What is an Anaglyph?

An anaglyph or stereoscopic image is an image in which the illusion of depth is produced by offsetting two copies of the same image in two different colors. Anaglyphs are commonly known as “3D images” and are routinely used for entertainment, science, and medical purposes.

How Anaglyphs Works

Anaglyphs work by layering two separate copies of the same image so that the left eye sees one copy and the right eye sees the other. While the two images are layered on top of one another, they are always in different colors in order to provide contrast for the brain. This tricks the brain into seeing one image slightly behind the other, causing a viewer to see a three dimensional image. However, in order for a person to see an anaglyph as three dimensional, he/she must be wearing anaglyphic glasses. Anaglyphic glasses have a thin layer of colored plastic over each lens, matching the colors of the anaglyphic image itself. Anaglyphic images and glasses generally use red and cyan as their primary and secondary colors. Of the entire light spectrum, these colors have the most contrast.

Applications

Many modern video games and movies now use anaglyph images to create depth perception and cause the image to seem much more realistic than it actually is. Some Internet content now includes anaglyphic images. Anaglyphs also recover three dimensional images of the Sun, produce 3D models of micro-organisms and chemical bonds, and are used in both Google Maps and Google Earth in order to allow users to view streets in 3D.

Advantages

Anaglyphs can be printed anywhere regular images are, allowing them to be used in books and on websites. They are also relatively easy to produce and can be created from any image. In fact, 3D movies are simply a long series of anaglyphic images.

Disadvantages

Although anaglyphs are advantageous, they do have the disadvantage of requiring anaglyph glasses in order to be seen. Without these glasses, an anaglyph appears to be a blur of red and cyan.