3D or 3 Dimensional Display Technology

A 3D display is any display device capable of conveying a stereoscopic perception of 3-D depth to the viewer. The basic requirement is to present offset images that are displayed separately to the left and right eye. Both of these 2-D offset images are then combined in the brain to give the perception of 3-D depth. Although the term “3D” is ubiquitously used, it is important to note that the presentation of dual 2-D images is distinctly different from displaying an image in three full dimensions. The most notable difference is that the observer is lacking any freedom of head movement to increase information about the 3-dimensional objects being displayed. Holographic displays do not have this limitation, so the term “3D display” fits accurately for such technology.
Similar to how in sound reproduction it is not possible to recreate a full 3-dimensional sound field merely with two stereophonic speakers, it is likewise an overstatement of capability to refer to dual 2-D images as being “3D”. The accurate term “stereoscopic” is more cumbersome than the common misnomer “3D”, which has been entrenched after many decades of unquestioned misuse.
The optical principles of multiview auto-stereoscopy have been known for over 60 years. Practical displays with a high resolution have recently become available commercially.
Types of 3D Displays:
Stereoscopic: Based on the principles of stereopsis, described by Sir Charles Wheatstone in the 1830s, stereoscopic technology provides a different image to the viewer’s left and right eyes. Examples of this technology include anaglyph images and polarized glasses. Stereoscopic technologies generally involve special spectacles.
Autostereoscopic: Autostereoscopic display technologies use optical components in the display, rather than worn by the user, to enable each eye to see a different image. The optics split the images directionally into the viewer’s eyes, so the display viewing geometry requires limited head positions that will achieve the stereoscopic effect. Automultiscopic displays provide multiple views of the same scene, rather than just two. Each view is visible from a different range of positions in front of the display. This allows the viewer to move left-right in front of the display and see the correct view from any position. Example technologies include parallax barriers and specular holography.
Computer-generated holography: Research into holographic displays has produced devices which are able to create a light field identical to that which would emanate from the original scene, with both horizontal and vertical parallax across a large range of viewing angles. The effect is similar to looking through a window at the scene being reproduced; this may make CGH the most convincing of the 3D display technologies, but as yet the large amounts of calculation required to generate a detailed hologram largely prevent its application outside of the laboratory.
Volumetric displays: Volumetric displays use some physical mechanism to display points of light within a volume. Such displays use voxels instead of pixels. Volumetric displays include multiplanar displays, which have multiple display planes stacked up, and rotating panel displays, where a rotating panel sweeps out a volume.
Other technologies have been developed to project light dots in the air above a device. An infrared laser is focused on the destination in space, generating a small bubble of plasma which emits visible light.
Each of these display technologies can be seen to have limitations, whether the location of the viewer, cumbersome or unsightly equipment or great cost. The acquisition of artifact-free 3D images remains difficult. There are currently no guidelines or standards for multi-camera parameters, placement, and post- production processing, as there are for conventional 2D television.