Sorry for the delay in this posting, I have just fixed my modem after it
got fried in a thunder storm.
Thanks to Adam Brown, John Tobin and Scott Simmons.
Question.
Is there a script or some programme that can reduce Imagine files to
JPEG, (aerial photographs)  I have used the Mr Sid decompression (Lizard

Tec) for other files but have been unable to reduce Imagine files to an
acceptable definition.

Adam suggested Erdas Imagine, unfortunately we do not have it 'yet',
John mentioned the ECW compressor from 'ermapper.com'.  Works well but
not compatible with most input forms.  But have just noticed that
'Mapmaker' can now utilize it, so it is worth a try.  Scott suggested
ViewFinder from ERDAS, free, a very nifty little piece that fully done
the trick.  You need to go to Tiff first but it offers other options
that are worthy of some thought.
The plus of it all is that it reduced an Imagine, or Tiff file from 198
Mb to 5.6Mb with no loss of definition at 600 dpi or to 2.5Mb at 300
dpi, the scanned resolution anyway. (no DEM values) but for 2D
visualization a fantastic reduction in memory and in viewing and
panning.
Thanks again.
Jimmy