3D Displays, Continued
DLP 3D Television
Texas Instruments licenses Digital Light Processing (DLP) technology to both Mitsubishi and Samsung, and both manufacturers offer 3D televisions and projectors based on rear-projection DLP technology. These TVs are designed to accept a 3D video signal where the picture for the left and right eyes is downsampled in a grid pattern known as “checkerboard.” This allows a 3D signal to be delivered to the TV in a standard (non-3D) video signal format through a standard HDMI 1.3 connection (though the real resolution of each video frame is half of the original signal resolution).
The DLP TV decodes the incoming checkerboard-encoded frames, separating the correct pixels for the left and right video frames, then upsampling each frame to the full TV resolution. As with other compressed 3D formats, half of the original picture resolution is lost in this process.
DLP 3D televisions use active shutter glasses to display 3D programs as 120 Hz sequential frames.
Note that while DLP televisions and projectors may be advertised as “3D-Ready,” until models are available that support a full–resolution, dual-stream 3D video signal through HDMI 1.4, consumers should check to see if their chosen set-top Blu-ray 3D player can support their DLP TV by outputting a checkboard video signal. If not, the consumer will need to purchase a 3D-to-checkboard adapter (Mitsubishi offers a 3DC-1000 adapter).
Autostereoscopic Displays
Autostereoscopic displays are capable of displaying a 3D image without the use of 3D glasses. These displays use lenses that are designed to assure that each eye sees the video signal meant for that eye. There are several manufacturers working to produce and market autostereoscopic displays. While autostereoscopic displays promise 3D video without the need for glasses, consumers should consider both the 2D and 3D video quality compared with other display solutions before selecting a display.
Head-Mounted Displays
A head-mounted display is like a pair of glasses containing small displays in place of the lenses. With a head mounted display, a separate display is used for each image.
Unfortunately, consumer-grade head mounted displays today are not capable of displaying a high-definition video signal.
Great article! Thanks! - Jon
core i5, gtx2 9800, nvidia 3d vision... am I good to go?
Anaglyphic 3d glasses FTW!
Also, you fail to mention that interlacing the image is highly impractical due to compression techniques.
You forgot the compatible Blu-ray player?
vesa connector for TVs
http://en.wikipedia.org/wiki/VESA_Stereo
Why do we still call them set-top boxes? I mean, its been years since a television has been deep enough or flat enough to sit the box on top of the set! At least, not without some form of super strong adhesive.
I've yet to enjoy a 3D film (and not just because Avatar was crap I might add). I think I may have issues with accomodation and blur disparity.
I was just looking as some samsung 3dtv's, they seem to have the ability to process 2d video such as standard non 3d tv transmissions into 3d video display.
How is that done without this info being in the video stream?
^ and is this also possible using nvidia graphics cards and shutter glasses?
This story is sponsored by Hollywood and all the film studios desperately trying to come up with something that will keep people going to the cinema. Notice how all films are 3D at the moment? Perhaps if they reduced the price of cinema admission and Bluray Discs, they would make enough money to stop feeding us this rubbish. Since most films will be viewed on standard TV sets, why would we want all that extra cash to be spent on 3D tech during the filming stage?
As an aside, did anyone see the film called Primer? Now THAT was a good film!
Indeed, lol, Primer was superb and was also funded on a shoestring!
A very well-written article, thanks! I would like to increase the scope of this paragraph, however:
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"Another important parameter is the angle of convergence. 3D camera lenses that are aligned in parallel will result in a picture where all objects appear to be in front of the TV screen (or display). Objects at an infinite distance will appear to be on the screen. To create a stronger 3D effect, camera lenses can be angled (converged) slightly inward. With this setup, objects at the distance where the optical axes of both lenses converge will later appear to be on the screen. Closer objects will appear in front of the screen, and farther objects will appear to be behind the screen."
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Converging the lenses causes keystone distortion that has to be corrected in post, if severe, and objects that reside far behind that point in the subject space where the lens axes intersect can appear doubled-up on screen. This requires the use of selective focus (large apertures that reduce the depth of field) so that the doubled-up background will be sufficiently out of focus.
Shooting with parallel lenses avoids these problem and there are several ways to prevent the entire subject space from being rendered in front of the screen, into negative parallax: A stereo camera can be designed such that the distance between sensors (or between film gates) is greater than the distance between lens axes. It doesn't take much shifting to the outside of center to push the rendered space behind the screen, into positive parallax. Cameras have even been designed with variable-offset film gates, so that the placement of the stereo window along the Z-axis of the subject space can be varied at will. Even in the absence of such equipment, when using cameras where the sensor or film gates is centered behind the lens, a stereographer can still shoot with the lenses converged at Infinity (with the lenses parallel), controlling the placement of the stereo window in post, by cropping a narrow, vertical strip from each frame (to mimic having used a proper stereo camera design that has variable offset sensors or film gates). This solution, is unfortuntaely accompanied by a slight loss of resolution.) Still, it avoids the less pleasant side effects of shooting with converged lenses.
Michael K. Davis