We adopted an integral photography (IP) in this system because IP is indisputably the most ideal system among various 3D display systems developed to date. IP, which was invented by Lippmann in 1908 and has been improved continuously, has an advantage in that it provides both horizontal and vertical parallax without the need to wear stereo glasses.
Currently, popular autostereoscopic systems such as the lenticular system and parallax barrier system provide a parallax only in the horizontal direction. Therefore, viewers can see 3D objects from any position only within a certain field of view. In this respect, IP is a technology that has nearly the same advantages as holography. Moreover, IP is considerably more feasible than holography because silver halide photography and laser technology are not required. Composed of a normal flat panel display (FPD), such as a liquid crystal display or an organic light-emitting diode, as well as a fly’s eye lens, as illustrated in Fig. 2, IP is also electronically rewritable. Although color reproducibility depends on the FPD, the reproducibility is still generally excellent.
Nevertheless, IP has not been widely used until now. One possible reason is that the extremely high initial cost of fly’s eye lens production when produced using a metal mold. Conventionally, because the lens pitch of the fly’s eye lens is considered an integral multiple of the pixel pitch of FPD, the lens should be custom-made according to the pixel pitch of FPD. However, this step can be very costly.
The invention of the extended fractional view (EFV) method [3−5], which is a new method of synthesizing an IP image, drastically changed this situation. In the EFV method, both an integer and an arbitrary real number are allowed as ratio between the lens and pixel pitches. The physical difference between the pitches is processed by software. Therefore, the initial high cost of customizing a fly’s eye lens is reduced because a comparatively inexpensive ready-made fly’s eye lens can be used in combination with various FPDs.
IP is also effective in expressing the glittering effect of a material, such as gems, because the light emitted from each convex lens of a fly’s eye lens depends on its direction [6−8].