Andy's SIS Collection:
SISs (Single Image Stereograms) have always been fascinating to me as a visual scientist. So one day I decided to find out what their secret was and started to play around with random dots. The result of that is a very simple program that takes a depth map (in the form of a grey level image) and any background you like, and converts them into a SIS.
If you wish, have a look at a few examples below. Jump here if you are only interested in the final stage. For more stereograms and a lot of information on them check out Skal's SIS page or Gareth and Peter's SIRDS pages and the many links provided there. Heidrun's collection is quite extensive too.
[None of these sites are around any more, but today Wikipedia would be a good starting point.]
If you don't know how to see anything in Single Image Stereograms, have a look at the SIS viewing instructions.
If you have any comments or suggestions, feel free to send me an e-mail.
Click at a number in the picture above or choose from the menu: 1- Modified CVS logo 2- Unofficial RSBS logo (Research School of Biological Sciences) 3- Danger, bees! 4- Gabor 5- Maze; Find your way from the upper left to the lower right corner... 6- Escher's lizards 7- Escher's lizards on paper texture 8- Escher's lizards with superimposed SIM (Single Image Monogram)
I have also written a program that produces ASCII-Stereograms or SIRTS (Single Image Random Text Stereograms). They have the advantage that you don't need a graphical interface to appreciate them. Text stereograms are also very easy to analyse, if you are interested in the mechanism of SISs.
Note that ASCII-Stereograms only work with a fixed-width font (eg. Courier). Here are a few examples:
A BBBBBBB CCCCC DDDDDDD EEEEEEEE AAA BBB BBB CCC CCC DDD DDD EEE AA AA BBBBBBBB CCC DDD DDD EEEEEE AAAAAAA BBB BBB CCC CCC DDD DDD EEE AAA AAA BBBBBBBB CCCCCC DDDDDDDD EEEEEEEEE A- Centre for Visual Sciences (commented) B- Steps (commented) C- Happy Birthday! D- Landscape E- Affenschwanz
And then, finally, I worked out how to get rid of the discrete steps in depth, so the last few examples are grey scale images with nice, smooth surfaces. They are a bit boring in terms of composition and content; I just had to know that I can do it. Unfortunately I don't have the time for more...
10- Gabor again... 11- Cube 12- Smooth Cross 13- Christmas tree (two superimposed SISs)

