3D television


3D television is television that conveys depth perception to the viewer by employing techniques such as stereoscopic display, multi-view display, or any other form of 3D display. Most modern 3D television sets use an active shutter 3D system or a polarized 3D system, and some are autostereoscopic without the need of glasses., most 3D TV sets and services are no longer available from manufacturers.

History

The stereoscope was first invented by Sir Charles Wheatstone in 1838. It showed that when two pictures are viewed stereoscopically, they are combined by the brain to produce 3D depth perception. The stereoscope was improved by Louis Jules Duboscq, and a famous picture of Queen Victoria was displayed at The Great Exhibition in 1851. In 1855 the Kinematoscope was invented. In the late 1890s, the British film pioneer William Friese-Greene filed a patent for a 3D movie process. On 10 June 1915, former Edison Studios chief director Edwin S. Porter and William E. Waddell presented tests in red-green anaglyph to an audience at the Astor Theater in New York City and in 1922 the first public 3D movie The Power of Love was displayed.
Stereoscopic 3D television was demonstrated for the first time on 10 August 1928, by John Logie Baird in his company's premises at 133 Long Acre, London. Baird pioneered a variety of 3D television systems using electro-mechanical and cathode-ray tube techniques. The first 3D TV was produced in 1935, and stereoscopic 3D still cameras for personal use had already become fairly common by the Second World War. Many 3D movies were produced for theatrical release in the US during the 1950s just when television started to become popular. The first such movie was Bwana Devil from United Artists that could be seen all across the US in 1952. One year later, in 1953, came the 3D movie House of Wax which also featured stereophonic sound. Alfred Hitchcock produced his film Dial M for Murder in 3D, but for the purpose of maximizing profits the movie was released in 2D because not all cinemas were able to display 3D films. In 1946 the Soviet Union also developed 3D films, with Robinzon Kruzo being its first full-length 3D movie. People were excited to view the 3D movies, but were put off by their poor quality. Because of this, their popularity declined quickly. There was another attempt in the 1970s and 1980s to make 3D movies more mainstream with the releases of Friday the 13th Part III and Jaws 3-D.
Matsushita Electric developed a 3D television that employed an active shutter 3D system in the late 1970s. They unveiled the television in 1981, while at the same time adapting the technology for use with the first stereoscopic video game, Sega's arcade game SubRoc-3D. 3D film showings became more popular throughout the 2000s, culminating in the success of 3D presentations of Avatar in December 2009 and January 2010.
Though 3D movies were generally well received by the public, 3D television did not become popular until after the CES 2010 trade show, when major manufacturers began selling a full lineup of 3D televisions, following the success of Avatar. Shortly thereafter, consumer and professional 3D camcorders were released to the public by Sony and Panasonic. These used two lenses, one for each eye. Around the same time, the LG Optimus 3D, the Fujifilm FinePix Real 3D series, and the Nintendo 3DS were released. According to DisplaySearch, 3D television shipments totaled 41.45 million units in 2012, compared with 24.14 in 2011 and 2.26 in 2010. In late 2013, the number of 3D TV viewers started to decline, and by 2016, development of 3D TV was limited to a few premium models. Production of 3D TVs ended in 2016.

Technologies

There are several techniques to produce and display 3D moving pictures. The following are some of the technical details and methodologies employed in some of the more notable 3D movie systems that have been developed.
The future of 3D television is also emerging as time progresses. New technology like WindowWalls and Visible light communication are being implemented into 3D television as the demand for 3D TV increases. Scott Birnbaum, vice president of Samsung's LCD business, said that the demand for 3D TV would skyrocket in the next couple of years, fueled by televised sports. One might be able to obtain information directly onto their television due to new technologies like the Visible Light Communication that allows for this to happen because the LED lights transmit information by flickering at high frequencies.

