arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1608.04517cs.CV
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核范数最小化方法的比较研究

A Comparative Study for the Nuclear Norms Minimization Methods

University of Electronic Science and Technology of China(电子科技大学);Nanyang Technological University(南洋理工大学);Nanjing Institute of Technology(南京工程学院);University of Macau(澳门大学)

Zhiyuan Zha, Bihan Wen, Jiachao Zhang, Jiantao Zhou, Ce Zhu

摘要:

核范数最小化(NNM)通常用于通过相等地收缩所有奇异值来近似矩阵秩。然而,在许多实际问题中,奇异值具有明确的物理意义,NNM可能无法忠实地近似矩阵的秩。为了缓解NNM的上述局限性,最近的研究表明,加权核范数最小化(WNNM)可以实现比NNM更好的秩估计,NNM将权重设置为奇异值的倒数。然而,它仍然缺乏一个严格的解释,为什么WNNM是更有效的比NMM在各种应用。在本文中,我们分析NNM和WNNM的角度来看,组稀疏表示(GSR)。具体地说,一个自适应字典学习方法的设计连接的秩最小化和GSR模型。基于该字典,我们证明了NNM和WNNM分别等价于GSR中的L1-范数极小化和加权L1-范数极小化。通过增强加权L1范数最小化的稀疏性,与稀疏表示中的L1范数最小化相比,我们解释了WNNM比NMM更有效。将图像的非局部自相似性(NSS)先验与WNNM模型相结合,应用于图像去噪。实验结果表明,WNNM比NNM更有效,并且在客观和感知质量方面优于几种最先进的方法。

英文摘要:

The nuclear norm minimization (NNM) is commonly used to approximate the matrix rank by shrinking all singular values equally. However, the singular values have clear physical meanings in many practical problems, and NNM may not be able to faithfully approximate the matrix rank. To alleviate the above-mentioned limitation of NNM, recent studies have suggested that the weighted nuclear norm minimization (WNNM) can achieve a better rank estimation than NNM, which heuristically set the weight being inverse to the singular values. However, it still lacks a rigorous explanation why WNNM is more effective than NMM in various applications. In this paper, we analyze NNM and WNNM from the perspective of group sparse representation (GSR). Concretely, an adaptive dictionary learning method is devised to connect the rank minimization and GSR models. Based on the proposed dictionary, we prove that NNM and WNNM are equivalent to L1-norm minimization and the weighted L1-norm minimization in GSR, respectively. Inspired by enhancing sparsity of the weighted L1-norm minimization in comparison with L1-norm minimization in sparse representation, we thus explain that WNNM is more effective than NMM. By integrating the image nonlocal self-similarity (NSS) prior with the WNNM model, we then apply it to solve the image denoising problem. Experimental results demonstrate that WNNM is more effective than NNM and outperforms several state-of-the-art methods in both objective and perceptual quality.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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