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1.
本文设计了一种基于BP神经网络的人脸识别系统,并对其进行了性能分析.该系统首先利用离散小波变换获取包含人脸图像大部分原始信息的低频分量,对图像数据进行降维;再由PCA算法对人脸图像进行主成分特征提取,进一步降低图像数据的处理量;最后使用经过训练后的BP神经网络对待测人脸进行分类识别.详细介绍了离散小波变换、PCA特征提取以及BP神经网络分类设计.通过系统仿真实验与分析发现:人脸特征的提取是该系统的关键;同时,由于人脸灰度信息的统计特征与有监督训练BP神经网络分类器,使该系统只在固定类别,并且光照均匀的人脸识别应用场景中具有较高的识别准确率.因此,很难在复杂环境中应用.  相似文献   

2.
针对人脸在非均匀光照下识别率的降低,提出了拉普拉斯滤波和离散余弦变换(DCT)融合梯度方向直方图(HOG)人脸识别算法。首先通过拉普拉斯滤波对人脸图像进行处理,突出其纹理特征,其次进行离散余弦变换(DCT),有效滤除高频分量,然后利用离散余弦逆变换(IDCT)重建人脸图像,降低其维数,最后通过梯度方向直方图(HOG)算子提取人脸图像固有特征,并利用最近邻方法进行分类识别。实验结果表明,该算法在不同特征维数下的Yale B人脸数据库中识别率高达95%以及课题组自建的维吾尔族人脸数据库中其识别率高达98.5%,优于其他传统算法?具有很强的鲁棒性和实时性。  相似文献   

3.
基于DWT,2DPCA和KPCA的人脸识别   总被引:1,自引:0,他引:1  
利用离散小波变换对人脸图像进行压缩,提取人脸的低频分量,有效去除人脸图像高频分量的影响;再利用二维主元分析对小波变换后的人脸低频分量实行提取特征;然后使用核主元分析再次提取特征;最后用最小距离分类器完成人脸识别.基于ORL人脸数据库的实验结果表明,该算法能提高人脸识别率,有效减少计算量和降低计算复杂度.  相似文献   

4.
《信息技术》2017,(6):155-158
提出了一种基于离散小波变换、主成分分析和余弦相似度分类器的人脸识别方法。首先对图像进行二维离散小波变换,得到近似分量以及水平、垂直和对角细节分量,然后对每幅图像进行二维主成分特征提取。最后,使用余弦分类器对4种特征进行分类并融合得出最终结果。实验表明,此方法准确率要优于单一的二维主成分分析,且余弦相似度分类器拥有比欧几里得距离更好的分类效果。  相似文献   

5.
为了实现对具有不同光照、姿势和噪声的人脸进行识别并提高识别精度,设计了一种基于离散小波变换和最小二乘支持向量机的人脸识别方法。首先,采用二维离散小波变换对人脸图像进行压缩和降噪,以提取低频特征信息分量,然后采用快速独立成分分析法ICA对经过离散小波变换后的人脸低频分量进行特征提取,以进一步减少人脸特征向量维数。在获取图像特征向量的基础上,采用径向基函数作为核函数,将训练样本数据输入最小二乘支持向量机进行训练以获得最终的分类模型。在ORL数据库下采用MATLAB仿真工具进行仿真,实验结果表明,该方法能有效地实现对人脸识别,与其他方法相比具有较高的识别精度。  相似文献   

6.
具有学习功能的自动人脸识别   总被引:1,自引:1,他引:0  
人脸识别是模式识别领域中一个相当困难而又有理论意义和实际价值的研究课题。传统的基于K-L变换的自动人脸识别方法,不用过多地考虑人脸的局部特征,利用特征脸方法进行识别,取得了一定的。但是,人脸作为一个特殊的场景,脸像会受年龄、心情、拍摄角度、光照条件、发饰等因素影响,所成图像存在差异。传统的基于K-L变换的自动人脸识别方法不能很好地克服这些畸变的影响。文中就主成分分析方法引入人脸识别,模拟人脸脸像的各种变化,事先对脸像做相应的变化,产生一系列变形脸。然后对变形脸进行主成分分析,提取它们的主成分。最后应用遗传算法选择最优特征向量构造子空间,提出一种能抗御一定脸像变化的人脸识别方法,并运用该方法进行了实验。实验结果证明了该方法的可行性和良好的抗畸变能力。  相似文献   

