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以巡线无人机巡航中识别高压输电线为背景,提出一种准确、实时的高压输电线检测与识别算法.首先,针对高压输电线成像是线状结构和低灰度值的特征而且其空间分布近似水平,提出一种基于方向约束的多尺度线状目标强化算法.此方法把近似水平方向的高压输电线目标强化出来的同时,能够很好地抑制竖直方向线状干扰物体和非线状背景及噪声.然后,对强化后的结果进行基于角度约束的Radon变换.由于高压输电线邻近区域的灰度分布近似,在Radon变换中引入用于识别高压输电线的识别因子,以获得高压输电线的识别结果,并抑制近似水平的干扰物体.实际的飞行试验结果表明,该算法对高压输电线识别具有很好的抗噪性、抗干扰性和实时性. 相似文献
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将contourlet变换和多级离散小波变换的 "多级" 概念引入到离散余弦变换中,并针对当前传统的离散余弦变换域水印算法不能有效旋转几何攻效抵抗击行进了特性的分析和改进.在此基础上提出了一种基于Radon变换和多级离散余弦变换的鲁棒性水印算法,该算法首先从多级离散余弦变换系数中选择适当的位置嵌入水印信息;同时在水印检测之前,利用Radon变换检测算法对待检测图像进行几何校正,然后提取水印信息.实验结果表明本文算法的鲁棒性优于常规基于离散余弦变换的数字水印算法,并且它的实时性不受多级变换的影响. 相似文献
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为满足无人机航拍对图像拼接实时性和鲁棒性的要求,提出一种基于改进ORB的无人机航拍图像拼接算法。首先,特征检测引入SURF算法中的海森检测算子,解决尺度不变性问题;其次,用ORB算法进行特征描述,使其具备旋转不变性;接着采用汉明距离进行准确高效的图像特征粗匹配;然后,用KNN算法去除误差较大的匹配,缩小搜索范围,用RANSAC算法再次提纯;最后,使用泊松融合进行图像无缝融合拼接。实验表明,改进ORB算法实时性好、鲁棒性强,处理速度是SURF算法的5倍,具有抗噪性、旋转不变性和尺度不变性。 相似文献
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针对传统的SIFT算法运行速度较慢、不适合处理实时性要求高的无人机遥感图像的缺点,提出了一种基于ORB特征的快速遥感图像拼接改进算法。首先通过ORB算法快速得到特征点和特征描述,采用K最近邻算法(KNN)进行粗匹配,然后采用随机抽样一致性算法(RANSAC)进行精匹配,最后使用改进的加权平均方法对图像进行融合拼接。实验结果表明,该算法在保证匹配精度的基础上,处理速度较经典的SIFT算法提高了41倍。在图像融合时,该算法能有效地消除拼接重影错位现象。 相似文献
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为了提高无人机航拍图像配准的实时性,通过分析无人机巡航高度相对稳定及图像缺乏高频的细节信息的特点,提出了一种改进SIFT特征点检测方法,显著提高了图像的配准速度,并构建了一个用于图像拼接的航空影像数据集进行实验验证.首先分析了SIFT(Scale Invariant Feature Transform)算法关于特征点尺度不变性的理论依据及实现方法,提出了消除冗余性能的策略;然后采用减少高斯金字塔阶数与层数以及选择在每阶的第三层图像开始检测极值点,以减小差分尺度空间规模的方法;最后在数据集上进行了与现有图像配准方法的对比实验.实验结果证明,所提方法能够获得匹配稳健、鲁棒性高的特征点,匹配耗时只有经典SIFT的1/10,该方法为无人机航拍图像快速拼接提供了技术支持. 相似文献
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适用于机场跑道识别的改进Hough变换 总被引:4,自引:0,他引:4
机场跑道的卫星图片经过处理后表现出来的骨架特征为边缘直线,在边缘图像中检测直线通常使用的方法是Hough变换(HT).由于(HT)是一种穷举式的搜索,在处理复杂图像时存在大量无效计算,实时性较差.针对机场跑道识别的实时性要求,提出一种改进的用于在二值图像中检测直线的快速Hough变换算法,此算法克服了标准Hough变换以图像边界点为扫描边界的缺点,并且能及时中断无谓的扫描,较好地解决了无效累积问题,实验证明,与标准Hough变换相比,它不仅具备Hough变换原有的高可靠性和抗干扰能力,而且具备Hough变换所不具备的高效性和低存储,克服了标准Hough变换的高计算代价和耗存储的缺点. 相似文献
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提出一种基于层叠分类器的快速相关跟踪算法。首先利用目标模板色彩分布信息对原始图像数据进行变换,锐化匹配相似度函数峰值,增强算法在复杂环境下的稳定性;然后提出了用平均灰度差和Harr型特征构造层叠分类器,分层刻画目标模板与搜索窗口在统计特征和局部特征上的相似性,并采用积分图快速计算特征,从而大幅度减少在非最优匹配点上的计算量,且特征计算与模板大小无关。大量实验结果表明,该算法大大降低了相关跟踪的时间复杂度,具有跟踪稳定、实时性强等特点。目前,以该算法为核心的实时目标跟踪系统对图像大小为320×240的视频序列内任意尺寸目标的平均处理速度达到20帧/s。 相似文献
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F. Deschenes D. Ziou Corresponding author M.-F. Auclair-Fortier 《International journal of remote sensing》2013,34(3):511-535
This paper describes an optimal line detector for the one-dimensional case which is derived from Canny's criteria, and an efficient approach for the detection of line junctions and line terminations. The line detector is extended to the two-dimensional case by operating separately in the x and y directions. An efficient implementation using an infinite impulse response (IIR) filter is provided. This implementation has the additional advantage that increasing the filter scale affects neither temporal nor spatial complexity. The detection algorithm for junctions and terminations is divided into two steps. First, given the lines extracted from the original image, a local measure of line curvature is estimated using the mean of the dot products of orientation vectors within a given neighbourhood. The second step involves the localization of junctions and terminations. Experimental results using several synthetic and real images demonstrate the validity of the two methods. 相似文献
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Hough transform modified by line connectivity and line thickness 总被引:8,自引:0,他引:8
Yang M.C.K. Jong-Sen Lee Cheng-Chang Lien Chung-Lin Huang 《IEEE transactions on pattern analysis and machine intelligence》1997,19(8):905-910
A modified Hough transform based on a likelihood principle of connectivity and thickness is proposed for line detection. It makes short as well as thick line segments easier to detect in a noisy image. Certain desirable properties of the new method are justified by theory and simulations 相似文献
