Integral imaging, also called integral photography, offers a true 3D image. The features of such a true 3D perception are:
a. binocular disparity as treated in Section 1.1;
b. the focusing point (accommodation) matching the convergence as described in Section 1.2; and
c. motion parallax.
The first two requirements are known from stereopsis as treated in Chapter 1, where it was mentioned that a mismatch of accommodation and vergence can cause discomfort at viewing distances that are too short. Stereoscopic and autostereoscopic displays do not meet requirement (b) as the focusing point is always on the display screen, no matter if the left and right eye images convey a disparity on the retina pertaining to a different distance or depth. By motion parallax, the ability of the viewer to move around the displayed 3D image is described, while perceiving the object differently corresponding to the viewer's different locations and viewing angles. These different views are also encountered in autostereoscopic displays with lenticulars or barriers, as treated in Sections 3.1, 3.2, 3.3, 3.4. A special arrangement of pixels was needed for the different views presented in different viewing zones of the lenticular. Although the distance between the viewer and points on the screen increases as the viewer moves to the side, full motion parallax is not ensured as the picture is restricted to the plane of the screen and the viewer to the line along the viewing zone. ...