Depth-Aware Shadow Removal

Abstract

Shadow removal from a single image is an ill-posed problem because shadow generation is affected by the complex interactions of geometry, albedo, and illumination. Most recent deep learning-based methods try to directly estimate the mapping between the non-shadow and shadow image pairs to predict the shadow-free image. However, they are not very effective for shadow images with complex shadows or messy backgrounds. In this paper, we propose a novel end-to-end depth-aware shadow removal method without using depth images, which estimates depth information from RGB images and leverages the depth feature as guidance to enhance shadow removal and refinement. The proposed framework consists of three components, including depth prediction, shadow removal, and boundary refinement. First, the depth prediction module is used to predict the corresponding depth map of the input shadow image. Then, we propose a new generative adversarial network (GAN) method integrated with depth information to remove shadows in the RGB image. Finally, we propose an effective boundary refinement framework to alleviate the artifact around boundaries after shadow removal by depth cues. We conduct experiments on several public datasets and real-world shadow images. The experimental results demonstrate the efficiency of the proposed method and superior performance against state-of-the-art methods.