[gdal-dev] Hide OGR_STYLE from PDF attributes

[Jukka Rahkonen]

Jukka Rahkonen <jukka.rahkonen <at> mmmtike.fi> writes:

 
> I wonder also why the the example about using png images as symbols in the
> document http://www.gdal.org/ogr/drv_pdf.html includes  settings for the symbol
> color. OGR_STYLE in the example is SYMBOL(c:#000000,id:"a_symbol.png"). Does
> some of the supported image formats really support changing colors on-the-fly?


I can tell now that color can be used for adjusting transparency if alpha
channel is included too. The example it not the best possible because 
SYMBOL(c:#000000,id:"a_symbol.png") means the same as plain
SYMBOL(id:"a_symbol.png") and resulting symbol will be 50% opaque.
Perhaps the example could be edited a bit:
Alpha channel value controls the opacity/transparency 
SYMBOL(c:#000000FF,id:"a_symbol.png") makes 100% opaque symbol


-Jukka-