Image data of a scene is captured. Spectral profile information is obtained for the scene. A database of plural spectral profiles is accessed, each of which maps a material to a corresponding spectral profile reflected therefrom. The spectral profile information for the scene is matched against the database, and materials for objects in the scene are identified by using matches between the spectral profile information for the scene against the database. Metadata which identifies materials for objects in the scene is constructed, and the metadata is embedded with the image data for the scene.