MS Truecolor output produces wrong colors with WMS-client layers.

[llo@…]

Rendering a single layer(ortofoto) into truecolor image works fine.

Adding a shapefile line layer also works fine.

Adding a wms-client line layer produces strange colors - it seems that the
transparent color of the layer is not handled properly.

This has been observed on version 4.0, CVS (15 oct. 03) on both win32 and linux.
using mapsever CGI.

[fwarmerdam]

Lars, 

Substantial additional information would be necessary to reproduce this problem.
Ideally a minimal map file and supporting data to reproduce the problem. 

I have encountered WMS servers which return .gif's without the transparent
value properly marked.  In some of these cases it may be impossible to 
"generally" identify the transparent color.  To the best of my knowledge
MapServer does not currently take advantage of the ability to request a particular
color to be used for the transparent color in the WMS client support.  This
might be a good avenue to pursue to resolve transparency issues with some WMS
servers.

[llo@…]

I finaly got time to reproduce the error in a simple setup.

The used mapserver is version 4.0 runing on a Linux bux using RedHat 7.1,
but i have found the problem on many mapserver versions supporting
true-color.

The complete setup can be found on the following URL:
http://software-dkplan.carlbro.dk/ms_truecolor_error.tgz

Note that U must change the URL, map.imagepath, map.layer.taster.data & 
map.layer.wms_green_polygon.connection to match a different setup.

The output_images catalog contains 4 files:

ok.jpg created with the following URL: http://gis4-llo/scripts/mapserv.pl?
service=error&mode=map&layers=raster+green_polygon 
where layer green_polygon is a local layer.

err1,2 & 3.jpg is all created with the following URL: http://gis4-
llo/scripts/mapserv.pl?service=error&mode=map&layers=raster+wms_green_polygon
where layer wms_green_polygon is a wms layer (from same .map file)

Note that fetching the image several times produces different images !

I hope that this will help U to track down the problem.

Regards Lars Loldrup.

[dmorissette]

Adding Frank to the CC.

[fwarmerdam]

Lars reports this has been corrected in testing with MapServer-4.4.0-beta2.

Closing.

I appologise for not having ever dug in deeply enough to reproduce it!