Copyright Re: Illustrating famous people?


Hi does anyone have any advice with regards to how copyright works if, say I wanted to design something from a photo of a famous artist and vectorise it in photoshop or illustrator so it's my own work, but unequivocally an image of this person, do you need permission from them?

What if they are dead?

The person I have in mind is now dead. It's for a creative invite and I need to know this before I go and do it, in case it can't be used anyway for copyright reasons. It is for display in a public place, where people have to pay to get in, ie. a private venue.
Don't forget that even if the subject of the photo is dead you might have problems with the photographer or owner of the rights to the photograph. I'd either do your research really well or try something else.
If you make it your own - redraw completely (and not do a forgery!) you should be OK I would think....