[josm-dev] JOSM Mappaint and PNG's without alpha channel

[Henrik Niehaus]

Dirk Stöcker schrieb:
> Hello,
> 
> a recent image ompimization of the mappaint icons showed that JOSM has a 
> strange behaviour related to the existence of an alpha channel.
> 
> a) If there is an alpha channel it is used for transparency.
> b) If there is no alpha channel, the background color is used as alpha channel.
> 
> Now the image optimizer removed the alpha channel for all icons, where is 
> empty and josm then switched to mode b which caused some ugly looking 
> icons.
> 
> The question is, how can I force it to handle "no alpha channel" 
> effectively as "no alpha channel" and not as "background color alpha 
> channel"? I did not really find anything related to this topic in the Java 
> docs.
> 
> Ciao

Maybe it helps to transform / load the image as another image type. Have
a look at the BufferedImage class. You can construct BufferedImages of
different types like TYPE_INT_ARGB and TYPE_INT_RGB.