共查询到19条相似文献,搜索用时 359 毫秒
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为了解决信号压缩过程中旁瓣串扰问题并提高参数估计时频率的估计精度,在研究超分辨信号处理理论的基础上,从框架理论入手,提出了可改善系统性能的恒噪声灵敏度分解算法。首先在基于矩阵表示的超分辨信号处理模型的基础上,采用矩阵伪逆算子,进行基于信号压缩的微波成像处理,讨论了伪逆算子应用于信号分解过程中的噪声性能;然后针对伪逆算子导致系统噪声增益增加的问题,通过根据信号处理的噪声指标要求设定处理门限,实现对信号的超分辨处理。仿真实验结果表明,该方法可消除匹配滤波类算法不可避免的旁瓣串扰问题,并可在一定程度上改善系统分辨率性能。 相似文献
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该文推导了交替分离算法的Cramer-Rao界。交替分离算法的Cramer-Rao界涉及到矩阵的减逆,而矩阵减逆具有比通常Moore-Penrose广义逆更为宽松的定义条件,在理论上,一个确定矩阵有无数个减逆。为了建立分离算法的Cramer-Rao界,该文求出了一个确定矩阵的一个特定减逆矩阵。根据任一确定性定理,得到分离数据的密度分布函数,从而获得交替分离算法的Cramer-Rao界。交替分离算法的Cramer-Rao界将多信号对信号参数估计的影响能更直观反映出来。通过对交替分离算法的Cramer-Rao界的讨论,该文还给出了有关矩阵分离算子一些重要的性质。 相似文献
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从算子理论的角度阐明了一给定信号用框架的有发子许愿安任意精度逼近;提出了基于非正交函数系的图像自适应表示算法,该中有效地表示新信号的局部特征及能量分布,作者以Gaussian基函数为例对二维图象进行了实验。 相似文献
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针对面阵中的波达方向估计算法复杂度过大的问题,提出了一种改进的基于传播算子的二维面阵波达方向(Direction of Arrival,DOA)估计算法。该改进算法基于面阵平移不变性质,将原始子面阵在X和Y轴上分别平移得到两个子面阵,将两个子面阵相加得到虚拟子面阵,利用原始子阵和虚拟子面阵构造新的信号矢量,基于传播算子算法求出其特征值,特征值中的模值和相位值包含信源的二维角度信息,由此可求出自动配对的二维角度。与基于传播算子的二维DOA估计算法相比,该算法有效降低了运算复杂度,且保持性能相近。仿真实验验证了算法的有效性。 相似文献
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为了从含噪声的测量矢量中重构原始信号,研究了稀疏补分析模型下近似最优子空间追踪信号重构算法.针对直接采用稀疏综合模型下子空间追踪过程非最速梯度下降和信号重构概率不高的缺点,根据稀疏补分析模型下不同类型分析字典的结构特点来设计近似目标优化函数;改进了迭代追踪过程;优化了稀疏补取值方法;提出并实现了基于稀疏补分析模型的近似最优分析子空间追踪算法.仿真实验证明,当稀疏补运算符分别采用随机紧支框架和二维全变分矩阵时,算法的完全重构信号概率均明显高于ASP、AHTP、AIHT、AL1、GAP算法的完全重构信号概率;对于含高斯噪声的输入信号,算法的重构信号综合平均PSNR比相应的ASP、AHTP、AIHT算法分别提高了0.8dB、1.38dB、3.13 dB,但比GAP和AL1算法降低了0.32 dB和0.6dB.算法的完全重构概率与综合重构性能有了明显提高,收敛充分条件得到进一步简化. 相似文献
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Lixin Shen Manos Papadakis Ioannis A Kakadiaris Ioannis Konstantinidis Donald Kouri David Hoffman 《IEEE transactions on image processing》2006,15(5):1254-1263
We present a general mathematical theory for lifting frames that allows us to modify existing filters to construct new ones that form Parseval frames. We apply our theory to design nonseparable Parseval frames from separable (tensor) products of a piecewise linear spline tight frame. These new frame systems incorporate the weighted average operator, the Sobel operator, and the Laplacian operator in directions that are integer multiples of 45 degrees. A new image denoising algorithm is then proposed, tailored to the specific properties of these new frame filters. We demonstrate the performance of our algorithm on a diverse set of images with very encouraging results. 相似文献
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Estimation of image noise variance 总被引:4,自引:0,他引:4
Rank K. Lendl M. Unbehauen R. 《Vision, Image and Signal Processing, IEE Proceedings -》1999,146(2):80-84
A novel algorithm for estimating the noise variance of an image is presented. The image is assumed to be corrupted by Gaussian distributed noise. The algorithm estimates the noise variance in three steps. At first the noisy image is filtered by a horizontal and a vertical difference operator to suppress the influence of the (unknown) original image. In a second step a histogram of local signal variances is computed. Finally a statistical evaluation of the histogram provides the desired estimation value. For a comparison with several previously published estimation methods an ensemble of 128 natural and artificial test images is used. It is shown that with the novel algorithm more accurate results can be achieved 相似文献
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利用独立分量分析(ICA)和离散小波变换(DWT),提出了一种新的视频数字水印算法。该算法将二值图像和灰度图像分别置乱后用ICA混叠得到两幅图像,选取其中一个用来做嵌入的水印,另一个作为密钥保留,以此来增加水印的安全性;用ICA将水印嵌入在原始视频的DWT低频子带系数中,实现了水印信号的盲检测,同时针对帧剪裁、帧丢失、帧平均和MPEG编码等具有良好的鲁棒性。 相似文献
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In order to improve the service quality of radio frequency identification (RFID) systems, multiple objectives should be comprehensively considered. An improved brain storm optimization algorithm GABSO, which incorporated adaptive learning operator and golden sine operator into the original brain storm optimization (BSO) algorithm, was proposed to solve the problem of RFID network planning (RNP). GABSO algorithm introduces learning operator and golden sine operator to achieve a balance between exploration and development. Based on GABSO algorithm, an optimization model is established to optimize the position of the reader. The GABSO algorithm was tested on the RFID model and dataset, and was compared with other methods. The GABSO algorithm's tag coverage was increased by 9.62% over the Cuckoo search (CS) algorithm, and 7.70% over BSO. The results show that the GABSO algorithm could be successfully applied to solve the problem of RNP. 相似文献