3D Images
by Sunny
2008-07-09
To view the 3D images correctly, you need to wear a special glasses. The glasses has the red color on the left, and the blue color on the right.
How to make the 3D images?
1. Take 2 photos using tripod. The subject should stay still, and it should contain some depth. Take the first photo as what you see with your left eye, and then move your camera to the right about 2 inches (about the distance between your two eyes). Take the second photo as what you see with your right eye.
2. Edit these two photos in the photoshop.
3. Convert both photos to grayscale, and convert the second photo back to RGB mode.
4. On the second photo, go to channels mode, and select the Red channel only.
5. Copy the first photo, and paste on the second photo.
6. Select the RGB channel. This replace the Red channel of the second photo with the first photo.
7. Move the red layer around so that the two line up.
8. It is ready to see using the 3D red-blue glasses. It should be easy when you are actually doing it.
The final 3D image
Another example:
The 3D image
How 3D pictures work (Copy from Goolgle)
What see your eyes
When you make a 3D picture (stereogram) you use one important feature of human eyes - every eye sees a different picture. The difference depends on the distance of every object on the picture from the head of the observer. We won't do a long explanation - let's make a short experiment instead. Take anything to your hand - for example a pen.
Well, you have a pen in your hand. Point it up. Give it before your eyes to a distance to see it well. Now take a look at any object behind the pen – for example at a computer monitor or at a cup of tea on the desk. The pen should be in the distance about 6 inches from this object.
Close your left eye and shift the pen to place it in a position which you can easily remember. For example before an edge of the monitor. And now open your left eye and close the right one. Do you see the difference? If you did the experiment carefully, you could see the pen shifted to the right (but it hasn't moved really). No success? Try it again.
From our experiment we can see the left eye sees things, which are in front (for example in front of the edge of the monitor), a little bit more to the right than the right eye. And the things at the back a little bit more to the left (you can try to position the pen behind the edge of the monitor). How to use it for creating a 3D picture? If you have one photo from the point of view of the left eye and one photo for the right eye then the only thing you have to do for 3D is - to deliver every photo to it's eye. How? You can merge the photos in a special way and then to watch them through a special glasses (because without the glasses every eye sees the same).
Blue-Red glasses
The most affordable glasses you can use for watching stereograms (3D pictures) are glasses with red-blue (red-cyan) slides. The glasses you can get here for free. How the glasses work?
If you give the glasses before your eyes (red slide before the left eye, blue slide before the right one) then you can see this: left eye sees the red world and the right eye the blue world. But it isn't all. There is one more important thing. If something is red (for example a red cup on the white desk) then the left eye almost can't see it (it sees the red cup on the red desk), right eye sees it as dark. Similarly the right eye doesn't see the blue (blue-green) things. If the background isn't white then the situation changes - but the basic princip is the same - different eyes see different things.
And that's all the trick. If you take your photos for the left and right eye and use only their red or blue (bluegreen) part and then mix it then you get the stereogram (3D photo). When you use the glasses every eye sees only the part of 3D picture which has to see. But how to do this?