Face recognition under large illumination variations using homomorphic filtering in spatial domain

This paper proposes a homomorphic filtering in spatial domain for reducing of illumination effects in face recognition systems. Also, in this research a simple kernel of homomorphic filter is proposed. Application of this method causes considerable reduction in computational time in the preprocessing step. When a new face image with an arbitrary illumination is given, the homomorphic filter is applied and its reflectance component is extracted. Then the reflectance component is divided into several local regions and histograms of each local region are extracted using multi-resolution uniform local Gabor binary patterns (MULGBP). These histograms are combined for obtaining the overall histogram of the images. Finally, for face recognition, a simple histogram matching process is performed between new face image histogram and the gallery images histogram. The results show that the proposed method is robust for large illumination variation with a reasonable computational complexity.     

Textural feature based face recognition for single training images

A novel face recognition algorithm using single training face image is proposed. The algorithm is based on textural features extracted using the 2D log Gabor wavelet. These features are encoded into a binary pattern to form a face template which is used for matching. Experimental results show that on the colour FERET database the accuracy of the proposed algorithm is higher than the local feature analysis (LFA) and correlation filter (CF) based face recognition algorithms even when the number of training images is reduced to one. In comparison with recent single training image based face recognition algorithms, the proposed 2D log Gabor wavelet based algorithm shows an improvement of more than 3% in accuracy.     

基于直方图统计量的逆合成孔径雷达目标识别

将原用于人脸识别的基于Gabor局部二进制模式的识别技术用于逆合成孔径雷达(ISAR)像的雷达目标识别,对算法进行了改进,取得了较好的识别效果。将ISAR像进行Gabor小波变换,提取不同尺度和方向的Gabor幅值图谱;然后把幅值图谱分成小的子区域,用多尺度局部二值模式提取空域增强的直方图作为特征,最后在χ2统计量作为不相似度量计算的特征空间里,采用最近邻分类器完成五类目标的分类识别。与目前已有的几种典型ISAR目标识别方法进行了对比,结果表明:该方法是可行且有效的,能够明显地提高识别率。     

一种新颖的虹膜识别算法

虹膜识别通常包含虹膜定位、特征提取以及编码和识别几个关键步骤。本文提出的算法从建立虹膜灰度图像的直方图入手，分析虹膜边界的灰度阈值，依靠投票机制完成虹膜的定位；然后根据人眼的生理构造特点将虹膜分区，再对经过分区处理形成的虹膜纹理特征图像用一维连续Gabor复小波提取虹膜纹理特征点的相角信息；最后对相角信息以二比特格雷码实现一次编码和循环差分二次编码，利用特征多项式计算进行比较的两个虹膜的特征差异矩值(P_frfs)，根据判定阈值(P0)判定，最终实现虹膜识别。     

基于中心对称梯度幅值相位模式的单样本人脸识别

针对传统人脸识别算法在单训练样本情况下识别 效果不佳的问题,提出一种基于中心对称梯度幅值 相位模式(CSGMP)的单样本人脸识别算法。首先,提取人脸图像的梯度幅值和相位信息;然 后,用一种新 的中心对称局部方向模式(CSLDP)算子对梯度幅值进行编码,再将梯度相位量化到8个区间 进行编码,将 二者融合形成人脸图像的CSGMP特征;最后,分块统计直方图特征信息,将所有块的直方图 串联后作为 人脸图像的特征向量,利用最近邻分类器分类识别。在YALE和AR人脸库上进行测试的结果表 明,本文所提方 法简单有效,对光照变化、表情变化和部分遮挡等环境下单样本人脸识别具有较好的效果。     

基于ILDP的噪声鲁棒人脸识别

针对局部方向模式(LDP)采样不充分和对噪声敏感的缺点,提出了一种改进的LDP(ILDP)人脸描述方法,利用局部井型邻域的梯度信息描述人脸特征。首先,将中心像素的井型邻域根据采样半径分成两个3×3的子邻域,每个子邻域包含按照原来相对位置排列的8个像素;然后,将两个子邻域与Kirsch模板卷积分别得到两组边缘梯度值,ILDP仅使用两组梯度值中各自最大值的方向编码成一个二位八进制数,产生ILDP码;最后,在人脸描述阶段将人脸图像进行分块并把每块转换成ILDP图,再对ILDP图进行直方图统计,将所有子块的直方图连接生成人脸特征。实验结果表明,ILDP比其它同类基于局部纹理特征的单一人脸描述器在对抗随机噪声方面更具鲁棒性。     

Gabor字典及l0范数快速稀疏表示的人脸识别算法

针对光照、遮挡、伪装情况下,识别率比较低,识别时间长的问题,本文提出了基于Gabor字典及l0范数快速稀疏表示的人脸识别算法。Gabor小波提取的特征能够克服遮挡、光照等干扰对人脸识别的影响,平滑l0算法通过平滑连续函数来近似 l0范数,只需较少测量值并且较快速度便能重构稀疏信号。本算法通过提取人脸的Gabor特征、主成分分析法（PCA）降低维度,l0范数快速稀疏分类完成识别。在伪装人脸情况下,分块计算Gabor人脸特征,提高Gabor字典的形成速度。基于AR人脸数据库的实验结果表明,本算法可在一定程度上提高识别速度和识别时间,即使在小样本情况下,依然具有较高的识别率。      

