Image Resolution

Really frustrating!  Okay, I import a bitmap image from a PDF into a Corel Draw file.   It looks crappy, pixelated and just not usable.  BUT, when I open the same image in Corel Photo Paint it looks perfect.  I've tried just about everything as far as changing the size, the resolution and anything else I can think of, but once I save it and return to Corel Draw, the image looks the same as before.  How can something look pixelated in Draw but perfect in Paint?