating entropy-constrained fuzzy clustering (ECFC) algorithms. According to the proposed approach, the development of specific algorithms reduces to the selection of a generator function. Linear generator functions lead to the FCM and fuzzy learning vector quantization algorithms while exponential generator functions lead to ECFC and entropy-constrained learning vector quantization algorithms. The reformulation of LVQ and clustering algorithms also provides the basis for developing uncertainty measures that can identify feature vectors equidistant from all prototypes. These measures are employed by a procedure developed to make soft LVQ and clustering algorithms capable of identifying outliers in the data set. This procedure is evaluated by testing the algorithms generated by linear and exponential generator functions on speech data.  相似文献   

15.
矢量量化的遗传k-均值算法   总被引:2,自引:0,他引:2  
刘伟  王磊 《计算机工程》2003,29(21):94-96
提出了一种遗传k-均值算法,该算法通过改进标准遗传操作及采用可变变异率,使其在矢量量化应用中表现出很好的性能.实验证明,该算法能够获得质量高于k-均值和模糊k-均值算法的矢量量化码书,为设计全局最优码书提供了新思路。  相似文献   

16.
Derives an interpretation for a family of competitive learning algorithms and investigates their relationship to fuzzy c-means and fuzzy learning vector quantization. These algorithms map a set of feature vectors into a set of prototypes associated with a competitive network that performs unsupervised learning. Derivation of the new algorithms is accomplished by minimizing an average generalized distance between the feature vectors and prototypes using gradient descent. A close relationship between the resulting algorithms and fuzzy c-means is revealed by investigating the functionals involved. It is also shown that the fuzzy c-means and fuzzy learning vector quantization algorithms are related to the proposed algorithms if the learning rate at each iteration is selected to satisfy a certain condition  相似文献   

17.
Soft learning vector quantization   总被引:3,自引:0,他引:3  
Seo S  Obermayer K 《Neural computation》2003,15(7):1589-1604
Learning vector quantization (LVQ) is a popular class of adaptive nearest prototype classifiers for multiclass classification, but learning algorithms from this family have so far been proposed on heuristic grounds. Here, we take a more principled approach and derive two variants of LVQ using a gaussian mixture ansatz. We propose an objective function based on a likelihood ratio and derive a learning rule using gradient descent. The new approach provides a way to extend the algorithms of the LVQ family to different distance measure and allows for the design of "soft" LVQ algorithms. Benchmark results show that the new methods lead to better classification performance than LVQ 2.1. An additional benefit of the new method is that model assumptions are made explicit, so that the method can be adapted more easily to different kinds of problems.  相似文献   

18.
Fuzzy algorithms for learning vector quantization   总被引:14,自引:0,他引:14  
This paper presents the development of fuzzy algorithms for learning vector quantization (FALVQ). These algorithms are derived by minimizing the weighted sum of the squared Euclidean distances between an input vector, which represents a feature vector, and the weight vectors of a competitive learning vector quantization (LVQ) network, which represent the prototypes. This formulation leads to competitive algorithms, which allow each input vector to attract all prototypes. The strength of attraction between each input and the prototypes is determined by a set of membership functions, which can be selected on the basis of specific criteria. A gradient-descent-based learning rule is derived for a general class of admissible membership functions which satisfy certain properties. The FALVQ 1, FALVQ 2, and FALVQ 3 families of algorithms are developed by selecting admissible membership functions with different properties. The proposed algorithms are tested and evaluated using the IRIS data set. The efficiency of the proposed algorithms is also illustrated by their use in codebook design required for image compression based on vector quantization.  相似文献   

19.
JPEG-similar algorithms are proposed for compressing video information. These algorithms are based on the ART neural network that realizes the vector quantization operation. The results of modelling the proposed algorithms in the Matlab environment testify to the possibility of using them for image compression. These algorithms are shown to be good enough for images with recurrent segments. Translated from Kibernetika i Sistemnyi Analiz, No. 6, pp. 10–16, November–December 2008.  相似文献   

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