I need the ability to be able to display ECW and JPEG2000 format files within MapServer via a Community Mapbuilder client which sends WMS requests for the images to MapServer

[Frank Warmerdam]

John Mitchell wrote:
> Frank,
> 
> The ECW is already in a compressed format, so this means that the image 
> is compressed another 95%?  This additional compression is for 
> performance purposes?; does it affect the image quality?

John,

The imagery is decompressed within mapserver for rendering purposes, and
then (if output is to ecw) re-compressed.  So the 95% is relative to
uncompressed form, not cumulative.   Even if the original image was
at 95% compression the process of decompressing and recompressing can result
in additional image damage.

Best regards,
-- 
---------------------------------------+--------------------------------------
I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | President OSGeo, http://osgeo.org