RetinexDual: Retinex-based Dual Nature Approach for Generalized Ultra-High-Definition Image Restoration

TL;DR

RetinexDual introduces a dual-branch framework based on Retinex theory, combining spatial and frequency domain techniques to effectively restore ultra-high-definition images across multiple challenging tasks.

Contribution

It proposes a novel dual-network approach with specialized modules for reflectance correction and illumination adjustment, addressing limitations of traditional frequency or spatial methods.

Findings

Outperforms recent methods in deraining, deblurring, dehazing, and low-light enhancement.

Effective in reducing artifacts and restoring details in UHD images.

Ablation studies confirm the importance of each component.

Abstract

Advancements in image sensing have elevated the importance of Ultra-High-Definition Image Restoration (UHD IR). Traditional methods, such as extreme downsampling or transformation from the spatial to the frequency domain, encounter significant drawbacks: downsampling induces irreversible information loss in UHD images, while our frequency analysis reveals that pure frequency-domain approaches are ineffective for spatially confined image artifacts, primarily due to the loss of degradation locality. To overcome these limitations, we present RetinexDual, a novel Retinex theory-based framework designed for generalized UHD IR tasks. RetinexDual leverages two complementary sub-networks: the Scale-Attentive maMBA (SAMBA) and the Frequency Illumination Adaptor (FIA). SAMBA, responsible for correcting the reflectance component, utilizes a coarse-to-fine mechanism to overcome the causal modeling of mamba, which effectively reduces artifacts and restores intricate details. On the other hand, FIA ensures precise correction of color and illumination distortions by operating in the frequency domain and leveraging the global context provided by it. Evaluating RetinexDual on four UHD IR tasks, namely deraining, deblurring, dehazing, and Low-Light Image Enhancement (LLIE), shows that it outperforms recent methods qualitatively and quantitatively. Ablation studies demonstrate the importance of employing distinct designs for each branch in RetinexDual, as well as the effectiveness of its various components.