They say albedo map, but they seem to mean diffuse map? They also seem to be using 'reflectivity' in the physics sense, instead of the cg sense we usually mean. They say 'a measure of the reflectance', when I think they're trying to say 'a measure of the diffusely reflected light' aka, diffuse map.
Cool technique, but they're essentially generating a heightmap, no? Wouldn't normal map data still provide a more accurate version of the surface?