Design of vector quantizer for image compression using self-organizing feature map and surface fitting

We propose a new scheme of designing a vector quantizer for image compression. First, a set of codevectors is generated using the self-organizing feature map algorithm. Then, the set of blocks associated with each code vector is modeled by a cubic surface for better perceptual fidelity of the reconstructed images. Mean-removed vectors from a set of training images is used for the construction of a generic codebook. Further, Huffman coding of the indices generated by the encoder and the difference-coded mean values of the blocks are used to achieve better compression ratio. We proposed two indices for quantitative assessment of the psychovisual quality (blocking effect) of the reconstructed image. Our experiments on several training and test images demonstrate that the proposed scheme can produce reconstructed images of good quality while achieving compression at low bit rates. Index Terms-Cubic surface fitting, generic codebook, image compression, self-organizing feature map, vector quantization.     

基于FMCW雷达的人体复杂动作识别

针对利用摄像机进行人体动作识别时易受视距和光线影响等问题,提出一种基于FMCW雷达的人体复杂动作识别方案。首先基于FMCW信号模型对雷达采样数据采用一种以RDM（Range Doppler Map）向速度维投影的方式逐帧构建微多普勒谱图,继而基于微多普勒谱图来提取用于表征整个动作频谱相关信息的8种特征矢量。最后,基于雷达实测数据,以贝叶斯超参数调整优化后的支持向量机作为分类器,分析利用所提取的单特征矢量以及特征矢量组合来进行分类时对分类准确率的影响,用以筛选最优异的特征矢量组合。实验结果表明,从微多普勒谱图中所提取的特征矢量皆可直观地表述整个动作过程的特性,且利用最终筛选得到的最优异的特征矢量组合对已知个体和未知个体的9种动作进行识别,识别准确率分别高达99.07%和96.76%。     

基于数据挖掘技术的网络热门舆情分类研究

以提升网络热门舆情分类准确率,降低分类时间为目标,提出了基于数据挖掘技术的网络热门舆情分类方法.将小波核函数和支持向量机结合构成小波模糊支持向量机,采用增量学习机制和贝叶斯分类算法建立增量贝叶斯分类算法,组成小波模糊支持向量机-增量贝叶斯分类算法解决测试样本易分类失误以及类条件独立假定性很难获取问题,通过计算待测样本和...     

Learning from Examples with Information Theoretic Criteria

This paper discusses a framework for learning based on information theoretic criteria. A novel algorithm based on Renyi's quadratic entropy is used to train, directly from a data set, linear or nonlinear mappers for entropy maximization or minimization. We provide an intriguing analogy between the computation and an information potential measuring the interactions among the data samples. We also propose two approximations to the Kulback-Leibler divergence based on quadratic distances (Cauchy-Schwartz inequality and Euclidean distance). These distances can still be computed using the information potential. We test the newly proposed distances in blind source separation (unsupervised learning) and in feature extraction for classification (supervised learning). In blind source separation our algorithm is capable of separating instantaneously mixed sources, and for classification the performance of our classifier is comparable to the support vector machines (SVMs).     

基于ADE的ReliefF特征选择在高光谱图像分类中的应用

针对高光谱图像谱段数目较多、近邻谱段相关性过高而导致分类困难的问题,提出了一种自适应差分进化特征选择的高光谱图像分类算法.首先初始化种群向量集,利用自适应差分进化算法搜索特征的自适应性生成特征子集;然后,通过使用ReliefF技术根据特征排序去除重复特征,从而为所有的特征构建一个特征列表;最后,借助于模糊k-近邻分类器计算每个向量的分类精度,利用包裹模型评估特征子集.在印第安纳数据集和KSC数据集上的实验结果验证了算法的有效性及可靠性,实验结果表明,相比其他几种特征选择算法,该算法取得了更高的总分类精度和更好的Kappa系数.     

