一种新的掌纹特征提取方法研究

提出一种基于Gabor小波和改进的广义K-L变换的掌纹识别方法。该方法首先对测试样本的掌纹ROI灰度图像进行Gabor小波变换,得到其Gabor特征向量,然后利用改进的广义K-L变换方法将高维特征向量变换到低维空间,最后将得到的低维特征向量利用欧氏距离法与训练样本库中的特征向量作匹配识别。该方法首次将基于时频变换的特征提取算法与基于子空间的特征提取算法结合起来,既充分利用了Gabor函数优良的特征提取性能,又有效解决了高维特征的降维处理问题。通过使用自行采集的数据库对该方法作对比实验,获得了94%的识别率     

Robust palmprint identification based on directional representations and compressed sensing

In this paper, we propose a novel approach for palmprint recognition, which contains two interesting components: directional representation and compressed sensing. Gabor wavelets can be well represented for biometric image for their similar characteristics to human visual system. However, these Gabor-based algorithms are not robust for image recognition under non-uniform illumination and suffer from the heavy computational burden. To improve the recognition performance under the low quality conditions with a fast operation speed, we propose novel palmprint recognition approach using directional representations. Firstly, the directional representation for palmprint appearance is obtained by the anisotropy filter, which is robust to drastic illumination changes and preserves important discriminative information. Then, the principal component analysis (PCA) is used for feature extraction to reduce the dimensions of the palmprint images. At last, based on a sparse representation on PCA feature, the compressed sensing is used to distinguish palms from different hands. Experimental results on the PolyU palmprint database show the proposed algorithm have better performance than that of the Gabor based methods.     

基于Gabor局部相对特征的掌纹识别

Gabor变换是掌纹识别中提取纹理特征的一个重要工具,但其性能易受图像的变化以及不均衡噪声等因素影响,因此提出了一种基于Gabor局部相对特征的掌纹识别算法。该算法对原始图像进行微尺度不变Gabor滤波;结合分形学的思想,将滤波后的图像分成大小相等的子域,每个子域又分成多个相同的子块,计算每个子块与它所在子域的相对方差,将所有子块的相对方差排列组成表征图像的特征向量进行识别。该算法将微尺度不变与局部相对特性统一,所提取的特征对各种变化有很强的鲁棒性,提高了识别精度和效率。实验使用北京交通大学BJTU_PalmprintDB证明该算法的有效性。     

基于GIDBC的掌纹识别算法研究

针对采用分形维数作为特征描述掌纹信息不准确的问题,对差分盒子维进行改进提高特征区分性.此外,由于采用单一的特征不足以描述掌纹纹理,引入Gabor变换,提出一种基于Gabor变换与改进差分盒子维(GIDBC,Gabor improved differential box counting)相结合的掌纹识别算法.通过在PolyU掌纹图像库上实验,与传统高性能算法比较,本算法识别率最高可达到99.78％,表明了本文方法的有效性,同时特征提取与匹配时间为338 ms,满足实时性要求.     

基于安全概略的可撤销掌纹模板生成算法

为了有效改进掌纹模板生成算法的识别率和安全性等性能,提出一种基于安全概略的可撤销掌纹模板生成算法。首先提取掌纹图像不同方向、不同尺度的Gabor幅值特征,并通过主成分分析（PCA）算法对其进行降维;然后将加密后的特征向量与BCH码异或融合,得到基于安全概略的可撤销掌纹模板。对比实验表明,该算法具有良好的识别性能,能较好地满足可撤销性、多样性和不可逆性,即便在单密钥丢失的情况下,也具有较高的识别率。     

混合粒子群优化算法优化前向神经网络结构和参数*

提出了综合利用粒子群优化算法（PSO）和离散粒子群优化算法（D-PSO）同时优化前向神经网络结构和参数的新方法。该算法使用离散粒子群优化算法优化神经网络连接结构,用多维空间中0或1取值的粒子来描述所有可能的神经网络连接,同时使用粒子群优化算法优化神经网络权值。将经过该算法训练的神经网络应用于故障诊断,能够有效消除冗余连接结构对网络诊断能力的影响。仿真试验的结果表明,相比遗传算法等其他算法,该算法能够有效改善神经网络结构和参数的优化效率,提高故障模式识别的准确率。     

