Let's bump this with a necropost, for Slackware 15:

I couldn't find my printer, the MG5350 supported in SBo under either the pixma package or the cnijfilter2 package, but compiled and installed the pixma package anyway. I then set up the MG3500 and the MG5500 in CUPS hoping one of them would be compatible with my printer. But no luck, it didn't print.

From Canon's web site, I downloaded and converted cnijfilter-mg5300series-3.60-1.x86_64.rpm to a tgz. However, note that, at the end, I didn't install cnijfilter-common*rpm as it seemed to break the CUPS installation, causing me to reinstall it with slackpkg - missing on cnijfilter-common doesn't seem to matter anyway as the same executables are also in SBo's pixma package.

Still no luck. It turned out 3 of Canon's executable reported with ldd:
libpangox-1.0.so.0 not found
libtiff.so.3 not found
libpng12.so.0 not found

I took a big gamble with:
# ln /usr/lib64/libpango-1.0.so.0 /usr/lib64/libpangox-1.0.so.0
# ln /usr/lib64/libtiff.so.5 /usr/lib64/libtiff.so.3
# ln /usr/lib64/libpng14.so.14 /usr/lib64/libpng12.so.0
# ldconfig

and guess what, in spite of this dodgy linking, it now works!

Anyway, thought it might help someone somewhere as it took me many hours to solve this...