Abstract: A hologram having a covert image is made by recording on the hologram an object beam that will reconstruct an unrecognizable, scrambled image. The scrambled image can be modified to form a recognizable image by passing the scrambled image through a plate overlying the hologram.

Abstract: Computer-processed or computer-generated objects can be used to build holograms whose images are close to or straddle the hologram surface. No preliminary or first hologram is required. The hologram is built up from a number of contiguous, small, elemental pieces. Unorthodox views from inside the object are required for the creation of these elements. One method of generating the views employs unique object manipulations. The computational transformations ensure that no singularities arise and that more-or-less conventional modeling and rendering routines can be used. With a second method, a multiplicity of conventional object views are collected. Then, all pixels in these conventional viewplanes are reassigned to new and different locations in the new viewplanes for the elemental views. These methods may be used to build rainbow holograms or full parallax holograms. When properly executed they are visually indistinguishable from other types.

Abstract: Computer-processed or computer-generated objects can be used to build holograms whose images are close to or straddle the hologram surface. No preliminary or first hologram is required. The hologram is built up from a number of contiguous, small, elemental pieces. Unorthodox views from inside the object are required for the creation of these elements. One method of generating the views employs unique object manipulations. The computational transformations ensure that no singularities arise and that more-or-less conventional modeling and rendering routines can be used. With a second method, a multiplicity of conventional object views are collected. Then, all pixels in these conventional viewplanes are reassigned to new and different locations in the new viewplanes for the elemental views. These methods may be used to build rainbow holograms or full parallax holograms. When properly executed they are visually indistinguishable from other types.

Abstract: Computer-processed or computer-generated objects can be used to build holograms whose images are close to or straddle the hologram surface. No preliminary or first hologram is required. The hologram is built up from a number of contiguous, small, elemental pieces. Unorthodox views from inside the object are required for the creation of these elements. One method of generating the views employs unique object manipulations. The computational transformations ensure that no singularities arise and that more-or-less conventional modeling and rendering routines can be used. With a second method, a multiplicity of conventional object views are collected. Then, all pixels in these conventional viewplanes are reassigned to new and different locations in the new viewplanes for the elemental views. These methods may be used to build rainbow holograms or full parallax holograms. When properly executed they are visually indistinguishable from other types.