Stereoscopic Images and 3D Technology
Stereoscopic images are images that are produced through stereoscopy (.), a technique that captures visual information in three dimensions (3D) thus producing the illusion of depth.
The secret behind the technique is the presentations of a different image to each eye. Two different images are presented to the eye. But the eyes are “deceived “into perceiving the images as different aspects of the same image, thus producing the illusion of depth.
Stereoscopy has a long history
Stereoscopy works because of the innate properties of human vision. People have different capacities for perceiving depth. These are affected by binocular vision, spontaneous perception and binocular single vision. Al, three are required for a person to be able to view images in 3D. A person’s relative ability to view things this way is termed stereo acuity.
Stereoscopic filmmaking
In 1922 three great milestones were recorded in the journey of 3D technology
Stereoscopy is closely linked with the early film industry. The earliest attempts at stereoscopy started with the pioneering work of its inventor Sir Charles Wheatstone in 1840. Subsequent to this came the making of the first stereoscopic films using dual strip projection. This was done with anaglyph imaging which entailed the use of filters that produced an illusion of depth by the use of different filters, prominent among which was the red and cyan filters.
Stereoscopic images can be produced through several view patterns.
Side by side view entails the parallel view of two pictures placed side at close proximity to each other.
Stereographic cards and the stereoscope
This is a technique used in stereoscopic vision when the eyes are forced to cross over two images thus producing the optical illusion of a third image.
These were a series of pre-TV era viewing of objects using different types of viewers such as the View-Master and Stereo Realist viewers. They were used for viewing images through the view of cardboard folders with plastic lenses. With the advent of DVD and TV however, these techniques are largely of historical interest.
Head-mounted displays
Helmet-mounted displays fitted with two LCD displays. This was usable either the creation of virtual play or just for the viewing of stereo films.
3D Stereoscopic displays also involve the use of 3D glasses of various classes.
- LCD shutter glasses used Liquid Crystal Display based on the popular alternate frame sequencing.
- A circularly polarized glass filter involves the wearing of special lenses to produce 3D stereoscopic image views.
- Infitec glasses: Interference filter technology (Infitec) employs the technique of braking down the visible subsequence of light to a point that is not longer perceptible to the human eye, thus producing an illusion of depth.
- Complementary colour anaglyphs: employs the use of common multiple filters to produce a 3D image.
- Compensating diopter glasses tries to compensate for the wavelength difference between filters.
- "Red eye" shutterglasses is a red-filter that completely suppresses that green and blue component of the traditional RGB system. The result is very clear images due to the absence of a ghost image.
More recent applications
The face of stereoscopy has changed over the years however, at no time has there been such a change in the way stereoscopy operates as in the last few decades or so.
Initially, the application of 3D viewing remained exclusively for use in games and playstations. However, with the advent of graphic card accelerators and other devices, very large images can be internally transferred on the computer. This has caused a great increase in the application of stereoscopy to PCs.
Currently, the trend is towards stereoscopic viewing without the use of glasses. This phenomenon just being introduced in the latest 3D TVs. This brand new development is called autostereoscopy.
With the advent of stereoscopy, the future of stereoscopy is definitely set to change!