共查询到20条相似文献,搜索用时 62 毫秒
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采用单光子雪崩二极管(SPAD)组成的接收阵列,可有效提升接收端的灵敏度,这对于远距离探测成像具有重要应用价值。因成像时间受限,SPAD阵列对于空中移动目标探测的成像结果存在分辨率低、特征信息少、背景干扰噪声多等问题。针对阵列弱成像条件下的目标快速识别问题,通过分析不同空中移动目标的结构运动与位移之间的角度变化特点,提出一种基于SPAD阵列探测的空中运动目标识别方法。该方法有效解决了跟踪探测实时性要求与目标识别准确性之间的矛盾,可以在没有先验信息的条件下完成跟踪和识别任务。为进一步说明基于光流特征的分析方法的优势,以旋翼型无人机、固定翼型无人机以及飞鸟等大小、形状类似的低空飞行目标为例,通过对不同的光流角度分布进行统计分析,在近似离散点的成像条件下实现了以上3类目标的有效识别分类。 相似文献
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基于序列图像的运动目标实时检测方法 总被引:19,自引:0,他引:19
运动目标检测是当前进行图像分析和理解以及在计算机视觉领域研究的热点,它被广泛地应用于靶场测量、目标监视、视频压缩、车辆跟踪和航空航天等领域。在参考大量文献资料的基础上,系统研究了近年来国内外已经比较成熟的一些算法,并把它们分成了7类。 相似文献
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为了准确、快速的在动态场景中对运动车辆进行检测,提出一种基于特征点光流聚类的车辆检测方法。该方法取Harris角点为特征量,通过对特征点做光流提取来剔除一些没有运动的干扰角点,然后再通过模糊U邻域(FUNN)聚类算法剔除噪音、孤立点和不感兴趣样本并实现前景和背景的分离,最后通过设定阈值判断前景目标是否是车辆。实验结果证明在复杂的动态场景中该算法具有更高的车辆识别率。 相似文献
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提出一种基于OpenCV图像库的运动目标处理算法仿真方法,介绍了OpenCV库的特点和VC6环境下的配置,通过调用库中的视频读写函数、图像特征计算和光流计算函数,得到运动目标的光流场,为运动目标状态分析和跟踪提供了基础,仅在图像库的基础上编写了少量代码就使算法得以实现,提高了编程效率。 相似文献
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提出了结合稀疏编码和空间约束的红外图像聚类分割新算法, 在稀疏编码的基础上融合聚类算法, 扩展了传统的基于K-means聚类的图像分割方法. 结合稀疏编码的聚类分割算法能有效融合图像的局部信息, 便于利用像素之间的内在相关性, 但是对于分割会出现过分割和像素难以归类的问题.为此, 在字典的学习过程中, 将原子的聚类算法引入其中, 有助于缩减字典中原子所属类别的数目, 防止出现过分割; 考虑到像素及其邻域像素具有类别属性一致性的特点, 引入了空间类别属性约束信息, 并给出了一种交替优化算法. 联合学习字典、稀疏系数、聚类中心和隶属度, 将稀疏编码系数同原子对聚类中心的隶属程度相结合, 构造像素归属度来判断像素所属的类别. 实验结果表明, 该方法能够有效提高红外图像重要区域的分割效果, 具有较好的鲁棒性.
关键词:
图像分割
稀疏编码
聚类
空间约束 相似文献
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针对摄像机与被检测目标同时运动时的目标检测问题,提出一种立体视觉与光流融合的运动目标检测算法。结合立体视觉技术设计了光流与自运动估计模型,运用车辆的运动信息和场景的深度信息估计因摄像机运动产生的自运动光流;采用多分辨率细化的Horn算法估计场景的混合光流;对混合光流和自运动光流进行差分运算,剔除背景中静态目标的运动干扰。经过一系列形态学滤波处理获得运动目标完整区域,依据光流的连通性对运动目标标号,并确定位置信息。以典型的交通场景为对象进行分析,实验结果表明该算法能有效地检测出动态背景下的运动目标。 相似文献
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基于光流分层方法的平面3D运动估测 总被引:1,自引:0,他引:1
无人机自主着舰末端视觉导引中舰机间相对位姿的估测,可以看作机载摄像机对甲板平面3D运动的估测。提出了一种光流分层方法:首先利用已知焦距的机载摄像机拍摄着舰靶标区域的图像序列,并采用Lucas方法计算相邻两帧图像的光流场;而后通过分层模型,将由光流场进行3D运动检测的非线性问题转化为了两个线性问题。该方法无需图像间的特征匹配,可线性解算出着舰靶标区域相对于无人机的三维运动参数,进而得到舰机间的相对位姿信息。计算机合成图和摄像机实拍图像的实验结果验证了该算法的正确性和有效性。 相似文献
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Fei Yu Mei Hui Wei Han Peng Wang Li-quan Dong Yue-jin Zhao 《Optics Communications》2010,283(23):4619-4625
Image block matching is one of the motion estimation methods for video inter-frame coding and digital image stabilization. The methods used for matching and searching will greatly affect the accuracy and speed of block matching. The block matching method based on the oblique vectors is suggested in this paper where matching parameters contain both horizontal and vertical vectors in the image blocks at the same time. Improved matching information can be obtained after making correlative calculations in the oblique direction. A novel search method of matching block based on the idea of simulated annealing is presented in this paper to improve the searching speed, accuracy and robustness in the fast operation of the block-matching motion estimation. The simulated annealing algorithm can easily escape from the trap of local minima effectively. With the two methods the block matching can be used for motion estimation at the real-time image processing system and high estimation accuracy can be achieved. An image stabilization system based on DSP (Digital Signal Processing) system is developed to verify this algorithm. Results show that both the matching accuracy and the search speed are improved with the methods presented. 相似文献
