Can you use Altered Art Cards/ Extended Art Cards in Magic the Gathering Tournaments?

I'm not talking about the textless wrath of god cards or any other card that is put out by Wizards. I bought a collection of cards and in there was a a couple 6th edition cards where they made the white borders black with a sharpie it looks like. They also extended the art of an Overgrow Tomb to the entire card using pastels. Could I take any of those cards to a Regional or Pro Tour Qualifier, or would they be considered "marked" cards?