[Image-SIG] PNG and compression

[Bryan Willett]

I'm using PIL to create maps for my game:

merchempires.sourceforge.net

I don't know anything about the technicals of image file formats. I
want my maps to have the smallest image file size as possible. The
pngs that PIL creates are not as small as the pngs that I can
create with the GIMP.  I can open a png created with PIL in the
GIMP and save it out using the gimps 9 compression setting for a
png and I get a smaller file.  The gimp has a "indexed" setting for
png file.  I don't know what that is compared to RGB but all PIL
pngs open up in the gimp as RGB, not indexed.

My question is how do I create these smaller sized files with PIL.
There is supposed to be a optimization option for saving pngs
but I can't get it to work.  What is the complete synxtax for
saving an image with optimization?  Anyone have advice on
producing more compressed pngs with PIL?

Thanks

please reply to bryan@dunsinane.net