CDIR: LoRA-Inspired Attention for Efficient Composite Degradation Image Restoration

Specialized image restoration methods have been extensively explored, each targeting a specific type of degradation. However, real-world images often suffer from composite degradations, prompting growing interest in unified restoration approaches. While recent unified models have shown promising results, many are hindered by high computational complexity, limiting their deployment in resource-constrained settings. Motivated by the parameter-efficient design of Low-Rank Adaptation (LoRA), we propose an efficient attention module specifically designed for composite degradation image restoration. The proposed method adopts a dual-branch architecture, where one branch processes features at full resolution, and the other operates with reduced spatial and channel dimensions to improve efficiency. To better adapt to diverse degradation patterns, the latter branch is further divided into two sub-branches, each incorporating dynamic operations guided by local and contextual priors. These context priors are iteratively updated within each module, drawing inspiration from feedback mechanisms in reinforcement learning, thereby enabling the model to effectively perceive and handle multiple degradation types within a unified structure. Additionally, we introduce a multi-scale feed-forward network to further enhance both performance and computational efficiency. Extensive experiments on two composite degradation benchmarks demonstrate that our proposed network, CDIR, achieves state-of-the-art performance with significantly reduced complexity and fast inference speed. In addition, CDIR shows strong adaptability to various task-specific image restoration scenarios, such as dehazing, desnowing, and deraining. It also performs robustly on domain-specific applications such as ultra-high-definition (UHD), remote sensing, and medical image restoration, highlighting its versatility and practical applicability.