This is a somewhat usable "proof of concept" C program for decoding Aurora's .im file format. It can be used as is or it can (with some effort) be modified to be used as a "plug-in" for something else. The decoding is done in imdec.c with structures from imstructs.h
It requires libpng (im2png) or libSDL (imview). See the included readme.txt for more instructions.