FREEZE
------

Freeze is used to fix a colour
on the arrows, keeping the same
colours on the field limits.
OFF : 	when moving the arrows on 
	the colour map, the sliders
	will show the colour components 
	of the pointed field.
ON :	the sliders do no change. 
	The colours are frozen.

Example :
In (OFF) mode select a small region and 
it's color limits. Then click (ON) and 
move the arrows, enlarging the
region. Now click <middle> on mouse, 
the previous region colours will expand 
to fill in the new region. This method
is very practical to perform fast 
multicolour thresholding.
See Mouse information.



