I have some older footage shot on tape in SD on a green screen. I'm not sure of the process of how the vendor got it from tape to digital, but they told me it was the highest quality footage they had. When I pull it into Ae, it's got alot of crawly artifacts on his suit and hair, as seen here: 
Actually the compression that adobe put on the image you can hardly see them in this image, but believe me they are there. What can you do with that? I've tried curves, to crush the blacks a little, and that helps, but is there a better solution?