共查询到18条相似文献,搜索用时 140 毫秒
1.
2.
Radon变换被广泛用于合成孔径雷达SAR图像上舰船尾迹的检测.由于舰船尾迹在SAR图像上呈现线性特征,并对应于Radon变换域中亮或暗的峰值点,因此通过检测变换域中的峰值点可以确定舰船尾迹.提出了一种新的基于Radon变换的SAR图像舰船尾迹检测算法IADA(Improved Automatic Detection Algorithm).考虑到海杂波的影响,IADA算法主要利用局部自适应检测算法来搜索变换域峰值点;另外还采用方向梯度算法来搜寻被检测到尾迹的起点.在真实SAR图像上的检测结果证明了该算法的有效性和准确性. 相似文献
3.
介绍了海洋表面合成孔径雷达(SAR)图像的舰船尾迹检测算法.该算法首先对图像进行对数变换,将乘性噪声转化为加性噪声,然后对图像进行非亚采样contourlet变换,根据变换后的像素均值对变换系数进行调整,以便去除噪声和提取尾迹轮廓.接着对经非亚采样contoulet调整后的图像进行局部Radon变换,即在对像素积分过程中沿着线性特征被分割后的若干短线段进行积分,而非对整幅图像进行积分.最后通过采用形态学膨胀和腐蚀的方法将临近的分离短线段连接起来便于后续的处理.采用该算法对实际SAR图像进行舰船尾迹检测,结果表明:该算法在背景噪声很强时仍能检测出略微有弯曲的尾迹信号. 相似文献
4.
介绍了海洋表面合成孔径雷达(SAR)图像的舰船尾迹检测算法。该算法首先对图像进行对数变换,将乘性噪声转化为加性噪声,然后对图像进行非亚采样contourlet 变换,根据变换后的像素均值对变换系数进行调整,以便去除噪声和提取尾迹轮廓。接着对经非亚采样contoulet调整后的图像进行局部Radon变换,即在对像素积分过程中沿着线性特征被分割后的若干短线段进行积分,而非对整幅图像进行积分。最后通过采用形态学膨胀和腐蚀的方法将临近的分离短线段连接起来便于后续的处理。采用该算法对实际SAR图像进行舰船尾迹检测,结果表明:该算法在背景噪声很强时仍能检测出略微有弯曲的尾迹信号。 相似文献
5.
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
6.
复制粘贴(Copy-Move)是一种极为常见的图像篡改方式。为了快速有效地检测图像经过旋转、缩放等操作后的篡改图像,本文提出了一种基于Radon和解析Fourier-Mellin变换的篡改图像盲检测方法。文章首先对图像进行分块,之后将图像块进行Radon和解析Fourier-Mellin变换,并提取计算变换结果后的矩特征值,最后计算矩特征值的相关性。本文算法不需要对灰度图像进行二值化与归一化处理,而是直接从图形的Radon变换与Fourier-Mellin变换的结果中提取不变特征,理论分析与实验结果表明,本文提出算法的检测结果优于基于正交矩的检测方法,而且对均值为0的白噪声的鲁棒性显著高于基于正交矩的检测方法。 相似文献
7.
针对传统的Radon变换直线检测算法运行时间长、占用存储空间大的问题,提出了一种基于二分查找的Radon变换直线检测改进算法。在Radon变换直线检测算法的基础上,增加了对图像中待检测直线最小夹角的约束条件,使用区间划分结合二分查找的方法对Radon变换直线检测算法进行改进,并通过待检测直线在Radon空间中的位置参数确定出待检测直线在原始空间的直线方程。实验结果表明,相比于Radon变换直线检测算法,所提出的改进算法在保证抗噪声干扰能力不受影响的前提下,有效减少了高检测精度要求下图像直线检测算法的运行时间和占用的存储空间,提高了直线检测的实时性。 相似文献
8.
随着我国交通服务行业的发展,火车票票面信息的自动化识别已经成为提升铁路服务效率的重要手段,针对票面信息识别系统中获取火车票方向不一致的问题,本文提出了一种基于特征区域聚类下Radon变换的方向检测算法。首先,算法通过k均值聚类对火车票图像进行聚类分块,消除复杂背景的干扰,提取到火车票信息区域;然后,通过数字形态学闭运算结合图像块操作保留能够反映火车票位置信息的图像方向特征区域;最后,利用改进的Radon变换检测出火车票的倾斜角度。实验结果表明:该算法的矫正正确率为97.8%,矫正的时间为16.79s;该算法能够消除图像复杂背景、方向特征区域领域像素点对方向检测的干扰,能够对全角度任意方向的火车票图像进行方向检测,具有较高的实用价值。 相似文献
9.
10.
11.
Copeland A.C. Ravichandran G. Trivedi M.M. 《Geoscience and Remote Sensing, IEEE Transactions on》1995,33(1):35-45
Presents a Radon transform-based approach to the detection of ship wakes in synthetic aperture radar (SAR) images. The key element of this technique is a localization of the Radon transform, whereby the intensity integration is performed over short line segments rather than across the entire image. A linear feature detection algorithm, which utilizes this localized Radon transform, is then developed. In this algorithm, referred to as the feature space line detector algorithm, the transform space is subjected to processing which serves to isolate and locate the response of linear features and suppresses the response of false alarms. This algorithm is tested on both synthetic images corrupted by various levels of Weibull multiplicative noise and on actual SAR images of ship wakes. The results of this testing demonstrate the algorithm's robustness in the presence of noise, as well as its ability to detect and localize linear features that are significantly shorter than the image dimensions 相似文献
12.
We propose an on-board selection scheme for aerial and space images, based on linear feature detection in a feature hyperspace. The detection task is performed by means of the Radon transform (RT) and the wavelet transform; a fast algorithm for the RT computation is described, and counteractions against the discretization errors are proposed. A new, wavelet-based algorithm is introduced, which performs a fine analysis of the waveforms of the RT peaks, yielding a possibly error-free detection in images corrupted by a high level of noise. A technique, based on the feature hyperspace, is proposed, able to significantly exploit all the available pieces of information on these peaks. Results of the tests on synthetic and real images are reported, which show that this method achieves satisfactory results, making the detection task highly reliable in the presence of both noise and clutter. 相似文献
13.
14.
15.
16.
17.
基于Radon变换的多尺度虹膜特征提取算法 总被引:3,自引:0,他引:3
系统分析了基于虹膜特征的身份识别系统.针对典型预处理特点,设计了基于Radon变换的新特征提取算法.该算法在保持旋转、平移和尺度缩放不变性的同时,利用标准化方差加权的绝对距离,使识别准确度达到了93%.这种算法对于其它不规则图像的分析也具有启发意义. 相似文献
18.
A new algorithm for fast curve parameter estimation based on the generalized Radon transform is proposed. The algorithm works on binary images, obtained, e.g., by edge filtering or deconvolution. The fundamental idea of the suggested algorithm is the use of a precondition map to reduce the computational cost of the generalized Radon transform. The precondition map is composed of irregular regions in the parameter domain, which contain peaks that represent curves in the image. To generate the precondition map, a fast mapping procedure named image point mapping is developed. As the image point mapping scheme maps image points into the corresponding parameter values in the parameter domain, it is possible to improve computational efficiency by recognizing image points with value zero. Initially, the suggested algorithm estimates the precondition map and subsequently applies the generalized Radon transform within the regions specified by the precondition map. The required parameter domain sampling and the resulting blurring are also investigated. The suggested algorithm is successfully applied to the identification of hyperbolas in seismic images, and two numerical examples are given. 相似文献