论文标题
图像恢复:分段平滑功能的结构性低级矩阵框架
Image Restoration: Structured Low Rank Matrix Framework for Piecewise Smooth Functions and Beyond
论文作者
论文摘要
最近,将信号/图像映射到低级Hankel/Toeplitz矩阵中,由于其能够减轻连续域中的真实支持与离散网格之间的基本不匹配的能力,因此已成为传统稀疏正则化的新兴替代方法。在本文中,我们引入了一种新型的结构性低级矩阵框架,以恢复分段平滑功能。受到使用总体变化的启发,我们得出的是,高阶导数的傅立叶样品满足了歼灭关系,从而导致低级多倍Hankel矩阵。我们进一步观察到,低级Hankel矩阵的SVD对应于一个紧密的小波框架系统,该系统可以用稀疏的系数表示图像。基于此观察,我们还提出了基于小波框架分析方法的连续域正则化模型,以进行分段平滑图像恢复。最后,将图像恢复任务的数值结果作为概念验证研究提出,以证明所提出的方法可以与几种流行的离散正则化方法和结构化低级矩阵方法进行比较。
Recently, mapping a signal/image into a low rank Hankel/Toeplitz matrix has become an emerging alternative to the traditional sparse regularization, due to its ability to alleviate the basis mismatch between the true support in the continuous domain and the discrete grid. In this paper, we introduce a novel structured low rank matrix framework to restore piecewise smooth functions. Inspired by the total generalized variation to use sparse higher order derivatives, we derive that the Fourier samples of higher order derivatives satisfy an annihilation relation, resulting in a low rank multi-fold Hankel matrix. We further observe that the SVD of a low rank Hankel matrix corresponds to a tight wavelet frame system which can represent the image with sparse coefficients. Based on this observation, we also propose a wavelet frame analysis approach based continuous domain regularization model for the piecewise smooth image restoration. Finally, numerical results on image restoration tasks are presented as a proof-of-concept study to demonstrate that the proposed approach is compared favorably against several popular discrete regularization approaches and structured low rank matrix approaches.