Re: [udig-devel] export map to image bug

[Graham Davis <gdavis@xxxxxxxxxxxxxxx>]

Jody Garnett wrote:
> >  I'm assuming it is alright to fix this bug by simply
> > changing that?  Are there any reasons that a png or other format would need
> > to be saved from a bufferedImage with alpha support?
> >     
>
> If you wanted to export an image that would be combined with others on
> a web page; or even if you just wanted it transparent for copying into
> a paint program or word document?
>   
Well the PNG is still generated correctly, and the image still supports 
alpha if you want to edit and add alpha data in another program - it 
just doesn't have any alpha data currently in it.  And I'm pretty any 
image exported from uDig has no alpha data in it since there is no alpha 
data to write (the image is just a composite rendered by the uDig map 
renderer, does it ever render in any true alpha transparencies?  I was 
under the impression it took transparencies into account when rendering, 
but the resulting composite was always just a regular non-alpha image).

I did look at the ImageIO library to try and find a way to determine 
what formats support alpha with the writers and readers, but I couldn't 
without first providing it an image (which would already have to be 
built with alpha or no alpha).  So that put me back at square one.  I 
will make sure the map renderer is properly setting the background 
color.  What is the "non-native" jpeg writer you are referring to?

--
Graham Davis
Refractions Research Inc.
gdavis@xxxxxxxxxxxxxxx