  Recovering textures under shadows has remained a challenging problem due to
the difficulty of inferring shadow-free scenes from shadow images. In this
paper, we propose the use of diffusion models as they offer a promising
approach to gradually refine the details of shadow regions during the diffusion
process. Our method improves this process by conditioning on a learned latent
feature space that inherits the characteristics of shadow-free images, thus
avoiding the limitation of conventional methods that condition on degraded
images only. Additionally, we propose to alleviate potential local optima
during training by fusing noise features with the diffusion network. We
demonstrate the effectiveness of our approach which outperforms the previous
best method by 13% in terms of RMSE on the AISTD dataset. Further, we explore
instance-level shadow removal, where our model outperforms the previous best
method by 82% in terms of RMSE on the DESOBA dataset.
