Matrix Completion Via Reweighted Logarithmic Norm Minimization
Zhijie Wang, Liangtian He, Qinghua Zhang, Jifei Miao, Liang-Jian Deng, Jun Liu
TL;DR
This work tackles LRMC by introducing a reweighted matrix logarithmic norm (RMLN) as a nonconvex surrogate that more accurately approximates the rank than the nuclear norm. An ADMM-based solver accommodates any $0<p\le 1$, with a singular-value shrinkage step derived via a DC decomposition (Theorem 1) and reweighted proximal updates. Empirical results on image inpainting across Set12 and BSD68 demonstrate superior PSNR/SSIM to state-of-the-art LRMC methods, including under random and block masks, and show the reweighting strategy and $p$-parameter choice (notably $p=0.8$) yield robust performance. The proposed framework offers a more faithful rank surrogate with practical recovery benefits and potential extensions to noisy completion and robust PCA.
Abstract
Low-rank matrix completion (LRMC) has demonstrated remarkable success in a wide range of applications. To address the NP-hard nature of the rank minimization problem, the nuclear norm is commonly used as a convex and computationally tractable surrogate for the rank function. However, this approach often yields suboptimal solutions due to the excessive shrinkage of singular values. In this letter, we propose a novel reweighted logarithmic norm as a more effective nonconvex surrogate, which provides a closer approximation than many existing alternatives. We efficiently solve the resulting optimization problem by employing the alternating direction method of multipliers (ADMM). Experimental results on image inpainting demonstrate that the proposed method achieves superior performance compared to state-of-the-art LRMC approaches, both in terms of visual quality and quantitative metrics.