基于形状无关纹理和Boosting学习的人口统计学分类

基于形状无关纹理和boosting学习,该文提出了对性别和年龄分类的方法,其中年龄被划分为儿童、青年、中年和老年4类。检测到人脸后,利用人脸配准的结果规范化人脸图像获得形状无关纹理。在此基础上提取Haar型特征、LBP直方图和Gabor Jet 3种特征,通过boosting学习分别训练分类器。实验表明,LBP直方图特征能够鲁棒地区分儿童和老人,Haar型特征用作区分青年和中年人则更为有效,而Gabor Jet特征更适于性别分类。     

Gabor wavelet representation for 3-D object recognition

This paper presents a model-based object recognition approach that uses a Gabor wavelet representation. The key idea is to use magnitude, phase, and frequency measures of the Gabor wavelet representation in an innovative flexible matching approach that can provide robust recognition. The Gabor grid, a topology-preserving map, efficiently encodes both signal energy and structural information of an object in a sparse multiresolution representation. The Gabor grid subsamples the Gabor wavelet decomposition of an object model and is deformed to allow the indexed object model match with similar representation obtained using image data. Flexible matching between the model and the image minimizes a cost function based on local similarity and geometric distortion of the Gabor grid. Grid erosion and repairing is performed whenever a collapsed grid, due to object occlusion, is detected. The results on infrared imagery are presented, where objects undergo rotation, translation, scale, occlusion, and aspect variations under changing environmental conditions.     

基于Gabor和PCA的面部图像识别方法

文中利用Gabor变换和PCA降维的优点,提出了Gabor+PCA的面部图像识别方法.该方法先提取图像的Gabor特征,然后将Gabor特征与原图像特征结合构成新的融合特征并用PCA降维,最后用KNN分类器分类.所提Gabor+PCA方法不仅能挖掘出图像的细节信息,而且拓宽了特征空间的维数.另外,Gabor+PCA方法...     

基于深度学习与特征融合的人脸识别算法

卷积神经网络在人脸识别研究上有较好的效果,但是其提取的人脸特征忽略了人脸的局部结构特征。针对此问题,文中提出一种基于深度学习与特征融合的人脸识别方法。该算法将局部二值模式信息与原图信息相结合作为SDFVGG网络的输入,使得提取的人脸特征更加丰富且更具表征能力。其中,SDFVGG网络是将VGG网络进行深浅特征相融合后的网络。在CAS-PEAL-R1人脸数据库上的实验表明,将网络深浅特征相融合与在卷积神经网络中加入LBP图像信息与原图信息相融合的特征信息对于提高人脸识别准确率非常有效,可得到优于传统算法和一般卷积神经网络的最高98.58%人脸识别率。     

Low-resolution expression recognition based on central oblique average CS-LBP with adaptive threshold

In order to solve the problem of low recognition rate of traditional feature extraction operators under low-resolution images, a novel algorithm of expression recognition is proposed, named central oblique average center-symmetric local binary pattern (CS-LBP) with adaptive threshold (ATCS-LBP). Firstly, the features of face images can be extracted by the proposed operator after pretreatment. Secondly, the obtained feature image is divided into blocks. Thirdly, the histogram of each block is computed independently and all histograms can be connected serially to create a final feature vector. Finally, expression classification is achieved by using support vector machine (SVM) classifier. Experimental results on Japanese female facial expression (JAFFE) database show that the proposed algorithm can achieve a recognition rate of 81.9% when the resolution is as low as 16×16, which is much better than that of the traditional feature extraction operators.     

基于LBP特征和贝叶斯模型的单样本人脸识别

针对单样本人脸识别这一人脸识别中的难点问题,提出了一种基于局部二元模式(LBP)直方图特征和贝叶斯(Bayes)模型的人脸识别方法.首先在独立的训练集上学习同类样本和异类样本的LBP直方图特征的相似度先验信息,估计同类和异类的类条件概率密度函数,在识别过程中利用一对图像的LBP直方图相似度计算该对图像属于同一类的后验概...     

面向语音情感识别的Gabor分块局部二值模式特征

谱特征在语音情感识别中起到了重要的作用,然而现有的谱特征仍未能充分表达谱图中的语音情感信息.为研究语音情感与谱图之间的联系,提出了一种面向语音情感识别的Gabor分块局部二值模式特征（GBLBP）。首先,获取情感语音的对数能量谱;然后,采用多尺度,多方向的Gabor小波对对数能量谱进行处理,得到Gabor谱图;再次,对每张Gabor谱图进行分块,采用局部二值模式提取每个块的局部能量分布信息;最后,将提取到的所有特征级联,得到GBLBP特征。Berlin库上的实验结果表明:GBLBP特征的平均加权召回率比MFCC高了9%,识别性能显著优于众多谱特征,且与现有声学特征有较好的融合性。