Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ncar!noao!arizona!naucse!rrw
From: rrw@naucse.UUCP (Robert Wier)
Newsgroups: comp.graphics
Subject: Re: 3-D perceptual abilities
Summary: solving puzzles
Message-ID: <1188@naucse.UUCP>
Date: 6 Mar 89 03:50:59 GMT
References: <207400002@s.cs.uiuc.edu>
Organization: Northern Arizona University, Flagstaff, AZ
Lines: 23



 The technique of fusing two images into a stereoscopic
 image while not converging your eyes can lead to an amusing
 capability.  I first learned this technique when I became 
 interested in stereo photography, and got to where I could look
 at the old stere-optican cards without using a viewer.  I discovered
 that the same thing could frequently be done with the puzzles that
 sometimes appear in newspapers wherein a cartoon is repeated two
 times, and the reader is to find 6 (small) differences in the 
 drawings (or 5, or 7, ... whatever).  It seems that the cartoons
 are usually an exact match in places where the differences have
 not been intentionally introduced (I assume one original drawing
 is made, and then some changes are introduced to arrive at the second
 one).  By fusing the two drawings together, the areas of difference
 literally leap out of the page at you.  I have a number of times
 used this technique and amazed people by circling all the differences
 in the cartoons within 10 seconds, while everyone else took several
 minutes.  Give it a try the next time you see one of these puzzles.

   - Bob Wier                                College of Engineering
  Flagstaff, Arizona                      Northern Arizona University
  ...arizona!naucse!rrw |  BITNET: WIER@NAUVAX | *usual disclaimers*