Novel fuzzy reinforced learning vector quantisation algorithm and its application in image compression

A new approach to the design of optimised codebooks using vector quantisation (VQ) is presented. A strategy of reinforced learning (RL) is proposed which exploits the advantages offered by fuzzy clustering algorithms, competitive learning and knowledge of training vector and codevector configurations. Results are compared with the performance of the generalised Lloyd algorithm (GLA) and the fuzzy K-means (FKM) algorithm. It has been found that the proposed algorithm, fuzzy reinforced learning vector quantisation (FRLVQ), yields an improved quality of codebook design in an image compression application when FRLVQ is used as a pre-process. The investigations have also indicated that RL is insensitive to the selection of both the initial codebook and a learning rate control parameter, which is the only additional parameter introduced by RL from the standard FKM     

Image compression based on fuzzy algorithms for learning vectorquantization and wavelet image decomposition

This paper evaluates the performance of an image compression system based on wavelet-based subband decomposition and vector quantization. The images are decomposed using wavelet filters into a set of subbands with different resolutions corresponding to different frequency bands. The resulting subbands are vector quantized using the Linde-Buzo-Gray (1980) algorithm and various fuzzy algorithms for learning vector quantization (FALVQ). These algorithms perform vector quantization by updating all prototypes of a competitive neural network through an unsupervised learning process. The quality of the multiresolution codebooks designed by these algorithms is measured on the reconstructed images belonging to the training set used for multiresolution codebook design and the reconstructed images from a testing set.     

一种基于局部排序的约束稀疏编码的图像分类方法

图像分类作为计算机视觉分析领域一个重要的研究方向,其分类性能很大程度上取决于图像的特征表示.为了能够更好地进行图像分类,本文提出了一种基于局部约束稀疏编码的神经气算法（Neural Gas based Locality-constrained Sparse Coding,NGLSC）用来实现图像分类.引入局部排序适配器作为距离正则化约束项已经应用在神经气（Neural Gas,NG）的算法矢量量化中,旨在通过软竞争学习算法来弥补K均值聚类（K-means）算法的不足.在稀疏编码阶段此算法可求解得到封闭解.此外,字典更新一般由目标函数的误差项来决定,已有一些经典的算法采用这种方式更新字典.本文使用ORL数据库和COIL20数据库将所提出算法和现有算法局部约束线性编码（Locality-constrained Linear Coding,LLC）,脸元数据学习方法（Metaface Learning,MFL）进行比较.实验结果证明本文所提出的算法在图像分类上准确率可达95%以上.可以看出,本文为计算机视觉图像分类工作提供了一种有价值的解决思路.     

基于K-medoids聚类的贝叶斯集成算法

朴素贝叶斯分类算法由于其计算高效在生活中应用广泛。本文根据集成算法的差异性特征,聚类算法聚类点的选择方式的可变性,提出了基于K-medoids聚类技术的贝叶斯集成算法,朴素贝叶斯的泛化性能得到了提升。首先,通过样本集训练出多个朴素贝叶斯基分类器模型;然后,为了增大基分类器之间的差异性,利用K-medoids算法对基分类器在验证集上的预测结果进行聚类;最后,从每个聚类簇中选择泛化性能最佳的基分类器进行集成学习,最终结果由简单投票法得出。将该算法应用于UCI数据集,并与其他类似算法进行比较可得,本文提出的基于K-medoids聚类的贝叶斯集成算法(NBKME)提高了数据集的分类准确率。     

Novel ECG Signal Classification Based on KICA Nonlinear Feature Extraction

Electrocardiogram (ECG) signal feature extraction is important in diagnosing cardiovascular diseases. This paper presents a new method for nonlinear feature extraction of ECG signals by combining principal component analysis (PCA) and kernel independent component analysis (KICA). The proposed method first uses PCA to decrease the dimensions of the ECG signal training set and then employs KICA to calculate the feature space for extracting the nonlinear features. Support vector machine (SVM) is utilized to determine the nonlinear features of the ECG signal classification. Genetic algorithm is also used to optimize the SVM parameters. The proposed method is advantageous because it does not require a huge amount of sampling data, and this technique is better than traditional strategies to select optimal features in the multi-domain feature space. Computer simulations reveal that the proposed method yields more satisfactory classification results on the MIT–BIH arrhythmia database, reaching an overall accuracy of 97.78 %.     

