This directory contains a simple preliminary demonstration of 
SuperviseWindow used with an image. 
"demo" allows you to interactively query a pixel
location and color in an image. 
"demo1" allows you to specify with two picks the corners
of the image subset you wish to see.

Run either  'demo' or 'demo1', and when DX comes up, put it in 
execute-on-change mode.  

Pick using any mouse button.