Hi folks
I've got a sticky WMS transparency problem I can't resolve. I'm serving
a WMS layer to another Mapserver instance for further display and having
very odd PNG transparency issues. The issue is that my layer appears in
their map with a colored but slightly transparent background (usually
green, purple, or red) . The features in my layer are not transparent,
just the background. The background color can vary upon map refresh.
Has anyone run into this colored pseudo-transparency before?
This remains the case when:
1. I serve an RGB PNG and they use an OFFSITE value.
2. I serve an RGB JPEG and they use an OFFSITE value.
3. I serve an RGBA PNG with TRANSPARENT TRUE on the my end and no
OFFSITE on the client end.
The only way to avoid this behavior is to set the client mapfile to
serve PC256 PNGs which causes rendering issue with the existing legends
in their application. However when my layer is displayed, the rendering
issues are minimized, when my layer is off, legend colors render
poorly. I've tried many different permutations of other image formats
on both ends, but these are really shots in the dark My version is MS
4.8.1 the client instance is MS 4.0.1 - they are also using
PHP/MapScript 4.0.1 to manipulate the mapfile for their UI, but I don't
see any image format changes in that code...
Thanks for whatever pointers folks might suggest!
Jesse
My relevant mapfile bits:
MAP
NAME ""
STATUS ON
EXTENT -79.069 32.643 -73.341 37.103
SIZE 666 500
SHAPEPATH "../data"
SYMBOLSET "../etc/symbols.sym"
FONTSET "../etc/fonts.txt"
IMAGETYPE PNG
DEBUG ON
IMAGECOLOR 255 255 255
OUTPUTFORMAT
NAME png
MIMETYPE "image/png"
DRIVER "GD/PNG"
EXTENSION "png"
IMAGEMODE RGB
FORMATOPTION "INTERLACE=OFF"
TRANSPARENT OFF
END
.....
Client mapfile bits:
MAP
NAME ""
STATUS ON
EXTENT -91.5 22 -71.5 36.5
SIZE 456 384
SHAPEPATH "../data"
SYMBOLSET "../symbols.sym"
FONTSET "../fonts.txt"
IMAGECOLOR 230 247 254
UNITS DD
IMAGETYPE PNG
OUTPUTFORMAT
NAME PNG
DRIVER "GD/PNG"
MIMETYPE "image/png"
IMAGEMODE PC256 # this works, RGB or RGBA do not
EXTENSION "png"
END
....
--
Jesse Cleary
Department of Marine Sciences
UNC Chapel Hill
17-6 Venable Hall
[EMAIL PROTECTED]
(919) 962-4323
