Legacy ImageMagick Discussions Archive

Sorry for asking this seemingly straightforward question, but I've been trying for so long without success

I need to convert a 32-bit BMP to PNG, preserving the alpha channel. I thought this would be straight forward I've also tried varius parameters such as -channel argb and so on without success.
I have a bunch of bmp's I need to batch convert through code, and I've been trying all day to do this with varius tools.
Any thoughts and help is very much appreciated!

What version of IM? What platform?

Put your file somewhere like dropbox.com and paste the URL here.

try

Convert before.BMP PNG32:after.PNG

If you have an older format BMP, perhaps try

Convert BMP3:before.BMP PNG32:after.PNG

fmw42 wrote:If you have an older format BMP, perhaps try

Convert BMP3:before.BMP PNG32:after.PNG

The "BMPn:" prefix has no effect on the bmp decoder; it's currently only used by the encoder for selecting an output format.
Putting it in front of the input filename is harmless, though.