batch converting PNG icons to XPM

[Haim Ashkenazi <haim@consonet.com>]

Hi

I'm trying to convert many PNG icons (with transparency) to xpm with
transparency to use as icons with application that doesn't support png
(tkdesk). I tried to find a 'mogrify' or 'convert' option to keep the
transparency but nothing works. every time I'm converting an image the
transparent pixels becomes grey. I don't want to use the '-transparency'
option because that would change all the pixels that use this color.
any ideas? (of course I'm looking for a command-line application, not
X...)

btw, some of the png files have transparency that xpm doesn't support
(xpm only supports on/off bits) so I'll use the default 127 threshold
(the default when converting with gimp).

Thanks in advance
--
Haim