Interactive Removal of Shadows from a Single Image Using Hierarchical Graph Cut

Abstract

We propose a method for extracting a shadow matte from a single image. The removal of shadows from a single image is a difficult problem to solve unless additional information is available. We use user-supplied hints to solve the problem. The proposed method estimates a fractional shadow matte using a graph cut energy minimization approach. We present a new hierarchical graph cut algorithm that efficiently solves the multi-labeling problems, allowing our approach to run at interactive speeds. The effectiveness of the proposed shadow removal method is demonstrated using various natural images, including aerial photographs.