**CIGAL Reference Manual, Chapter 3 (Functions): STEREOGRAM**
===== STEREOGRAM -- Convert a Z-value image into a 3-d stereogram =====
**        usage: newimage = stereogram(Zimage,RPT,flag,zscale)**
          STEREOGRAM converts a Z-value map into a stereogram by calculating how
      the view from two different positions would distort the apparent Z-value
      surface, and then applying those distortions to a background image to
      create a 3-d stereo pair.  The Z-value map is specified by the ZIMAGE
      argument, which must be a 2-dimensional matrix.
      The background image is specified by the RPT argument.  It can be either
      an image or a number.  If it is an image, that image will be used to create
      the background. The image must have the same vertical (Y) dimension as the
      ZIMAGE. The horizontal (X) dimension of the RPT image is used as the stereo
      repeat interval.  If RPT is specified as a number, then that number is used
      as the stereo repeat interval and the background image is automatically
      generated as a random dot pattern (of dimension RPT x Ydim_of_ZIMAGE).
      The stereo repeat interval determines the size and appearance of the new
      image that is to be created. NEWIMAGE will have the same Y dimension as
      ZIMAGE and its X dimension will be the X dimension of ZIMAGE plus the
      repeat interval. This means that if the repeat interval is greater than or
      equal to ZIMAGE's X dimension, the output will contain two separate views --
      a standard stereo pair.  If the repeat interval is less than ZIMAGE's X dimension,
      the output will be an autostereogram in which two views of the 3-d object are
      superimposed in a repeated pattern of background images.
  
   The FLAG argument can be used to specify drawing options (combine by addition):
  1  - place a dot at the bottom of each view (separated by the repeat    interval)
  to help in fusing
  
  2  - don't fill in holes created by shifting pixels. Pixels in-holes will
  be assigned the values 1 or 2, depending on whether they are visible to
  only the left or right eye, respectively.
  
  4  - don't hide surfaces that would be masked by protruding objects
  By default, FLAG is 0.
  
  The ZSCALE argument is a scaling factor that is applied to every pixel in ZIMAGE.
  It is normally 1.0 but can be changed to adjust the size of the entire object.
  
  Note: To create a single stereo-image in which the two views are overlaid in different
  colors you would use stereogram to first create two separate views (i.e., with a stereo
  repeat interval equal to ZIMAGE's width) and then map the two views to the two different
  colors and superimpose.
**See Also:**\\


[[jvs:cigal|CIGAL Home]], 
[[jvs:cigal:manual|CIGAL Manual]], 
[[jvs:cigal:manual:chapter3|Functions List]], 
[[jvs:cigal:manual:help|Manual Help]]