[mapserver-users] How to make label background transparent?

[lars.schylberg at blixtmail.se]

Hi Steve,

I am not sure what your use of IMAGECOLOR has to do here.  Normally I have some layers in between the 
background and the elevation lines.

But there are two more ways do get the color to be transparent in Mapserver:

STYLE
  GEOMTRANSFORM 'labelpoly' 
  COLOR "#ffffff00"
END

or 

STYLE
  GEOMTRANSFORM 'labelpoly' 
  COLOR 255 255 255
  OPACITY 0
END


But those are doing the same thing as your solution below with COLOR -1 -1 -1

Maybe You are after some of the potential techniques that Thomas talked about a couple of years ago with
layer blending with the label cache. Those were some future techniques that could be added to the
layer composite pipeline if anyone was interested. 

Best regards

Lars Schylberg