What is Stereogram

  What is a Stereogram? A stereogram is a picture, which becomes three-dimensional, if you look at it in a certain way.
  The feeling of "depth" that you get by looking at a statue instead of looking at a photo of the same statue, is due to the fact that the human body has two eyes.
  The 'brain' can make mistakes in this process of designation of pairs! It is that which make possible the 3-D feeling that we get from stereograms, as shown below.


Figure 1 shows a general picture. But in figure 2,you should be able to see the same point 'A' or 'B' but "somewhere behind" the picture.