Artistic relighting of paintings and drawings

We present a practical solution to the problem of subject relighting in paintings and drawings. Our interactive technique uses 3-D shading proxies and can be applied to objects with arbitrary geometries. Given a user-provided guess for the shading of an object in a painting/drawing and its corresponding target shading, we refine them using shading-color correlation and a multi-scale scheme. These refined shadings are then used to create a multi-channel shading-ratio image to perform relighting, while taking into account the colors used by the artists to convey shading information. We demonstrate the effectiveness of our solution on a variety of artistic styles, including paintings with strong brush strokes and unconventional shading encodings, drawings, and other types of artwork. Our method is the first to perform relighting of paintings and drawings and, in addition to relighting, can transfer smooth normal and depth maps from 3-D proxies to images.