共查询到17条相似文献,搜索用时 218 毫秒
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针对分块压缩感知算法在平滑块效应时损失了大量的细节纹理信息,从而影响图像的重构效果问题,提出了一种基于块稀疏信号的压缩感知重构算法。该算法先采用块稀疏度估计对信号的稀疏性做初步估计,通过对块稀疏度进行估算初始化阶段长,运用块矩阵与残差信号最匹配原则来选取支撑块,再运用自适应迭代计算实现对块稀疏信号的重构,较好地解决了浪费存储资源和计算量大的问题。实验结果表明,相比常用压缩感知方法,所提算法能明显减少运算时间,且能有效提高图像重构效果。 相似文献
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1-Bit压缩感知(CS)是压缩感知理论的一个重要分支。该领域中二进制迭代硬阈值(BIHT)算法重构精度高且一致性好,是一种有效的重构算法。该文针对BIHT算法重构过程需要信号稀疏度为先验信息的问题,提出一种稀疏度自适应二进制迭代硬阈值算法,简称为SABIHT算法。该算法修正了BIHT算法,首先通过自适应过程自动调节硬阈值参数,然后利用测试条件估计信号的稀疏度,最终实现不需要确切信号稀疏度的1-Bit压缩感知盲重构。理论分析和仿真结果表明,该算法较好地实现了未知信号稀疏度的精确重建,并且与BIHT算法相比重构精度及算法复杂度均相当。 相似文献
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压缩感知(compressed sensing, CS)稀疏信号重构本质上是在稀疏约束条件下求解欠定方程组。针对压缩感知匹配追踪(compressed sampling matching pursuit, CoSaMP)算法直接从代理信号中选取非零元素个数两倍作为支撑集,但是不存在迭代量化标准,本文提出了分步压缩感知匹配追踪(stepwise compressed sampling matching pursuit, SWCoSaMP)算法。该算法从块矩阵的逆矩阵定义出发,采用迭代算法得到稀疏信号的支撑集,推出每次迭代支撑集所对应重构误差的L-2范数闭合表达式,从而重构稀疏信号。实验结果表明和原来CoSaMP算法相比,对于非零元素幅度服从均匀分布和高斯分布的稀疏信号,新算法具有更好的重构效果。 相似文献
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观测值受脉冲噪声干扰情况下,传统的压缩感知算法基本失效,基于洛伦兹范数的硬阈值迭代(LIHT)算法是有效途径,但是硬阈值迭代过程会误判信号支撑集,随着脉冲数目增加,算法性能明显下降。针对这一问题,提出了一种基于洛伦兹范数的软阈值迭代(LIST)压缩感知重构算法。利用洛伦兹范数有效约束脉冲噪声,引入信号稀疏度度量函数,采用梯度下降法降低重构信号的稀疏度,实现软阈值迭代,并通过拟牛顿法求解该模型,加快算法收敛,运算量与其他算法是同一数量级,数值仿真表明,重构信噪比优于LIHT算法。 相似文献
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Compressed sensing, a new area of signal processing rising in recent years, seeks to minimize the number of samples that is necessary to be taken from a signal for precise reconstruction. The precondition of compressed sensing theory is the sparsity of signals. In this paper, two methods to estimate the sparsity level of the signal are formulated. And then an approach to estimate the sparsity level directly from the noisy signal is presented. Moreover, a scheme based on distributed compressed sensing for speech signal denoising is described in this work which exploits multiple measurements of the noisy speech signal to construct the block-sparse data and then reconstruct the original speech signal using block-sparse model-based Compressive Sampling Matching Pursuit (CoSaMP) algorithm. Several simulation results demonstrate the accuracy of the estimated sparsity level and that this denoising system for noisy speech signals can achieve favorable performance especially when speech signals suffer severe noise. 相似文献
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压缩感知理论突破了信号带宽对奈奎斯特采样定理的限制,并且实现了在数据采样的同时进行压缩。目前压缩感知系统通常利用图像在某个变换域具有稀疏性的先验知识,从少量观测值中重构原始图像。本文利用图像像素的邻域结构信息及图像子块的相似性,将图像的非局部相似性作为先验知识运用到压缩感知图像重构中。结合图像的非局部相似性及其在变换域的稀疏性先验知识,提出了基于非局部相似性和交替迭代优化算法的图像压缩感知重构算法,该算法利用迭代阈值法和非局部全变差来交替迭代求解变换域的稀疏性优化问题和非局部相似性的优化问题。实验结果表明,本文算法可以有效提高图像重构的视觉效果和峰值信噪比。 相似文献
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Compressed sensing gains great attention in the field of signal reconstruction. In order to deal with some practical cases in which the sparsity levels are unknown, this paper proposes an energy-based adaptive matching pursuit (EAMP) algorithm for binary sparse signal reconstruction in the compressed sensing framework. The EAMP algorithm inherits the feature of the sparsity adaptive matching pursuit algorithm, which increases the estimated sparsity level when the energy of the observation residue increases. Meanwhile, the proposed algorithm introduces the measurement vector into the signal reconstruction process. It uses two kinds of step sizes to increase the estimated sparsity level when the energy of the estimated candidate signal is less than half of that of the measurement vector. The experimental results indicate that the proposed EAMP algorithm provides better reconstruction performance than other greedy algorithms. 相似文献
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The data of wireless sensor network has strong joint sparse characteristics,by utilizing compressed sensing theory,compressed data by joint encoding,and then reconstructed the data by joint decoding,the sensed data can be gathered with low computational cost.A synchronous subspace pursuit algorithm based on joint sparse model and com-pressed sensing theory was proposed.By utilizing the sparsity of the sensed data,it selected the correct joint subspace and reconstruct the original signal group accurately with fewer observations in a backtracking iterative manner.Com-pared with SCoSaMP algorithm and SP algorithm,the proposed algorithm presents better data reconstruction perform-ance under the conditions of different sparsity and sampling rate. 相似文献
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压缩感知理论是近年来提出的一种新兴的基于信号稀疏性的采样理论。正交匹配追踪算法是其中一种典型的重构方法,文中针对语音信号重构中存在的不足,采用正交匹配追踪算法对语音信号进行信号重构,相比于传统的压缩感知的重构算法更加地适用于对含噪语音、重构语音质量会更高,去噪效果也会更明显。为语音信号CS性能的基础性的研究提供了参考。 相似文献