How To For Your Daily Life

Intro

Since settling in on the red planet, the Mars Exploration Rovers Spirit and Opportunity have sent back a number of 3-D postcards to countless fans outfitted in red- and blue-tinted spectacles. To some, the realistic pictures of the rocky martian terrain may seem magical, but the concept behind the illusion is in fact quite simple.
"Basically, 3-D pictures trick your brain into doing what it does all the time in the real world," says Zareh Gorjian, a graphic artist at NASA's Jet Propulsion Laboratory who makes 3-D pictures and animations of Mars for a living, both the black-and-white kind and the more advanced color versions.
So simple is the trick that, with a little effort, anybody with a camera, a computer equipped with photo-editing software, and a pair of tinted glasses can make their own 3-D pictures of Mars, family members, pets or anything else worth placing in front of a lens.
Gorjian, who has been toying with the technique for 10 years, transforms all sorts of pictures into 3-D feasts for the eyes, including his latest vacation photos. "It's just fun," he says.
The key to 3-D imaging lies in simulating a left and right eye. For the Mars Exploration Rovers, this is accomplished with the aid of a left and right camera eye. Images from the rovers' stereo camera lenses (either the hazard-avoidance cameras, the navigation cameras or the panoramic cameras) are tinted in red and blue, then merged into one blurred picture, which pops off the page when viewed through a pair of red- and blue-tinted glasses.
"Your brain thinks it is seeing two separate left and right images and so does what it always does -- combines them into one picture," says Gorjian.
These basic 3-D photos are called anaglyphs and work best when viewed in black and white. Color anaglyphs are trickier because red and blue objects appear only to one eye. "You give up full color when you use the red and blue glasses," says Gorjian.
Instead, he and his colleagues at JPL's Multimission Image Processing Laboratory create 3-D color photos using two sophisticated techniques: polarization and infrared-transmission. In polarization, the light from left and right eye images is polarized, or made to travel in opposing, perpendicular directions. In infrared-transmission, left and right eye images are flickered back and forth on a special screen faster than an eye can blink. Both strategies require specialized glasses for viewing.
But black-and-white 3-D images do not require fancy tools or equipment and can be snapped and clicked into being by following these directions recommended by Gorjian:

Video Tutorial

How to make 3D Anaglyph Images using Photoshop

The Process

Step 1 - Picking The Subject

Start out by picking a subject. People are a good place to begin because they tend to pop out in 3-D photos. Place the subject in a setting with a lot of angles and depth (not in front of a flat wall), and about 10 to 15 feet from the camera. Hold the camera steady by securing your elbows in your chest and snap a picture. Make sure your subject stays very still, then step just a tiny bit to the right, about the distance between your eyes or less, and take the same picture. When you slide over for the second shot, you -- and most importantly your camera -- should move in a parallel line. Note: If Mars is your subject, the pictures have already been taken for you. Scan through the raw images on the JPL web site http://marsrovers.jpl.nasa.gov and pick out left and right eye images for your favorite photo (only images taken by the rovers' navigation cameras, hazard-avoidance cameras and panoramic cameras come in pairs). The stereo images will look identical, but you can tell if an individual image is from the left or right camera eye by clicking on it and looking at the file name displayed in the web address bar. Left camera eye image file names will contain the letter "L" four characters in from the end, and right eye image file names will similarly carry an "R." Two raw image examples can be found at

This series of screenshots illustrates the steps outlined in the story describing how to make 3-D images. The images used here are Gorjian and his fiancé's Hawaiian vacation photos.

Step 2 - Open Images In Editor

The next step involves transferring the images into photo-editing software. Any program will work as long it allows for red, blue and green color channels to be manipulated independently. The following instructions will refer to Adobe Photoshop. If your pictures are digital, just open them up in the software. If your pictures are hardcopies, transfer them to a computer using a scanner, or drop them off at a photo-developing store and ask for digital files (any file type will work).

Step 3 - Remove Color

Once the left and right eye pictures are open, convert them both to grayscale by clicking on the 'Image' menu bar and selecting 'mode' then 'grayscale'. Next, assign the left eye image red, green and blue channels by going back to the 'Image' menu bar and selecting 'mode' then 'RGB' (the image will still appear gray). Do not repeat this step for the right eye image.