The Wonderful World of Electronic Imaging • University of Ottawa Enrichment Mini-courses Program 2014 • Stereoscopic Imaging • How do we see in 3D? • How can we reproduce 3D images?
Seeing in 3D • What do we mean by 3D? • Answer: 3D = three dimensions • Height • Width • Depth height depth width
Making 3D Pictures • Over the centuries artists learned to represent the three-dimensional (3D) world in their pictures using perspective and other cues. • More recently, computer graphics can do the same thing. However, the pictures are still FLAT!
Binocular Vision We see the world with two eyes. Each eye sees a slightly different view of the scene we’re looking at. The brain interprets the differences and provides us with the 3D perception of depth.
We see with two eyes
Stereoscopic Imaging • Form two images of the scene from slightly different points of view -- either with a camera or by computer graphics • Display the two views with some device that forces the left eye to only see the left image and the right eye to only see the right image
A Stereoscopic Imaging System Scene Stereoscopic camera Viewer (with glasses) Stereoscopic display
Argus Stereo Camera Viewer
How to display stereoscopic images electronically? • Polarizing filters • Time alternating shutter glasses • Colored glasses (anaglyph) • Lenticular screens • Parallax barriers • Holograms
What is ‘anaglyph’? Anaglyph is a method to view stereoscopic images using cheap coloured spectacles. It was invented around 1850. Anaglyph is a Greek word.
The basic idea For monochrome (no colour) stereo images, the left view in red is superimposed on the same image with the right view in blue. When viewed through spectacles of corresponding colors, the three-dimensional effect is perceived.
The Anaglyph stereoscopic images in this presentation require the red/blue glasses available in this room to perceive the 3D effect.The red filter goes over your LEFT eye. RIGHT LEFT
CAUTION • It is said that about 10% of people don’t perceive the stereoscopic 3D effect. • Some people may feel queasy when viewing 3D images. • If you’re in the first group, you may find the 3D images in the presentation rather boring. • If you’re in the 2nd group please don’t feel obliged to look at the images with the glasses!
Three main types of anaglyph glasses • Red-cyan • Green-magenta • Blue-yellow
On April 17, the National Air and Space Museum premiered Space Station, a 3-D IMAX film that takes viewers aboard the International Space Station, orbiting some 220 miles above Earth. Twenty-five astronauts and cosmonauts from the United States, Canada, Japan, Russia, and Europe shot more than 12 miles of 65-mm film between December 1998 and July 2001; Space Station features 3-D sequences shot during the construction of the ISS, as well as zero-G glides through the station's interior.
How do we make a color anaglyph? • We use the properties of the glasses as filters of the wavelengths of light. • We use the properties of the light emitted from thedisplay • We use the properties of the cones in the human eye • We use mathematics to find the best anaglyph image that will look most like the ideal stereoscopic image when viewed by a human looking at the display through the glasses
More stereoscopic images https://www.flickr.com/photos/e_dubois/sets/72157606640245479 https://www.flickr.com/groups/anaglyph/ http://adcnj3d.wordpress.com/the-science-of-anaglyph-3d/
Steps to make a stereoscopic anaglyph Place camera on the slider on a tripod. Take the left view, slide the slider, then take the right view. Download the two images to the computer. Run StereoPhoto Maker Choose File/open left/right images… and load the two in that order. Select Adjust/Easy Adjustment … Adjust H position and V position until the preview looks good with the stereo glasses and click OK. Select Stereo/ Color Anaglyph/Dubois and view. If the result is good, you can save as jpg
Have a Happy Colorful Three- dimensional Summer!