Making a Full-Colour 3D Anaglyph

(Link to Assignment is at the bottom – please read all of this first)

 

The ability of our eyes and brains to see in three dimensions is due to depth perception.  Depth perception comes from many cues, such as diminishing size and light value as distance increases.  But the most important cue for humans comes from the fact that our left and right eyes look at the same scene from slightly different angles.  Our brains integrate the two images into one seemingly 3D image.

If you’re not sure about this, try closing one eye and walking around a room.  You’ll likely find it a bit harder to judge how far away objects are.

 

There are many schemes to mimic what our eyes do, none of them as good as the real thing!  They usually involve taking “stereo pairs” of pictures from slightly different angles.  But how do you combine them onto one print or screen and still retain the depth info from both images?

Our technique starts by removing the blue hues from one image and the reds from the other.  They’re then combined in a way that looks confusing and shadowy to the normal eye.  But when a red filter is placed over one eye (the right) and a blue filter over the other, suddenly our brains see two images through each eye separately, and integrate them into a 3D whole.  It’s not perfect, but it’s an interesting medium to explore.

Steps

1. Compose your photo carefully, considering the following:

  • As always, use your artistic eye to create an engaging image
  • Make sure it has lots of depth – clearly defined edges that move toward and away from the camera
  • Go for maximum depth of field, so really close objects are in focus as well as further ones
  • Focus to about the middle of the closest and furthest part of your subject
  • Whites, light browns, yellows and grays work better than blues and reds
  • Shoot the first image, and carefully move to the right, not very far, about 10 cm for close-ups, just enough to change the point of view as your 2 eyes would see it.  Once you get good at it, experiment with different separations.
  • Make sure you focus on the same spot for the 2nd image, and maintain the same height, angle etc.  A tripod really helps!

 

2. Now, import the 2 images into PhotoPaint (not PhotoShop).  Use the Window menu to tile them vertically (side by side), right eye image on the right.

 

3. In the right image, open the Channels window (Window, Dockers, Channels).

4. Select all (Ctrl-A).  Click the Blue channel.  The image will look gray, as shown.

 

5. Press the Delete key.  The image will look white, and the Blue icon will go solid.

 

6. Click “RGB Channels”.  The image will look gray-blue.  Copy it into memory (Ctrl-C)

 

7. Do the same steps for the left image, but make it red.  i.e.  Select All (Ctrl-A), click on the Red channel, Delete, Click RGB channel

 

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8.  Maximize the red image.  Open the Object window (Window, Dockers, Objects).

9.  Paste (Ctrl-V).  You’ll see only the blue image on top for now.

10. Change the merge mode from “Normal” to “Red”, as shown below.  You’ll see the first red & blue version – almost there!

 

11. Zoom in to a spot in the background.  Move the top image until some well-defined object lines up perfectly.  I chose a knob on the chair spindle:

                       

 

Not aligned:

Moved so the knob is aligned.  Other objects will not be aligned – that’s okay!

 

That’s it!  Save in both PhotoPaint and JPEG format, and then do a full-screen view (F9)

Put on your trendy 3D glasses (red right, blue left), and enjoy your creation!  Moving your head left and right helps you see the 3D effect.

Assignment & Evaluation