Single-Image Shadow Removal Using 3D Intensity Surface Modeling.

Shadow removal from a single image is a challenging problem, whose solution is proposed in this study using 3D intensity surface modeling. Due to the high-order textural content in the original images, a direct modeling of the intensity surface of shadow image is difficult. In this study, image decomposition technology is used as an edge-preserving filter to remove the textural detail while keeping the local-smoothness pattern of image intensity surface. Using 3D modeling, a proper intensity surface of illumination in shadow region can be obtained based on that corresponding to the same texture in the non-shadow one. Thus, the intensity surface of shadow region can be compensated with a respective shadow-removal. Experimental results demonstrate the effectiveness of the proposed approach in the aspect of single-image shadow removal. In contrast to the alternative methods, it is not limited by additional assumptions or conditions; moreover, it can deal with the non-uniform and curved surface shadows, and is applicable to the shadow regions consisting of different types of textures.