[mapserver-users] Simple image compositing / alpha channel work?

[Stephen Lime]

Raster classes might be just the ticket. For example, say you're using DRG overlays.
You could just show vegetation by isolating the 'green' pixels and setting everything
else to transparent. Should work ok, but has not been used by many folks. If possible
use 3.5 so if there are problems we can fix them in the development source ASAP.

Steve

Stephen Lime
Internet Applications Analyst

Minnesota DNR
500 Lafayette Road
St. Paul, MN 55155
651-297-2937

>>> "Ed McNierney" <ed at topozone.com> 07/11/01 11:43AM >>>
Folks -

Has anyone done any raster image compositing or alpha channel work for
MapServer?  I've got a gray-scale shaded relief basemap image that I'd
like to use, initially with just another raster layer merged on top of
it, and I need some simple alpha support (or a reasonable substitute).
I'm starting with the OFFSITE parameter's all-or-nothing approach, but
before I dig in and start coding I figured I'd check to see if there's
any other applicable work out there.  Thanks!

	- Ed

Ed McNierney
Chief Mapmaker
TopoZone.com
ed at topozone.com 
(978) 251-4242