Image smoothing?? Is it possible?

I'm making a little utility and one of the features is a zoom of a picture. Now this zoom is like a zoom window. To do this i am StretchBlt-ing from one picturebox into another. This is fine, but doing so makes the picture come out with mega jaggies. is there a quick way (cos its all being done as the user moves the mouse over the original picture) of filtering the picture? a quick look around shows a lot of huge loops but this is not what i need.

Anything anyone can mention to do this quicker?

Imge filtering algorithms are usually complicated and take a lot of time. The things with many loops you've seen could actually be simple algorithms.

thanks for the heads up.