I have a need to extract an iso from a script as a non-root user.
The solution I found is to use good ole 7zip. From previous experience I knew it could open up iso files on Windows. They have a Linux version.
Here is the 7zip download page. I recommend downloading the binary verison for linux if you don't want to compile from source.
Here is some sample syntax to extract an iso:
7z x -oOutputDir LargeLinuxIso.iso
I mentioned Windows in the title because 7zip is cross platform and these instructions apply there as well.