Enhancement of 3D Shape in 2D Natural Images using a Non-Photorealistic Shading Approach

This paper presents a non-photorealistic shading approach to enhance 3D shape appearance given in 2D natural images that do not have depth information. The approach is based on estimating and controlling normals on areas having relatively gentle shapes. Experimental results show effective and natural enhancement of 3D shapes, or improvement in 3D appearance.