CU-Mamba: Selective State Space Models with Channel Learning for Image Restoration
Rui Deng, Tianpei Gu
TL;DR
The paper addresses image restoration by overcoming CNN and Transformer limitations in modeling long-range dependencies and computational cost. It introduces CU-Mamba, a U-Net variant that embeds a Spatial SSM for global spatial context and a Channel SSM for channel mixing, both enabled by a selective gating mechanism that preserves linear complexity, yielding a total cost of $\\mathcal{O}(BE(L+C))$. Through extensive denoising and deblurring experiments, CU-Mamba demonstrates state-of-the-art performance with lower computational overhead compared to Transformer-based methods, supported by ablations that validate the complementary roles of Spatial and Channel SSM blocks. The work demonstrates that jointly modeling spatial and channel contexts in a dual-directional SSM framework provides a practical and effective route for high-quality image restoration at scale.
Abstract
Reconstructing degraded images is a critical task in image processing. Although CNN and Transformer-based models are prevalent in this field, they exhibit inherent limitations, such as inadequate long-range dependency modeling and high computational costs. To overcome these issues, we introduce the Channel-Aware U-Shaped Mamba (CU-Mamba) model, which incorporates a dual State Space Model (SSM) framework into the U-Net architecture. CU-Mamba employs a Spatial SSM module for global context encoding and a Channel SSM component to preserve channel correlation features, both in linear computational complexity relative to the feature map size. Extensive experimental results validate CU-Mamba's superiority over existing state-of-the-art methods, underscoring the importance of integrating both spatial and channel contexts in image restoration.
