共查询到20条相似文献,搜索用时 93 毫秒
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为了准确快速地进行运动人体的步态识别,提出了一种基于主分量分析(PCA)和统一Hu矩融合的步态识别算法。将人体髋关节以下作为感兴趣区域,对图像序列中运动人体的感兴趣区域进行了分割,并提取主分量外形特征,同时计算感兴趣区域的统一Hu不变矩特征,将二者结合,构成步态序列的特征空间,采用支持向量机(SVM)分类器进行分类识别,通过MATLAB仿真实验验证了算法的有效性。实验结果表明,该算法识别速度快,具有较高的识别率。 相似文献
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为了实现液晶屏字符高效、精准的自动化检测,针对液晶屏字符显示的断线、亮度缺陷,提出一种基于多特征矩融合的液晶屏字符缺陷检测算法。首先提取原始液晶屏图像中ROI区域,使用Hu不变矩来描述字符的结构特征,采用Zernike矩来弥补Hu矩所不能描述的高阶矩信息;然后使用颜色矩来描述字符的颜色特征,采用灰度矩弥补颜色矩所不能描述的灰度信息,并运用2DPCA技术融合上述矩阵,通过欧氏距离来衡量标准图像融合特征矩阵与待检测图像融合特征矩阵之间的相似度,通过设定相似度阈值来达到缺陷检测的目的。实验的客观和主观评价结果表明:主观上,该算法具有一定的稳定性、实用性;客观上,该算法相比于同类算法具有较低的误判率1%、漏判率0%以及较高的效率0.6 s,基本满足实际检测需求。 相似文献
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提出了一种基于兴趣点的图像检索新方法ACSM(Annular Color and Shape Moment).利用兴趣点的位置信息,提取兴趣点周围局部区域的颜色矩特征和区域形状不变矩特征。ACSM算法不仅对平穆、旋转具有良好的鲁棒性,而且克服了传统颜色矩和形状不变矩没有位置信忠的缺陷。实验结果表明,由于将颜色和形状特征有机结合,ACSM算法有效提高了图像检索的准确性。 相似文献
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为了有效地对步态特征进行分类识别,提出了一种基于Radon变换和解析Fourier-Mellin变换的步态识别算法。该算法直接对在视频序列中检测到的灰度图像进行Radon变换,然后进一步对变换结果进行解析Fourier-Mellin变换,从而将原图像的旋转变化和尺度变化分别转化为相位变化和幅度变化,之后通过定义一族旋转与尺度不变函数提取目标图像的不变性特征进行分类识别。实验结果表明,与目前常用的基于Hu矩和Zernike矩的算法相比,由于不需要对目标图像二值化和归一化,从而可以保留图像的更多细节信息,避免了重采样与重量化误差,该算法应用于步态识别有更高的识别率,可以达到更好的识别效果。 相似文献
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针对微下击暴流、低空急流、顺逆风以及侧风低空风切变样本图像间的形状特性关系,主要研究了小波不变矩的特征提取技术在风切变识别中的应用.首先,采用基于三次B样条的小波不变矩提取风切变图像的形状特征.然后,将提取的特征通过Fisher线性判别分析(LDA)降低维数,实现风切变有效特征的提取.最后,采用三阶近邻分类器分类识别四种低空风切变.实验结果表明,该算法与应用Hu矩和Zernike矩特征进行分类识别相比,识别结果更加稳定,且平均识别率得到了较大提高,能够有效用于风切变图像的类型识别中. 相似文献
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三机时差频差联合定位精度分析 总被引:1,自引:1,他引:0
从时差频差联合定位方程组出发,基于牛顿迭代法求解定位结果,并从理论上分析定位误差,说明时差频差联合定位的特点。考虑到双机时差频差定位中固有的定位结果模糊和定位精度不高2个问题,提出三机联合定位,通过飞机的两两组合消除定位结果模糊,并通过数据融合提高定位精度。通过仿真验证三机定位相对于双机在解定位模糊和精度方面要优于双机定位。 相似文献
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针对多基测角交会、时差相差、时差频差定位系统复杂度高、同步要求高的问题,利用测距机(DME)系统测距模式中飞机与台站的通联关系,提出了一种对飞机无源定位的方法。已知地面DME台站位置和本机侦测点位置,通过对飞机地空测距询问信号、台站距离应答信号的到达时间、方位进行测量并进行解码分选,对解码分选结果进行关联聚类,再利用DME测距工作模式的随机询问特性进行询问-应答信号的时序匹配,最后根据配对信号的到达时间差、DME台站位置以及飞机方位对飞机进行计算定位。通过仿真分析证明了该方法的可行性,在固定DME台站位置已知的条件下该方法具有工程实践意义。 相似文献
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研究了基于测角的被动定位方法,分析了双站测角定位系统的测距精度,针对双站测角定位精度较低且在一些目标方位上出现的几何方位影响精度(Geometric Dilution of Precision,GDOP)问题,结合机载平台的结构特点,提出了一种适用于单架飞机的红外被动测角定位方法.该方法按照正交方式将四个测量站装载到机载平台上,构成两个正交的测角定位系统,通过恰当选取两个系统的定位信息,可有效克服GDOP问题.最后进行了仿真验证,结果表明该方法能够有效克服GDOP问题,提高定位精度. 相似文献
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Texture analysis was performed as part of an investigation of the information content of Landsat Thematic Mapper (TM) imagery. High-altitude aircraft scanner imagery from the Airborne Thematic Mapper (ATM) instrument was acquired over central California and used to simulate TM data. Edge density texture images were constructed by computation of proportions of edge pixels in a 31×31 moving window on a near-infrared ATM band. A training technique was employed to select computational parameters to maximize the difference between edge density measurements in urban and in rural areas. The results of classification of the texture images showed that urban and rural areas could be distinguished with texture alone, indicating that inclusion of texture in automated classification procedures could significantly improve their accuracy. 相似文献
