If your host is using CPanel, it is very simple. Just contact the provider and ask them to install the rpm NETPBM and this can be done easily under CPanel. Once it is installed, set the path to /usr/bin/ and you're all set to go!

Click on "Check Conf/Env" if you're using MyAlbumP and see if NetPBM is detected properly.

Lastly i recommend NetPBM for its ease of installation as well as sharp pictures. I have not used ImageMagik so i cannot comment on that.

Hope this helps!