[mapserver-users] 24 bit PNG transparent symbols

[Toni Pignataro]

Hello list,

Did any one solve this or have an idea, you Davide? I am having exactly 
the same problem, i am not getting the png image transparent.
I know to use the OPACITY, but this gives tranparency to the whole layer 
and is not what i need.
What i want is to set the color red in an png symbol transparent . I 
created this png in Gimp with an tranparent background and filled it 
with the color red (RGB 255,0,0)


My defined OUTPUTFORMAT  is:

OUTPUTFORMAT
     NAME PNG24
     DRIVER "GD/PNG"
     MIMETYPE "image/png"
     EXTENSION PNG
     IMAGEMODE RGBA
     TRANSPARENT ON
END

CLASS-section:

STYLE
            SYMBOL 'red'
            SIZE 100
            MINSIZE 100
            COLOR 255 0 0
END

Symbol-section:

SYMBOL
     NAME "red"
     TYPE PIXMAP
     IMAGE "red.png" 
     TRANSPARENT 100
END

So my questions are the following:

1. Due to the mapserverdocumentation it says for TRANSPARENT in the 
SYMBOL-section "[color index]". What does this mean?
2. The COLOR defined in the STYLE-section: is  this the color on which 
the transparency applies?
So her i would place 255 0 0, because this is my color where i want the 
transparency?


Thanks for any suggestions,
Toni P.


Davide Ticozzi schrieb:
> Hi List,
>
> I'have the same question posted by Ben Brehmer in the late 2008, but 
> nobody have given a response until now.
>
> I've been trying to get 24 bit PNG symbols to be transparent.
>
> I've tried both GD and AGG output. I've tried --with-experimental-png. 
> I've tried editing the symbol in photoshop to be transparent. 
> Basically fooled around with all the different output format options. 
> I've tried both RGB and RGBA png images.
>
> 8 bit PNG symbols work just fine. But the 24 bit symbols always have a 
> white and non-transparent background (see attached image).
>
> Is there any other mapfile configurations I can try before I convert 
> all of my 24 bit images to 8 bit?
>
> Or maybe this is a known bug?
>
> Thanks,
>
> Dave
>
> _______________________________________________
> mapserver-users mailing list
> mapserver-users at lists.osgeo.org
> http://lists.osgeo.org/mailman/listinfo/mapserver-users