Single-Lens Anaglyph Capture

H. G. Dietz
http://aggregate.org/hankd/

Department of Electrical and Computer Engineering
Center for Visualization & Virtual Environments
University of Kentucky, Lexington, KY 40506-0046

Initial release: Not Yet!


This document should be cited using something like the bibtex entry:

@techreport{ancap20100818,
author={Henry Gordon Dietz},
title={Single-Lens Anaglyph Capture},
month={Aug},
year={2010},
institution={University of Kentucky},
howpublished={Aggregate.Org online technical report},
URL={http://aggregate.org/DIT/ANCAP/}
}


Would you like to be able to capture "3D" images using your current film or digital, still or movie, camera? Got $1? The anaperture CGI is an interactive WWW tool for creation of the special dual-aperture discs that we propose for single-lens anaglyph capture.

An anaglyph is a type of stereo image in which the left and right sides are encoded in a single image by assigning approximately non-overlapping colors to each side. Although many color assignments can be used, the most common are red/cyan and green/magenta. The image at the top of this page is a green/magenta anaglyph. To see depth, you use viewing glasses that have color filters causing each eye to see only the colors assigned to that side's view.

Normally, two separate images are captured and then processed together to form the anaglyph. Instead, we can directly capture the image as an anaglyph by using filters cut from cardboard-frame viewing glasses of the same colors used for viewing. This will wreck a pair of glasses, but they cost no more than $1. Alternatively, you can use photographic or stage lighting gel filters; stage lighting gel samples are cheap and generally come with graphs of the measured spectral transmission.

The two colors normally would be placed in front of two separate lenses, however, it suffices to create two optical paths within a single lens. This is done by a type of dual Waterhouse Stop -- a fancy name for a piece of dark paper or cardboard with two holes in it. If the holes are sized and placed correctly, and the appropriate filter is placed over each, capturing an anaglyph image is as simple as placing this new stop in front of the lens and pressing the shutter button.

The hole size and placement are critical, and depend on some properties of the lens. The anaperture tool accepts a few key parameters, computes the ideal stop design, and generates a Scalable Vector Graphic (SVG) image of the stop for printing. Laser or inkjet print the stop image, tape color filters over the holes, cut it out, stick it in front of your lens, and capture some anaglyphs!


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