SynthLight: Portrait Relighting with Diffusion Model by Learning to Re-render Synthetic Faces

Figure 1. SynthLight performs relighting on portraits using an environment map lighting. By learning to re-render synthetic human faces, our diffusion model produces realistic illumination effects on real portrait photographs, including distinct cast shadows on the neck and natural specular highlights on the skin. Despite being trained exclusively on synthetic headshot images for relighting, the model demonstrates remarkable generalization to diverse scenarios, successfully handling half-body portraits and even full-body figurines.