R ² SFD: Improving Single Image Reflection Removal using Semantic Feature Dictionary

Single image reflection removal is a severely ill-posed problem and it is very hard to separate the desirable transmission and undesirable reflection layers. Most of the existing single image reflection removal methods try to recover the transmission layer by exploiting cues that are extracted only from the given input image. However, there is abundant unutilized information in the form of millions of reflection free images available publicly. Even though this information is easily available, utilizing the same for effectively removing reflections is non-trivial. In this paper, we propose a novel method, termed R^2SFD, for improving single image reflection removal using a Semantic Feature Dictionary (SFD) constructed from a database of reflection-free images. The SFD is constructed using a novel Reflection Aware Feature Extractor (RAFENet) that extracts features invariant to the presence of reflections. The SFD and the input image are then passed to another novel network termed SFDNet. This network first extracts RAFENet features from the reflection-corrupted input image, searches for similar features in the SFD, and transfers the semantic content to generate the final output. To further improve reflection removal, we also introduce a Large Scale Reflection Removal (LSRR) dataset consisting of 2650 image pairs comprising of a variety of real world reflection scenarios. The proposed method achieves superior results both qualitatively and quantitatively compared to the state of the art single image reflection removal methods on real public datasets as well as our LSRR dataset. We will release the dataset at https://github.com/ee19d005/r2sfd.