ISO

I ripped an ISO of a dvd I own to my hard drive using anydvd hd I then successfully burned it to a dual layer dvd using Power2Go. Everything went well and it plays back flawlessly. My question is this. Is the quality of the video less than the original using this method or is it an exact copy of the original. I can’t see any difference. P.S. It was burned with no compression. I’m interested in doing the same thing with blu ray but will not go thru the expense if there is a reduction in pic quality from the original.