[Mapserver-users] Transparent symbols

[David Mitchell]

I am having trouble placing symbols with transparency on my map. When I 
try and put them on the part of the image that is transparent shows up 
as white. I have a symbol defined as:

	SYMBOL # Interstate
		NAME 'interstate'
		TYPE PIXMAP
		IMAGE 'symbols/interstate.png'
		TRANSPARENT 0
	END

This is in my symbols.sym file. The interstate.png is an indexed png 
with alpha channel (although I have also tried a 24-bit PNG). How do I 
make this symbol transparent? My mapfile looks like this:

MAP
	IMAGETYPE png
	OUTPUTFORMAT
		NAME png
		DRIVER "GD/PNG"
		MIMETYPE "image/png"
		IMAGEMODE RGB
		EXTENSION "png"
	END
	SIZE 916 793
	STATUS on
	UNITS dd
	IMAGECOLOR 181 199 214
	FONTSET "fontlist.font"
	SYMBOLSET 'symbols.sym'

	LAYER
		DATA "highway_shields"
		TYPE annotation
		STATUS default
		
		LABELITEM "highway"
		CLASS
			COLOR 0 0 0
			SIZE 18
			SYMBOL 'interstate'
			LABEL
				COLOR 255 255 255
				FONT arial
				TYPE truetype
				SIZE 7
				ANTIALIAS true
				POSITION cc
			END
		END
	END
END

-- 
David Mitchell
Software Engineer
Telogis

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