Color encoding (anaglyph) is the de facto method used for 3D over the years. In fact, there are many hundreds of patents on anaglyphs in a dozen languages going back 150 years. The left-eye and right-eye images are color encoded to derive a single merged (overlapped) frame; at the receiving end the two frames are restored (separated) using colored glasses. This approach makes use of a number of encoding processing techniques to optimize the signal in order to secure better color contrast, image depth, and overall performance (Fig. A3.1). Red/blue, red/cyan, green/magenta, or blue/yellow color coding can be used, with the first two being the most common. Orange/blue anaglyph techniques are claimed by some to provide good quality, but there is a continuum of combinations [31]. Advantages of this approach include the fact that it is frame-compatible with existing systems, can be delivered over any 2D system, provides full resolution, and uses inexpensive “glasses.” However, it produces the lowest quality 3D image compared with the other systems discussed above.
