C64 Graphic Converter v1.2 by Georg Schwarz (March 1991) - This handy graphics file converter will take as input, a standard bitmap, amica paint, blazing paddles, c128 graphics, doode, giga-cad+, giga-paint, giga-paint window, hi-eddi, koala painter, ocp art studio, paint magic, print fox, star painter and compressed files.  You can then output to C128 bitmap, doodle, giga-cad+, giga-paint, giga-paint window, hi-eddi, printfox, star painter cut, star painter 64, star painter 128 or compressed.  There are also some extra features that let you do things like invert a pitcure, mirror it (both horizontally and vertically), copy and so on.

Original source is here.