Believe it or not, you don’t actually need 3D glasses to experience convincingly realistic 3D images (or movies). You just need to make yourself go “crosseyed”. Essentially, you look at two images, and by intentionally crossing your eyes to defocus your normal vision, the two images will converge into one central image that the brain will interpret as a 3-dimensional scene.
Note though that this is different yet similar to autostereograms, or “magic eye” pictures, whereby a computer combines two depth maps into a repeating pattern that varies slightly. It takes a lot less skill to view the cross-eyed types of images we will create today though.
Viewing Cross-Eyed 3D
Take a look at the image below. If you’ve never tried this before, the white dots help you to center the image correctly. Simply move both your eyes toward your nose until the dots converge on each other in the middle. The image should now “click into place” as your brain recognises that actually, these two pictures match up perfectly for 3D.
You don’t actually need the dots at all though – just blur your vision until the images magically slot into place. You can even extend the technique to videos; check out the following footage in YouTube cross-eyed format (if you’re not seeing it cross-eyed, click the 3D control button, and select “side by side” from the Change Viewing Method option).
A Note About Picture Formats & Terms
.MPO is a native 3D format, though some 3D camera manufacturers use their own standards to create incompatible files.
.JPS is a stereo-jpeg. It’s actually just two jpegs – side by side – like we will be creating today – but the special file extension allows 3D viewer applications to recognise it immediately as 3D content.
.JPG is the regular picture format we all know and love. You can rename a .JPS to .JPG and it will be viewable just the same; to use your .JPG as stereo jpgs, just too do the opposite and change to .JPS.
Anaglyph, or red-cyan, is an old 3D format that looks horrendous and messes up colors. It gained popularity in comic books of the 60’s and 70’s, but there’s no reason to touch this format today.
I won’t be touching upon 3D output and displays other than cross-eye today though. If you’d like to know if your PC is capable of viewing active or passive 3D, then please read my FAQ (TL;DR – it probably isn’t, and you’ll need to spend at least $500 on a new TV or monitor if you want it to be).
4 Ways To Make Your Cross-Eyed Stereo Pictures
Fake It (Photoshop)
This is one technique you could if you already have an image you’d like to “3D-erize”. We’re going to extract the various parts of the image and place them on their own layer so that we can manipulate them. I’ll be showing you with one object; you can use more if you like.
- Open the image in Photoshop and note the dimensions.
- Create a new image that’s the same height, but twice the width.
- Paste in the original image and align it to the right. Create a ruler in the center of the new double-size image to aid you in cropping and aligning things later.
- Working from the layer on the right side, select the object you’d like in the foreground (closest to the the viewer). In CS6, use a rough mask and then use the Refine Edge command to select the object in more detail.
- Output to a Selection, then copy and paste this selection to a new layer.
- Still with the selection active, click on the original image layer and remove the object.
- Fill in the background using the context-aware tool. Hide the object while you’re doing this. Obviously, this is going to work better on a scene with a repetitive background, like grass. Use Edit->Fill->Content Aware if the delete command has left you with a big white space.
- Now, you should have a background and a foreground layer. Duplicate them both, and align them on the left side of the screen. Set the foreground objects visible again if you haven’t already.
- The final step is to shift the foreground objects. Move the left hand object a little to the right, and move the right hand object a little to the left. If things start overlapping (beyond the mid point), delete that area.
That’s it! Stand back and try the technique. Admittedly, the end result is pretty poor compared to other methods outlined below, and you end up with an image that’s far smaller than the original you started with (relative to how much you’ve shifted the object toward the center). If you’re having trouble bringing the 3d image into focus at all, it means you’ve pushed them too close together. You’ll see I’m also floating because we’re only able to place the entire object onto the same 3D plane.
To get a larger final image, try to widen the original using Content Aware fills (again, this is only going to work with a consistent background). After widening the original and doing the above method again, I ended up with this:
I’ve used a real photograph of myself to demonstrate, but if you’re going to create imaginary scenes, the 3D effect will be more pronounced and effective due to the lack of external signals conflicting with the brain (we know a person should be a certain size, so our brain uses that to create a rough estimate of the distance away from us when creating the depth perception)
With a 3D camera
There are a few consumer-level 3D digital cameras out there, none of which is more popular than the Fujifilm Real3D W3, which I happen to own. It’s basically just two cameras in one, eye width apart; but the no-glasses needed viewfinder and fine controls over parallax are useful though.
Simply upload the image, and it’ll convert it for you. Don’t use this method for photos you want kept private though.
Here’s the full version of that image, if you’d like to see it.
With a single camera
Instead of buying an expensive 3D camera, just use your existing camera or phone to take two picture: focus them at the same subject, but for the second image physically shift the camera about 3 inches to the right. Again, just combine them in your favourite image editor by pasting them onto a new image that’s twice the width of the original. The first image should go on the left, and the second on the right (if you followed my instructions above, otherwise your mind will unable to combine them).
Here’s one I made earlier with my iPhone – the results are pretty good considering how easy it is to do this.
There’s An App For That
If you don’t want to mess around with image editors, 3D camera is a great little $1.99 iPhone app that outputs your results to a number of different formats. The intro screen explains the same basic principle – take the first photo, then shift the phone right. You can also align the images before output, which is nice.
Here’s the image I made in the screenshots above – that’s a ferret, by the way.
Making a 3D image is actually not as hard as you might think. Are you able to view the images correctly, or do your eyes just not “do 3D”? Apparently, around 10% of us can’t actually view 3D imagery correctly, so don’t be surprised if you can’t. If you can though: did you know you can actually play PC games like this? Just purchase some third party drivers from TriDef.com and select “side by side” as the output method.
Comments, suggestions? We’re listening!