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problems converting 32bit bmp with alpha to 32bit tga

Posted: 2008-05-20T20:00:28-07:00
by ricgreen1
Whenever I try to convert a 32bit bmp with alpha to a 32bit tga with alpha, the alpha channel gets set to white instead of the alpha channel that is present in the source bmp. I tried all kinds of settings including

convert -matte -depth 32 c:\photo.bmp c:\photo.tga

and nothing seems to work :(

The bmp was created using photoshop cs3

Thanks!

Re: problems converting 32bit bmp with alpha to 32bit tga

Posted: 2008-05-20T20:34:13-07:00
by fmw42
try

convert <inputimage> -channel RGBA -matte <outputimage>

Re: problems converting 32bit bmp with alpha to 32bit tga

Posted: 2008-05-21T11:02:47-07:00
by ricgreen1
Unfortunately that gave me a white (blank) alpha as well. none of the alpha info ended up in the tga. :(

Re: problems converting 32bit bmp with alpha to 32bit tga

Posted: 2008-05-21T12:10:50-07:00
by fmw42
The only other thing I can think of is to use -compose copy_opacity -composite

see
http://www.imagemagick.org/Usage/compose/#copyopacity