Relightable holograms

A method of producing a hologram comprising the steps of:

• obtaining a plurality of images encoding reflectance data sets of one corresponding area of a plurality of areas on an object surface illuminated under different lighting conditions that are provided by a visible light source located at different positions relative to the object surface, the visible light source illuminating the one area at an angle differing from at least one other visible light source by:
• illuminating the object surface from a direction with the visible light source located at a particular position relative to the object surface;
• recording a reflectance data set for the corresponding one area of the illuminated object surface, the recorded reflectance data being different from that of other areas on the object surface;
• moving the visible light source to a new position relative to the particular position to illuminate the object surface from a different direction;
• repeating the illuminating, the recording and the moving steps a predetermined number of times for each of the different positions of the visible light source relative to the object surface;
• generating aggregated reflectance data for the corresponding one area on the object surface by overlaying reflectance data sets recorded under different lighting conditions;
• illuminating a light sensitive medium with the already recorded aggregated reflectance data for the corresponding one area on the object surface;
• and
• manufacturing a hologram for the corresponding one area from the illuminated light sensitive medium, the aggregated encoded reflectance data sets on the hologram for the corresponding one area being different from those of other areas of the plurality of areas on the object surface, the hologram having an aspect ratio equal to an aspect ratio of the corresponding one area such that the hologram can be adhered to a model of the object to occlude the corresponding one area on the model.