595 - 
Fig. 8 - The difference between the derivative applied to 
channel 3-5^. and the integrative function of channel 9-11^ 
emphasizeé the thermal texture of the surface investigated 
over the averaged radiance of the back-ground. 
Fig. 9 - Comparison between the normal thermogram (band 
9-11/x) and the image obtained by applying the derivative 
in module. In this case the result is the isogradients 
description independently from the scanning direction.