Surface normal estimation for use in rendering an image

Relightable free-viewpoint rendering allows a novel view of a scene to be rendered and relit based on multiple views of the scene from multiple camera viewpoints. Image values from the multiple camera viewpoints can be separated into diffuse image components and specular image components, such that an intrinsic color component of a relightable texture can be determined for a specular scene, by using the separated diffuse image components. Furthermore, surface normals of geometry in the scene can be refined by constructing a height map based on a conservative component of an initial surface normal field and then determining the refined surface normals based on the constructed height map.