Implementation of hybrid ANN–PSO algorithm on FPGA for harmonic estimation

Harmonic estimation is the main process in active filters for harmonic reduction. A hybrid Adaptive Neural Network–Particle Swarm Optimization (ANN–PSO) algorithm is being proposed for harmonic isolation. Originally Fourier Transformation is used to analyze a distorted wave. In order to improve the convergence rate and processing speed an Adaptive Neural Network Algorithm called Adaline has then been used. A further improvement has been provided to reduce the error and increase the fineness of harmonic isolation by combining PSO algorithm with Adaline algorithm. The inertia weight factor of PSO is combined along with the weight factor of Adaline and trained in Neural Network environment for better results. ANN–PSO provides uniform convergence with the convergence rate comparable that of Adaline algorithm. The proposed ANN–PSO algorithm is implemented on an FPGA. To validate the performance of ANN–PSO; results are compared with Adaline algorithm and presented herein.     

Orientation selection using modified FCM for competitive code-based palmprint recognition

Coding-based methods are among the most promising palmprint recognition methods because of their small feature size, fast matching speed and high verification accuracy. The competitive coding scheme, one representative coding-based method, first convolves the palmprint image with a bank of Gabor filters with different orientations and then encodes the dominant orientation into its bitwise representation. Despite the effectiveness of competitive coding, few investigations have been given to study the influence of the number of Gabor filters and the orientation of each Gabor filter. In this paper, based on the statistical orientation distribution and the orientation separation characteristics, we propose a modified fuzzy C-means cluster algorithm to determine the orientation of each Gabor filter. Since the statistical orientation distribution is based on a set of real palmprint images, the proposed method is more suitable for palmprint recognition. Experimental results indicate that the proposed method achieves higher verification accuracy while compared with that of the original competitive coding scheme and several state-of-the-art methods, such as ordinal measure and RLOC. Considering both the computational complexity and the verification accuracy, competitive code with six orientations would be the optimal choice for palmprint recognition.     

基于LGBP与Bloom滤波器的可撤销掌纹模板生成方法

为了实现对用户生物特征信息的有效保护,提高掌纹身份认证系统的安全性,提出一种掌纹可撤销模板生成方法。首先通过Gabor滤波器获得掌纹数据不同方向、不同尺度的幅值特征,对其提取局部均匀模式LBP特征,然后将二值化的特征直方图序列使用Bloom滤波器进行多对一映射,最后进行不可逆变换,得到可撤销掌纹模板。理论分析和实验结果表明,该方法不仅可以有效保护掌纹特征,而且在密钥丢失时,也具有较高的识别率。     

基于移动设备的掌纹验证系统

针对掌纹识别在智能移动设备上的应用,提出一种掌纹识别算法,并嵌入到联想ET980智能手机,开发基于移动设备的掌纹验证系统。以新的方式采集掌纹图像并给出相应的预处理算法。使用优化的Gabor判别方法提取掌纹特征,减少特征提取的时间。系统验证一张掌纹图像的时间小于1 s,同时可获得EER=3.89%的识别精度,满足验证系统的实时性和精度要求。     

Artificial Neural Network trained by Particle Swarm Optimization for non-linear channel equalization

In this paper, we apply Artificial Neural Network (ANN) trained with Particle Swarm Optimization (PSO) for the problem of channel equalization. Existing applications of PSO to Artificial Neural Networks (ANN) training have only been used to find optimal weights of the network. Novelty in this paper is that it also takes care of appropriate network topology and transfer functions of the neuron. The PSO algorithm optimizes all the variables, and hence network weights and network parameters. Hence, this paper makes use of PSO to optimize the number of layers, input and hidden neurons, the type of transfer functions etc. This paper focuses on optimizing the weights, transfer function, and topology of an ANN constructed for channel equalization. Extensive simulations presented in this paper shows that, as compared to other ANN based equalizers as well as Neuro-fuzzy equalizers, the proposed equalizer performs better in all noise conditions.     

