Re: [pygame] Question about .bmp files and transparency

[SB <shandy@geeky.net>]

In GIMP, use Filters->Colors->Color To Alpha.  Choose black as the
color.  Then save it in a format that respects the alpha, like PNG.

-sjbrown

On Tue, 2003-09-09 at 04:44, Erlend Strømsvik wrote:
> Hi
> 
> Just started trying out Pygame and my first project is coming along
> nicely: A Tank Wars game. (Got to start somewhere ;)
> 
> To be able to create some nice explosions I thought I would use some
> images and 'throw' them around. For the images I already have some .bmp
> files which I took from another game. 
> Here is the problem though. These .bmp files are all with a black
> background, and all have their edges etc. antialiased against black. The
> game where the images are used the images black background turns fully
> transparent, then less dark pixels get some transparency and only bright
> pixels are none transparent.
> How this is done has me a bit puzzled. The .bmp images are 24 bit no
> alpha channel.
> 
> Could I just add together the RGB layers and create an alpha channel
> from those? Is that viable solution? Or how would -you- do it? :)
> I could always just use some transparent .gifs but the effects wouldn't
> be so nice then, with transparency only being limited to one color.
> 
> I'm also a bit unsure about how to use images with alpha channel or how
> to add an alpha channel to a image.
> 
> >From searching the in Internet I guess the term for this is 'alpha
> blending'? :)
> 
> 
> Anyway, I really like pygame. I've been using BlitzBasic earlier, but
> with pygame you much of the same functionality but with a much better
> programming language.
> 
> Also, I see now need for future support for older versions of python.
> 
> 
> 
> -
> Erlend Stromsvik
-- 
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| Shandy Brown                               Digital Thinkery |
| shandy@geeky.net             http://www.digitalthinkery.com |
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