模糊增强学习码书设计算法及其在图像编码中的应用

本文提出一种用于图像压缩编码的模糊增强学习码书设计算法。该算法是在模糊竞争学习矢量量化的基础上引入增强学习,并用输入训练模式的监督信号与类别模式之间的隶属度控制增强信号。实验结果表明,该算法对初始码本依赖性小,与模糊竞争学习矢量量化和微分竞争学习算法相比,收敛速度更快,性能更好。     

电子封装常用名称及术语汇集

电子封装常用名称及术语汇集下面，按英文字母顺序，汇集并解释了与目前ＬＳＩ（包括ＩＣ）正在采用的主要封装形式相关联的名称术语等。这些名称术语参考并引用了日本国内１２个半导体制造公司，其他国家７个半导体制造公司＊与ＬＳＩ封装相关的资料、日本电子机械工业会...     

高斯过程模型在SAR图像目标识别中的应用

将高斯过程模型应用于合成孔径雷达（SAR）图像目标识别。高斯过程模型是基于贝叶斯框架的统计学习算法,通过结合核函数和和概率判别构建分类模型。与传统分类模型相比,高斯过程模型可以获得更高的分类效率和精度。方法实施过程中,采用SAR图像的特征矢量作为输入,以目标类别标签作为输出训练高斯过程模型。对于待识别样本,通过计算其在高斯过程模型下属于各个类别的后验概率判定其目标类别。实验中,依托MSTAR数据集在典型条件下开展测试。根据实验结果,所提方法在标准操作条件下对10类目标识别精度达到99.28%;在30°和45°俯仰角下的平均识别率分别为98.04%和73.13%;在噪声干扰各个信噪比条件下均保持最高性能。实验结果验证了所提方法的有效性和稳健性。     

样本限制场景下金属板带材表面缺陷分类研究

深度学习在金属板带材表面缺陷检测中取得良好的检测效果,但随着网络层数的增加 ,针对较小样 本的金属板带材表面缺陷数据集训练数据容易出现过拟合现象的问题,为此将残差网络与迁 移学习结合提出 了一种融合多层次缺陷特征的图像分类算法。该算法采用残差网络模块逐层提取金属表面缺 陷特征,获得丰 富的位置信息和语义信息缺陷特征的特征图,后续利用分类网络基于该融合特征图得到最终 分类结果,同时 对特征提取网络进行迁移学习,增加网络泛化能力,优化分类精度。利用钢带表面缺陷检测 数据集评估本文 算法性能,实验结果表明,提出的算法具有较好的分类效果,优于其他缺陷分类算法,分类 准确率可达到 99.07%,同时本文所提算法具有良好的抗噪性和泛化性,在金属板带材表面缺陷智能检测中 具有较好的应用价值。     

Codebook Design for Vector Quantization Based on?a?Kernel Fuzzy Learning Algorithm

Vector quantization (VQ) is an efficient technique for data compression and has been successfully used in various applications. The methods most commonly used to generate a codebook are the Linde, Buzo, Gray (LBG) algorithm, fuzzy vector quantization (FVQ) algorithm, Kekre‘s Fast Codebook Generation (KFCG) algorithm, discrete cosine transform based (DCT-based) codebook generation method, and k-principle component analysis (K-PCA) algorithm. However, if the separation boundaries in codebook generation are nonlinear, their performance can degrade fast. In this paper, we present a kernel fuzzy learning (KFL) algorithm, which takes advantages of the distance kernel trick and the gradient-based fuzzy clustering method, to create a codebook automatically. Experiments with real data show that the proposed algorithm is more efficient in its performance compared to that of the LBG, FVQ, KFCG, and DCT-based method, and to the K-PCA algorithm.     