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空管自动化系统雷达航迹与飞行计划自动相关浅析 总被引:1,自引:0,他引:1
空管自动化系统通过FDP(flight data processing飞行数据处理),收发AFTN电报,对飞行数据进行计算和推算,从而实现航空器的雷达航迹与飞行计划相关,为管制人员提供航空器的准确位置信息。文章主要介绍雷达航迹和飞行计划自动相关的基本原理,以此对大连空管自动化系统中自动相关的几种情况进行分析。 相似文献
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In this work we use real data provided by terminal pulse Doppler radar (WSR-88D) echoes to estimate the windshear hazards
disastrous for the aircraft takeoffs and landings. Briefly two different methods are used to estimate the received Doppler
moments. The second central moment which is the variance of the wind speed is called width or shear. A first method is in
the time domain and also called pulse-pair, while the second is in the frequency domain. The main aim of this study is a performances
comparison of results provided by the two mentioned methods and assumes that the power spectrums of the received signals are
approached with the Gaussian shape. 相似文献
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Mustafa Berkay Yilmaz Hakan Erdogan Mustafa Unel 《Signal Processing: Image Communication》2012,27(6):678-693
Facial features such as lip corners, eye corners and nose tip are critical points in a human face. Robust extraction of such facial feature locations is an important problem which is used in a wide range of applications. In this work, we propose a probabilistic framework and several methods which can extract critical points on a face using both location and texture information. The new framework enables one to learn the facial feature locations probabilistically from training data. The principle is to maximize the joint distribution of location and apperance/texture parameters. We first introduce an independence assumption which enables independent search for each feature. Then, we improve upon this model by assuming dependence of location parameters but independence of texture parameters. We model location parameters with a multi-variate Gaussian and the texture parameters are modeled with a Gaussian mixture model which are much richer as compared to the standard subspace models like principal component analysis. The location parameters are found by solving a maximum likelihood optimization problem. We show that the optimization problem can be solved using various search strategies. We introduce local gradient-based methods such as gradient ascent and Newton's method initialized from independent model locations both of which require certain non-trivial assumptions to work. We also propose a multi-candidate coordinate ascent search and a coarse-to-fine search strategy which both depend on efficiently searching among multiple candidate points. Our framework is compared in detail with the conventional statistical approaches of active shape and active appearance models. We perform extensive experiments to show that the new methods outperform the conventional approaches in facial feature extraction accuracy. 相似文献