I'm trying to reduce the file size of some images by converting them from true color to paletted. The problem seems to be those images have an alpha channel.
I'm using something like:
gm convert -colors 256 -type Palette in.png out.png
However, I'm getting the following error: convert: Can't write tRNS with an alpha channel (out.png)
PNG files can store an alpha channel even with paletted images, so I guess what I want to do should be possible with gm. Am I doing something wrong or is this something not (yet) supported?