MambaLLIE: Implicit Retinex-Aware Low Light Enhancement with Global-then-Local State Space
Jiangwei Weng, Zhiqiang Yan, Ying Tai, Jianjun Qian, Jian Yang, Jun Li
TL;DR
MambaLLIE introduces a global-then-local state-space framework for low-light image enhancement that combines a Local-Enhanced State Space Module with an implicit Retinex-aware Selective Kernel. By integrating LayerNorm, augmented illumination priors, and a Retinex-guided feature selection mechanism, the method models global long-range dependencies while preserving local detail. Across five benchmark datasets and real-world tests, it consistently outperforms CNN/Transformer-based methods and prior Retinex approaches, with substantial PSNR gains and improved perceptual quality. The approach advances LLIE by unifying state-space modeling with Retinex priors, offering robust enhancement in challenging lighting and preserving color fidelity, with potential extensions to video and other low-level vision tasks.
Abstract
Recent advances in low light image enhancement have been dominated by Retinex-based learning framework, leveraging convolutional neural networks (CNNs) and Transformers. However, the vanilla Retinex theory primarily addresses global illumination degradation and neglects local issues such as noise and blur in dark conditions. Moreover, CNNs and Transformers struggle to capture global degradation due to their limited receptive fields. While state space models (SSMs) have shown promise in the long-sequence modeling, they face challenges in combining local invariants and global context in visual data. In this paper, we introduce MambaLLIE, an implicit Retinex-aware low light enhancer featuring a global-then-local state space design. We first propose a Local-Enhanced State Space Module (LESSM) that incorporates an augmented local bias within a 2D selective scan mechanism, enhancing the original SSMs by preserving local 2D dependency. Additionally, an Implicit Retinex-aware Selective Kernel module (IRSK) dynamically selects features using spatially-varying operations, adapting to varying inputs through an adaptive kernel selection process. Our Global-then-Local State Space Block (GLSSB) integrates LESSM and IRSK with LayerNorm as its core. This design enables MambaLLIE to achieve comprehensive global long-range modeling and flexible local feature aggregation. Extensive experiments demonstrate that MambaLLIE significantly outperforms state-of-the-art CNN and Transformer-based methods. Project Page: https://mamballie.github.io/anon/
