Anaglyph 3D

Anaglyph 3D is the name given to the stereoscopic 3D effect achieved by means of encoding each eye's image using filters of different (usually chromatically opposite) colors, typically red and cyan. Anaglyph 3D images contain two differently filtered colored images, one for each eye. When viewed through the 'color-coded' 'anaglyph glasses', each of the two images reaches the eye it's intended for, revealing an integrated stereoscopic image. The visual cortex of the brain fuses this into the perception of a three-dimensional scene or composition. Anaglyph images have seen a recent resurgence due to the presentation of images and video on the Web, Blu-ray Discs, CDs, and even in print. Low cost paper frames or plastic-framed glasses hold accurate color filters that typically, after 2002, make use of all 3 primary colors. The current norm is red and cyan, with red being used for the left channel. The cheaper filter material used in the monochromatic past dictated red and blue for convenience and cost. There is a material improvement of full color images, with the cyan filter, especially for accurate skin tones. Video games, theatrical films, and DVDs can be shown in the anaglyph 3D process. Practical images, for science or design, where depth perception is useful, include the presentation of full scale and microscopic stereographic images. Examples from NASA include Mars Rover imaging, and the solar investigation, called STEREO, which uses two orbital vehicles to obtain the 3D images of the sun. Other applications include geological illustrations by the United States Geological Survey, and various online museum objects. A recent application is for stereo imaging of the heart using 3D ultra-sound with plastic red/cyan glasses. Anaglyph images are much easier to view than either parallel (diverging) or crossed-view pairs stereograms. However, these side-by-side types offer bright and accurate color rendering, not easily achieved with anaglyphs. Recently, cross-view prismatic glasses with adjustable masking have appeared, that offer a wider image on the new HD video and computer monitors. The oldest known description of anaglyph images was written in August 1853 by W. Rollmann in Stargard about his 'Farbenstereoscope' (color stereoscope). He had the best results viewing a yellow/blue drawing with red/blue glasses. Rollmann found that with a red/blue drawing the red lines were not as distinct as yellow lines through the blue glass. In 1858, in France, Joseph D'Almeida  delivered a report to l'Académie des sciences describing how to project three-dimensional magic lantern slide shows using red and green filters to an audience wearing red and green goggles. Subsequently he was chronicled as being responsible for the first realisation of 3D images using anaglyphs. Louis Ducos du Hauron produced the first printed anaglyphs in 1891. This process consisted of printing the two negatives which form a stereoscopic photograph on to the same paper, one in blue (or green), one in red. The viewer would then use colored glasses with red (for the left eye) and blue or green (right eye). The left eye would see the blue image which would appear black, whilst it would not see the red; similarly the right eye would see the red image, this registering as black. Thus a three dimensional image would result. William Friese-Green created the first three-dimensional anaglyphic motion pictures in 1889, which had public exhibition in 1893. 3-D films enjoyed something of a boom in the 1920s. The term '3-D' was coined in the 1950s. As late as 1954, films such as Creature from the Black Lagoon remained very successful. Originally shot and exhibited using the Polaroid system, Creature from the Black Lagoon was successfully reissued much later in an anaglyph format so it could be shown in cinemas without the need for special equipment. In 1953, the anaglyph had begun appearing in newspapers, magazines and comic books. The 3-D comic books were one of the most interesting applications of anaglyph to printing.