Sparse Recovery via $\ell_1^2-η\ell_2^2$ Minimization
通过 ℓ₁²-ηℓ₂² 最小化的稀疏恢复
Lang Yu, Nan-jing Huang
AI总结 针对加权平方范数差惩罚 ℓ₁²-ηℓ₂² 最小化,建立了精确恢复的零空间性质条件和基于 RIP 的稳定恢复保证,并提出了基于 ADMM 的高效算法。
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加权平方范数差(WDSN)惩罚 ℓ₁²-ηℓ₂²(其中 0≤η≤1)因其在压缩感知和逆问题中强大的稀疏促进能力和良好的重构性能而备受关注。然而,WDSN 最小化的精确恢复保证和受限等距性质(RIP)分析尚未建立。本文填补了这一空白。首先,我们基于零空间性质(NSP)建立了精确恢复 k-稀疏信号的充分条件。然后,在 δ_{2k}-RIP 条件下,我们推导了 k-稀疏信号和一般信号的稳定恢复保证,并刻画了重构误差的上界。此外,我们提出了一种基于 WDSN 的正则化模型,以统一处理无噪声和有噪声观测。为了设计高效算法,我们推导了 WDSN 泛函近端算子的显式公式。基于该近端求解器,我们在交替方向乘子法(ADMM)框架内开发了一种合适的变量分裂方案,并在温和条件下建立了其全局收敛性。最后,数值实验表明,所提方法在无噪声和有噪声稀疏恢复任务中均优于迭代半变分方法。
The weighted difference of squared norms (WDSN) penalty $\ell_1^2-η\ell_2^2$ with $0\leq η\leq 1$ has attracted considerable attention due to its strong sparsity-promoting ability and favorable reconstruction performance in compressed sensing and inverse problems. However, exact recovery guarantees and restricted isometry property (RIP) analysis for WDSN minimization have not yet been established. In this paper, we address this gap. First, we establish sufficient conditions for the exact recovery of $k$-sparse signals based on the null space property (NSP). Then, under the $δ_{2k}$-RIP condition, we derive stable recovery guarantees for both $k$-sparse signals and general signals, and characterize upper bounds on the reconstruction error. Furthermore, we propose a WDSN-based regularized model to handle both noiseless and noisy observations in a unified framework. To design an efficient algorithm, we derive an explicit formula for the proximal operator of the WDSN functional. Based on this proximal solver, we develop a suitable variable-splitting scheme within the alternating direction method of multipliers (ADMM) and establish its global convergence under some mild conditions. Finally, numerical experiments show that the proposed method outperforms the iterative half variation method in both noiseless and noisy sparse recovery tasks.