I was offered a couple of DVDs from abroad that cannot be played on my player due to region filtering.
So I tried
k9copy to copy the DVD (it removes the region automatically).
But for some reasons the copy does not work well (followed the instructions from here but the generated ISO file does not work / not even in media player - additionally there are many bugs in k9copy 2.3.5 (latest from Ubuntu) showing that it is not a reliable software, at least not on Gnome...).
My question is simple: how to copy a DVD on Ubuntu, the copy/ISO being as close to the original, but without the region code.