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利用直方图均衡化和灰度变换增强算法,不能有效增强红外图像目标。鉴于此,在研究红外图像特点的基础上,提出了一种自适应红外目标特征增强算法。该算法先对红外图像进行中值滤波,滤除掉图像中的随机噪声,然后利用直方图分割将红外图像分为目标和背景2部分,通过线性加权叠加抑制背景和增强目标。实验表明,该算法不仅能够根据红外图像中目标的灰度特性自适应地选取直方图分割阈值,而且在去除噪声和增加对比度的同时还抑制了背景,达到了预期的效果。该算法尤其适用于目标和背景像素比例相近时直方图具有局域双峰特征的红外图像中目标的增强。 相似文献
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一种新的目标运动分析方法 总被引:8,自引:0,他引:8
讨论一种新的目标运动分析方法,旨在解决远距离、低信噪比情况下的目标被动定位和参数估计问题。该方法原理简单,实现方便。通过计算机模拟验证了算法的性能,并在此基础上成功地处理了海上试验数据,获得了正确的目标轨迹。 相似文献
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Infrared small target detection plays an important role in applications including military reconnaissance, early warning and terminal guidance. In this paper, we present a fast method, called fast-saliency, with very low computational complexity, for real-time small target detection in single image frame under various complex backgrounds. Different from traditional algorithms, the proposed method is inspired by a recent research on visual saliency detection indicating that small salient signals could be well detected by a gradient enhancement operation combined with Gaussian smoothing, which is able to delineate regions of small targets in infrared images. Concisely, there are only four simple steps contained in fast-saliency. In order, they are gradient operation, square computation, Gaussian smoothing and automatic thresholding, representing the four procedures as highpass filtering, target enhancement, noise suppression and target segmentation, respectively. Especially, for the most crucial step, gradient operation, we innovatively propose a 5 × 5 facet kernel operator that holds the key for separating the small targets from backgrounds. To verify the effectiveness of our proposed method, a set of real infrared images covering typical backgrounds with sea, sky and ground clutters are tested in experiments. The results demonstrate that it outperforms the state-of-the-art methods not only in detection accuracy, but also in computation efficiency. 相似文献
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怎样提取混沌背景中信号的参数具有重要意义.在重构的相空间中,叠加有其他信号的混沌信号时间序列重构的点集会偏离混沌吸引子所在光滑流形,依据这一性质并综合利用混沌背景中信号本身的特性,提出一种参数估计的新方法:最小相对奇异值(MRSV)法.该方法先建立逆滤波器,由其输出重构相空间,然后改变其参数,使输出信号在嵌入空间中作局部奇异值分解的相对奇异值最小,来实现参数估计.AR模型参数和正弦信号频率估计的仿真结果验证了该方法的有效性.
关键词:
混沌
参数估计
最小相对奇异值(MRSV)
逆滤波器 相似文献
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Wei Liu Wenxiao Shi Yaowen Lv Jingtai Cao Yumei Yin Yuanhao Wu Jihong Wang Xuefen Chi 《Optik》2013,124(24):6840-6845
Camera pose estimation is a basic and crucial problem in computer vision, accordingly a novel method is proposed for pose estimation based on parabolic motion in our paper. Firstly, the intersection of lines which are the image plane projection of free-falling trajectories in different locations is computed. According to the properties of vanishing point, the intersection is defined as the vanishing point in gravity direction. Secondly, the image plane projected curve of parabolic trajectory is obtained by Sampson Approximation. Finally, the camera pose is estimated by employing the projective geometry properties of vanishing point and vanishing line implicated in the projected parabola, provided that the intrinsic parameters of camera are specified. The absolute Euclidean distance of translation is obtained innovatively with the known frame frequency. Numerical simulation as well as practical experiment in this paper demonstrates the correctness and feasibility of our method, with the known frame frequency, as the experiment show that compared with the traditional checkerboard method the mean errors of rotation axis, rotation angle and translation are respectively 0.017 rad, 0.007 rad and 11.650 mm by our method. It can generally satisfy the accuracy requirements of camera. 相似文献