[magick-users] Conversion of tga to bmp results in a black box

[Alastair Gregory]

Hi,
I'm converting a number of .tga images to Windows bitmaps.  The command

convert foo.tga foo.bmp

works fine most of the time, however for some files the result foo.bmp 
is just a black rectangle of the appropriate dimensions.   The input 
images (.tga) look fine, and another image conversion utility (ACDSee) 
has no problem converting them to Windows bitmaps.  Furthermore, the 
.tga files can be convert'ed to TIFF successfully, so it looks like the 
problem must be something to do with the way the .bmp format is being 
output.

Is there something I need to specify on the command line to make this 
conversion work 100% reliably?  It's odd that this issue only affects a 
small percentage of the input files.

Thanks in advance,
Alastair