Integral imaging is an autostereoscopic and multiscopic three-dimensional imaging technique that captures and reproduces a light field by using a two-dimensional array of microlenses, sometimes called a fly's-eye lens, normally without the aid of a larger overall objective or viewing lens. In capture mode, each microlens allows an image of the subject as seen from the viewpoint of that lens's location to be acquired. In reproduction mode, each microlens allows each observing eye to see only the area of the associated micro-image containing the portion of the subject that would have been visible through that space from that eye's location. The optical geometry can perhaps be visualized more easily by substituting pinholes for the microlenses, as has actually been done for some demonstrations and special applications.
The result is a visual reproduction complete with all significant depth cues, including parallax in all directions, perspective that changes with the position and distance of the observer, and, if the lenses are small enough and the images of sufficient quality, the cue of accommodation — the adjustments of eye focus required to clearly see objects at different distances. Unlike the voxels in a true volumetric display, the image points perceived through the microlens array are virtual and have only a subjective location in space, allowing a scene of infinite depth to be displayed without resorting to an auxiliary large magnifying lens or mirror.
The concept was proposed and experimentally demonstrated in 1908 by Gabriel Lippmann. He called it, in French, "photographie intégrale", usually translated literally as "integral photography", which suggests the integration of a whole image from parts of many small ones. However, a more usual meaning of the French word "intégrale" is "complete" or "unabridged", so that "complete photography" is another valid translation of Lippmann's perhaps deliberately ambiguous name for it.
Experiments with integral video are now being worked on. Japan's NHK broadcasting company has shown off demos featuring a prototype display viewable from virtually any angle. Toshiba has also begun research into the technology.
- Integral History—Comprehensive history of integral imaging