心音信号MFCC特征向量提取方法的优化

为了提高利用梅尔频率倒谱系数（Mel-Frequency Cepstral Coefficients, MFCC）特征向量进行心音信号分类的准确率，本文提出以一种基于独立成分分析（Independent Component Analysis, ICA）及权值优化的MFCC特征向量优化方法。首先，通过消除趋势项、降噪、提取心动周期与基础心音分割等步骤对心音信号预处理；接着，对提取的基础心音信号做Mel频谱变换及倒谱分析提取MFCC特征向量，其中用ICA替代离散余弦变换去除分量间高阶量的相关性，同时采用相关系数为权值优化整体混合矩阵；最后，采用F比衡量特征向量贡献率，并以其为权值优化各维特征向量。通过提取MFCC特征向量采用支持向量机（Support Vector Machine, SVM）的分类器识别第一心音及第二心音，并与人工标注心音状态集进行对比。实验结果表明，基于ICA及权值优化的MFCC特征向量在SVM分类器中识别率得到了有效的提升，且优化算法具备一定抗噪性能。      

鲁棒视觉词汇本的自适应构造与自然场景分类应用

该文提出了一种视觉词汇本的优化构造策略。首先引入条件数定量评估海量低层特征的稳定性,排除病态特征,筛选稳定的鲁棒视觉特征;通过分析聚类和降维的内在联系,构造了具有聚类结构的视觉特征自适应降维算法;进而利用低维聚类结构信息中的邻域支持度,自适应选取最佳的初始视觉词汇,同时选择Sil指标作为目标函数,从而改进流行的LBG词汇本生成算法敏感于初始点的随机选取,并只能得到局部最优等不足。新的视觉词汇本生成算法具有聚类和降维的统一计算功能、良好的鲁棒性和自适应优化等特性。基于概率潜在语义分析技术将该文的视觉词汇本应用于自然场景分类,在13类场景图像库上取得了73.46%的平均分类率。     

Image classification for content-based indexing

Grouping images into (semantically) meaningful categories using low-level visual features is a challenging and important problem in content-based image retrieval. Using binary Bayesian classifiers, we attempt to capture high-level concepts from low-level image features under the constraint that the test image does belong to one of the classes. Specifically, we consider the hierarchical classification of vacation images; at the highest level, images are classified as indoor or outdoor; outdoor images are further classified as city or landscape; finally, a subset of landscape images is classified into sunset, forest, and mountain classes. We demonstrate that a small vector quantizer (whose optimal size is selected using a modified MDL criterion) can be used to model the class-conditional densities of the features, required by the Bayesian methodology. The classifiers have been designed and evaluated on a database of 6931 vacation photographs. Our system achieved a classification accuracy of 90.5% for indoor/outdoor, 95.3% for city/landscape, 96.6% for sunset/forest and mountain, and 96% for forest/mountain classification problems. We further develop a learning method to incrementally train the classifiers as additional data become available. We also show preliminary results for feature reduction using clustering techniques. Our goal is to combine multiple two-class classifiers into a single hierarchical classifier.     

基于特征重要性的高光谱图像分类

为了减少高光谱图像中的冗余以及进一步挖掘潜在的分类信息,本文提出了一种基于特征重要性的卷积神经网络（convolutional neural networks,CNN）分类模型。首先,利用贝叶斯优化训练得到的随机森林模型（random forest,RF）对高光谱遥感图像进行特征重要性评估;其次,依据评估结果选择合适数目的高光谱图像波段,以作为新的训练样本;最后,利用三维卷积神经网络对所得样本进行特征提取并分类。基于两个实测的高光谱遥感图像数据,实验结果均表明:相比原始光谱信息直接采用支持向量机（support vector machine,SVM）和卷积神经网络的分类效果,本文所提基于特征重要性的高光谱分类模型能够在降维的同时有效提高高光谱图像的分类精度。