DURRNET: Deep Unfolded Single Image Reflection Removal Network with Joint Prior

Single image reflection removal (SIRR) problem can be interpreted as a canonical blind source separation problem and is highly ill-posed. A parameter effective, fast learning and interpretable reflection removal algorithm is essential for many vision analysis applications. In this paper, we propose a novel model-inspired and learning-based SIRR method called Deep Unfolded Reflection Removal Network (DURRNet). It combines the merits of both model-based and learning-based paradigms, leading to a more interpretable and effective deep architecture. To achieve this, we first propose a model-based optimization approach and then obtain DURRNet by unfolding an iterative step into a Unfolded Separation Block (USB) based on proximal gradient descent. Key features of DURR-Net include the use of Invertible Neural Networks to impose the transform-based exclusion prior on the basis of natural image prior, as well as a coarse-to-fine architecture to fine-grain the reflection removal process. Extensive experiments on public datasets demonstrate that DURRNet achieves state-of-the-art results not only visually, quantitatively, but also effectively.