7.
为改善复杂光照条件下的多姿状鲁棒性人脸识别的效果,提出了小波变换与LBP的多姿状鲁棒性人脸识别方法。通过二维离散小波变换对人脸图像进行二级小波分解提取到低频特征信息分量,并以重构初始图像的方式实现降噪滤波处理,滤除低频光照分量后完成复杂光照补偿;继续分解复杂光照补偿后的图像,采用LBP算子对子图像的鲁棒性部分纹理特征进行描述后,提取出人脸图像各子图像的直方图特征并连接,得到人脸LBP纹理特征,通过统计法运算该特征距离,并通过K近邻分类器实现人脸特征分类识别。以Yale-B与AR人脸库为测试对象,结果表明,所研究方法对复杂光照鲁棒性较强,识别人脸的准确率与效率较高,整体识别效果较好。  相似文献   

8.
戴鸿宇 《信息技术》2014,(4):180-184
结合几种现有的人脸识别特征提取算法,先对人脸图像进行小波分解去噪;然后通过离散余弦变换对低频分量作进一步特征提取和压缩,保留人脸图像中对光照、姿态、表情变化不敏感的识别信息;接着利用PCA和LDA相结合得到最终的识别特征,最后采用欧式距离和最近邻分类器识别人脸。实验采用ORL标准人脸库验证了这种组合的有效性。  相似文献   

9.
结合几种现有的人脸识别特征提取算法,先对人脸图像进行小波分解去噪;然后通过离散余弦变换对低频分量作进一步特征提取和压缩,保留人脸图像中对光照、姿态、表情变化不敏感的识别信息;接着利用PCA和LDA相结合得到最终的识别特征,最后采用欧式距离和最近邻分类器识别人脸。实验采用ORL标准人脸库验证了这种组合的有效性。  相似文献   

10.
光照变化会对人脸识别结果产生干扰,导致当前光照变化人脸识别结果不理想,为了降低光照变化对人脸识别结果的不利影响,以提高光照变化人脸识别效果,设计了基于Retinex算法的光照变化条件下人脸识别方法。采用激光传感器采集光照变化下的人脸图像,并对人脸进行格式转换,然后采用Retinex算法对转换后的人脸图像进行增强操作,消除光照变化对人脸图像干扰,改善人脸图像质量,最后采用模式识别技术设计人脸图像识别的分类器,并与其他人脸图像识别方法进行了对比测试。实验结果表明,本方法消除了不同光照变化的干扰,提高了人脸图像亮度、对比度和熵值,相对于对比方法,本方法的人脸识别精度更高,精度平均值达到了96%,而且加快了人脸识别速度,具有比较明显的优越性。  相似文献   

11.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

12.
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's.  相似文献   

13.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

14.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

15.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

16.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

17.
Waveguide multilayer optical card (WMOC) is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling & processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic (VB) language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor.  相似文献   

18.
It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output(MIMO) communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.  相似文献   

19.
The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well.  相似文献   

20.
An insert layer structure organic electroluminescent device(OLED) based on a new luminescent material (Zn(salen)) is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn(salen)/Liq/LiF/A1/CuPc/NPD/Zn(salen)/Liq/LiF/A1. Effective insert electrode layers comprising LiF(1nm)/Al(5 nm) are used as a single semitransparent mirror, and bilayer cathode LiF(1 nm)/A1(100 nm) is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect.  相似文献   

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