Displaying technologies

The basic requirement is to display offset images that are filtered separately to the left and right eye. Two strategies have been used to accomplish this: have the viewer wear eyeglasses to filter the separately offset images to each eye, or have the light source split the images directionally into the viewer's eyes. Common 3D display technology for projecting stereoscopic image pairs to the viewer include:
In a CEATEC 2011 exhibition, Hitachi released glasses-free 3D projection systems that use a set of 24 projectors, lenses, and translucent half mirrors to superimpose 3D images with a horizontal viewing angle of 60 degrees and a vertical viewing angle of 30 degrees. Sony is also working on similar technologies.
Single-view displays project only one stereo pair at a time. Multi-view displays either use head tracking to change the view depending on the viewing angle, or simultaneous projection of multiple independent views of a scene for multiple viewers. Such multiple views can be created on the fly using the 2D-plus-depth format.
Various other display techniques have been described, such as holography, volumetric display, and the Pulfrich effect, which was used in Doctor Who Dimensions in Time, in 1993, by 3rd Rock From The Sun in 1997, and by the Discovery Channel's Shark Week in 2000.
3D glasses may reduce image brightness.

Producing technologies

Stereoscopy is the most widely accepted method for capturing and delivering 3D video. It involves capturing stereo pairs in a two-view setup, with cameras mounted side by side and separated by the same distance as is between a person's pupils. If we imagine projecting an object point in a scene along the line-of-sight for each eye, in turn; to a flat background screen, we may describe the location of this point mathematically using simple algebra. In rectangular coordinates with the screen lying in the Y–Z plane, with the Z axis upward and the Y axis to the right, with the viewer centered along the X axis; we find that the screen coordinates are simply the sum of two terms. One accounting for perspective and the other for binocular shift. Perspective modifies the Z and Y coordinates of the object point, by a factor of D/, while binocular shift contributes an additional term of s·x/, where D is the distance from the selected system origin to the viewer, s is the eye separation, and x is the true x coordinate of the object point. The binocular shift is positive for the left-eye-view and negative for the right-eye-view. For very distant object points, the eyes will be looking along essentially the same line of sight. For very near objects, the eyes may become excessively "cross-eyed". However, for scenes in the greater portion of the field of view, a realistic image is readily achieved by superposition of the left and right images provided the viewer is not too near the screen and the left and right images are correctly positioned on the screen. Digital technology has largely eliminated inaccurate superposition that was a common problem during the era of traditional stereoscopic films.
Multi-view capture uses arrays of many cameras to capture a 3D scene through multiple independent video streams. Plenoptic cameras, which capture the light field of a scene, can also be used to capture multiple views with a single main lens. Depending on the camera setup, the resulting views can either be displayed on multi-view displays, or passed along for further image processing.
After capture, stereo or multi-view image data can be processed to extract 2D plus depth information for each view, effectively creating a device-independent representation of the original 3D scene. These data can be used to aid inter-view image compression or to generate stereoscopic pairs for multiple different view angles and screen sizes.
2D plus depth processing can be used to recreate 3D scenes even from a single view and convert legacy film and video material to a 3D look, though a convincing effect is harder to achieve and the resulting image will likely look like a cardboard miniature.

3D production

of events such as live sports broadcasts in 3D differs from the methods used for 2D broadcasting. A high technical standard must be maintained because any mismatch in color, alignment, or focus between two cameras may destroy the 3D effect or produce discomfort in the viewer. Zoom lenses for each camera of a stereo pair must track over their full range of focal lengths.
Addition of graphical elements to a 3D picture must place the synthesized elements at a suitable depth within the frame, so that viewers can comfortably view the added elements as well as the main picture. This requires more powerful computers to calculate the correct appearance of the graphical elements. For example, the line of scrimmage that appears as a projected yellow line on the field during an American football broadcast requires about one thousand times more processing power to produce in 3D compared to a 2D image.
Since 3D images are effectively more immersive than 2D broadcasts, fewer fast cuts between camera angles are needed. 3D National Football League broadcasts cut between cameras about one-fifth as often as in 2D broadcasting. Rapid cuts between two different viewpoints can be uncomfortable for the viewer, so directors may lengthen the transition or provide images with intermediate depth between two extremes to "rest" the viewer's eyes. 3D images are most effective if the cameras are at a low angle of view, simulating presence of the viewer at the event; this can present problems with people or structures blocking the view of the event. While fewer camera locations are required, the overall number of cameras is similar to a 2D broadcast because each position needs two cameras. Other live sport events have additional factors that affect production; for example, an ice rink presents few cues for depth due to its uniform appearance.