基于Gabor滤波器与LDP掌纹可撤销模板生成方法

针对掌纹身份认证中存在着识别率和安全性较差的问题,提出一种基于多方向的Gabor滤波和局部方向模式（Local Directional Pattern,LDP）的自适应阈值特征编码方法mLGDP,在此基础上,进一步提出一种基于多方向Gabor滤波和LDP方法的自适应阈值差值特征编码方法mDLGDP,并将这两种方法的特征相融合,有效增强了原有掌纹模板间的多样性和识别率。通过对图像的特征编码进行分块处理,提取特征向量并二值化,再采用Bloom滤波器实现多对一映射和对掌纹图像的位置置乱,将得到置乱结果矩阵和用户密钥通过卷积运算进行不可逆变换,最终获得掌纹图像的可撤销模板。理论分析和实验表明,即使在密钥丢失时,分别使用两种改进方法依然可以保持较高的识别率,当使用两种特征相融合的方法时,识别率能够得到有效提高,且具有更好的安全性。     

Online palmprint identification

Biometrics-based personal identification is regarded as an effective method for automatically recognizing, with a high confidence, a person's identity. This paper presents a new biometric approach to online personal identification using palmprint technology. In contrast to the existing methods, our online palmprint identification system employs low-resolution palmprint images to achieve effective personal identification. The system consists of two parts: a novel device for online palmprint image acquisition and an efficient algorithm for fast palmprint recognition. A robust image coordinate system is defined to facilitate image alignment for feature extraction. In addition, a 2D Gabor phase encoding scheme is proposed for palmprint feature extraction and representation. The experimental results demonstrate the feasibility of the proposed system.     

基于实值Gabor变换的掌纹识别

掌纹识别作为一种重要的生物特征识别方法,其中的一个重要环节就是掌纹特征的提取,本文提出了一种基于实数形式离散Gabor变换的掌纹特征提取方法,将空域的掌纹图像变换到联合（时间）空间频率域并将其联合（时间）空间频率域的能量分布作为掌纹的特征,以此为基础分别使用欧式距离和支持向量机进行了不同掌纹的匹配识别。实验结果表明,该算法对掌纹图像小的平移、小角度的旋转和小的手掌伸缩具有鲁棒性,并且获得了较高的识别率。     

基于Gabor+PCA特征与粒子群算法的部分遮挡人耳识别研究

在分析人耳Gabor特征基础上,提出一种主成分分析降维并利用基于粒子群优化训练的人工神经网络对部分遮挡人耳进行识别方法。选取了PCA方法降维后人耳图像的Gabor特征值作为人工神经网络训练样本,利用粒子群优化算法与多层前馈网络结合算法训练神经网络。与多种方法对比的实验表明,针对部分遮挡人耳的测试实验,基于Gabor+PCA特征与粒子群算法的部分遮挡人耳识别方法具有高识别性能,取得好的效果。     

基于Gabor小波变换和最佳鉴别特征的掌纹识别

提出了一种提取掌纹图像特征的方法,该方法的实现过程如下：首先,计算掌纹图像上均布离散位置的二维Gabor小波变换系数的幅值,将其作为掌纹图像的原始特征;其次,利用主分量分析实现Gabor小波特征的降维;最后,通过线性判别分析提取最有利于分类的最佳鉴别特征。实验结果表明了该方法的有效性。     

应用非负矩阵分解和RBPNN模型的掌纹识别方法

提出一种基于非负矩阵分解（NMF）和径向基概率神经网络的掌纹识别方法。NFM是一种有效的图像局部特征提取算法,用于图像分类时能得到较高的识别率。考虑PolyU掌纹图像数据库,应用NMF、局部NMF（LNMF）、稀疏NMF（SNMF）和具有稀疏度约束的NMF（NMFSC）算法分别对掌纹图像进行特征提取,并对提取到的局部特征基图像进行分析对比;在特征提取的基础上,应用径向基概率神经网络（RBPNN）模型对掌纹特征进行分类,分类结果表明了RBPNN模型对掌纹特征具有较好的识别能力。实验对比结果证明了基于RBPNN的NMF掌纹识别方法在掌纹识别中的有效性,具有一定的理论研究意义和实用性。     

