//*  Michael Cammer  cammer@aecom.yu.edu
//*  16 Aug 2004
//*  
//*  A very simple way to create masks and to see most of the raw data at the same time
//*  is to trace directly on the raw data.  But to do this, you must guarrantee that none of
//*  the pixels in the images will be the same as in the mask.
//*  This macro compresses the three brightest pixel values of 8 bit grayscale images
//*  into one pixel value, the third possible brightest.  The darkest three values are compressed
//*  into the third darkest value.  
//*  Why do this at both ends?  To avoid problems of MacIntosh vs. PC byte orders.  
//*  After running this macro, you may now trace using the fill, cut or clear commands.
//*  Just make sure that the tracings are pure black or pure white.
//*  In numbers, make sure that the tracings equal zero or 255.
//*
//*  Step 1:  Optional:
//*                 Adjust the brightness contrast the way you like it.  Use the Apply button
//*                 in the brightness/contrast window.
//*  Step 2:  Run this macro.


macro "Prepare for tracing in white or black [q]" {
  n = nSlices();
  run("8-bit");
  for (a=1; a<=n; a++){
    run("Set Slice...", "slice="+a);
    changeValues(253,255,253);
    changeValues(0,2,2);
  }  // for a
  run("Colors...", "foreground=white background=white selection=cyan");
  exit('Save the timelapse with a new file name and have fun tracing!');
}  // end Prepare for tracing in white or black