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A fast two-dimensional line clipping algorithm via line encoding 总被引:9,自引:0,他引:9
Clipping of lines is an important operation in most graphics applications. Two main types of line clipping algorithms have been proposed, namely the encoding approach (with the Cohen-Sutherland algorithm as a representative) and the parametric approach (with the Liang-Barsky and the Cyrus-Beck algorithms as representatives.) The technique described in this paper is a new encoding approach. Unlike the Cohen-Sutherland algorithm, which encodes the end points of a line, the line is encoded. Based on the line code, appropriate clipping actions are performed. Experimental results demonstrate that the proposed algorithm outperforms the Cohen-Sutherland, the Liang-Barsky and the Cyrus-Beck algorithms. 相似文献
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For efficient firing in sloping grate bark furnaces, it is important to control the ash line position on the grate. The ash line is the border between burning fuel and fuel which is burned out (ash). Here, the problem of detecting the ash line with an image processing system is treated. The presentation of trend curves to the operator is of special interest. The process is slow and trend curves provide a memory that will assist the operator to improve the manual control of the process. In future development it may be possible to close the loop. An algorithm for detection of the ash line is presented. It is an optimization method where the position of the ash line is computed by maximizing a criterion. The criterion is tailored for the application and maximized by dynamic programming. The goal has been to obtain an algorithm suitable for implementation on a small personal computer. The algorithm has been tested on images taken from a videotape, showing the interior of an industrial bark furnace. Experimental results show that the algorithm can be used for the generation of trend curves. 相似文献
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目的 基于参考图像的线条画生成是非真实感绘制最为常见的应用之一。尽可能模拟艺术家的创作风格生成疏密得当、具有层次感的线条画是这类工作的主要目标和挑战。本文提出一个自适应线画图绘制算法。方法 首先,将场景图像分割成若干个区域,分别计算每个区域亮度的方差以及每个像素到边界的最小距离,将每个区域的方差和面积的比值作为该区域的复杂度。然后,计算能反映其显著视觉特征的边缘切向流场。最后,使用基于流的各向异性高斯差分滤波生成线条画。在构造边缘切向流时,每个位置的切向量由其邻域的切向量加权而得到。文中增加了一个新的系数项,对于邻域的任意一个位置,如果它和参考位置在区域分类中属同一个类别。则该位置的权值更大。基于流的高斯差分自适应滤波过程中,高斯差分滤波的尺度参数和复杂度以及到区域边界距离有关。细节越丰富,离边界越近,尺度参数取值越小,这样得到的边缘比较细,同时可以防止将相邻小细线条连接成粗线条。然后,将高斯差分滤波结果沿着流线方向进行高斯滤波,对于细节丰富的区域,边缘比较多,尺度参数取值比较小,所连接边缘比较短,可以减少错误边缘可能。结果 对生物、树林、建筑、山河等具有代表性的图像,采用本文算法进行自动实时进行线条绘制,实验结果表明,采用本文算法所生成的线条随着区域场景的复杂程度呈现不同粗细和浓淡的变化,具有一定的层次感。因而本文算法能生成视觉特征鲜明、风格化效果突出的线条画,且能处理各种复杂场景的图像。结论 本文自适应参数的线条画生成算法,其算法参数调节以及算法效果优于固定参数的算法,本文算法在处理日常生活中各类主题场景的图像时均能取得良好效果。 相似文献
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Tracking line segments 总被引:8,自引:0,他引:8
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E. V. Semeikina D. V. Yurin A. S. Krylov Kuo-Liang Chung Yong-Huai Huang 《Pattern Recognition and Image Analysis》2012,22(2):360-370
A scale-space algorithm for estimating the local curvature of lines (edges or isolines) is presented. Two variants of edge curvature estimation based on differential invariants are suggested and compared. The first variant uses the edge curvature formula derived in the paper and the second is based on image preprocessing, which allows one to use the isoline curvature formula for edge curvature estimation. An analysis of scale selection needed to reach a desired accuracy is presented. Also, noise influence analysis has been performed. The application of curvature estimation to detection of straight lines and circles is suggested and implemented. Curvature information usage in parametric curve detection speeds up search algorithms and makes the results more stable. 相似文献
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