Neural network classifier optimization using Differential Evolution with Global Information and Back Propagation algorithm for clinical datasets

A Computer-Aided Diagnostic (CAD) system that uses Artificial Neural Network (ANN) trained by drawing in the relative advantages of Differential Evolution (DE), Particle Swarm Optimization (PSO) and gradient descent based backpropagation (BP) for classifying clinical datasets is proposed. The DE algorithm with a modified best mutation operation is used to enhance the search exploration of PSO. The ANN is trained using PSO and the global best value obtained is used as a seed by the BP. Local search is performed using BP, in which the weights of the Neural Network (NN) are adjusted to obtain an optimal set of NN weights. Three benchmark clinical datasets namely, Pima Indian Diabetes, Wisconsin Breast Cancer and Cleveland Heart Disease, obtained from the University of California Irvine (UCI) machine learning repository have been used. The performance of the trained neural network classifier proposed in this work is compared with the existing gradient descent backpropagation, differential evolution with backpropagation and particle swarm optimization with gradient descent backpropagation algorithms. The experimental results show that DEGI-BP provides 85.71% accuracy for diabetes, 98.52% for breast cancer and 86.66% for heart disease datasets. This CAD system can be used by junior clinicians as an aid for medical decision support.     

加权自适应CS-LBP与局部判别映射相结合的掌纹识别方法

提取掌纹的最佳低维分类特征一直是掌纹识别研究领域的一个重要方向。针对掌纹图像具有丰富的纹理特征特点,提出一种基于加权自适应中心对称局部二值模式(WACS-LBP)与局部判别映射(LDP)相结合的掌纹识别方法。首先将掌纹感兴趣(ROI)图像分成大小均匀的小区域,利用自适应中心对称局部二值模式(ACS-LBP)算法获取不同区域的纹理特征直方图和权值,经过加权连接得到ROI的加权纹理特征直方图向量;再利用LDP算法对得到的特征向量进行维数约简;最后利用K-最近邻分类器进行掌纹识别。在掌纹公开数据库上进行实验,正确识别率高达97%以上。实验结果表明,该方法不仅是有效、可行的,而且研究思路比较明确。     

Development of a hybrid PSO–ANN model for estimating glucose and xylose yields for microwave-assisted pretreatment and the enzymatic hydrolysis of lignocellulosic biomass

In this paper, two artificial intelligent systems, the artificial neural network (ANN) and particle swarm optimization (PSO), were combined to form a hybrid PSO–ANN model that was used to improve estimates of glucose and xylose yields from the microwave–acid pretreatment and enzymatic hydrolysis of lignocellulosic biomass based on pretreatment parameters. ANN is a powerful tool capable of determining the relationship between the desired input and output data while PSO was used as a robust population-based search algorithm to optimize the performance of the ANN model. Specifically, it was used to determine the optimum number of neurons in the hidden layer and the best value of the learning rate of the ANN model. The optimization method includes minimizing the fitness function mean absolute error that was found to be 0.0176. The PSO algorithm suggested an optimum number of neurons in the hidden layer as 15 and a learning rate of 0.761 these consequently used to construct the ANN model. After constructing the hybrid PSO–ANN model, the performance of the intelligent system was examined by determining the regression coefficient (R ²) for estimating the experimental values of glucose and xylose and compared to the results from a response surface methodology (RSM) model. The results of R ² of the hybrid PSO–ANN model for glucose and xylose were 0.9939 and 0.9479, respectively, while the RSM model results for the same sugars were 0.8901 and 0.8439. This analysis reveals that the hybrid PSO–ANN model offers a higher degree of accuracy in comparison with the more commonly used RSM model.