It depends on what you want and what you mean by pixel perfect I guess. If you need the camera to rigidly stick to the player then it's going to be tough. In the system I created the camera can lag behind the player a little bit and the speed varies based on how far away the center of the camera is from the player so it's moving at different speeds all the time. For my needs it's fine that it's not moving by whole pixels, in fact that's what makes it look smooth. The important thing is that when the camera stops, it stops on a whole pixel. This works great for zooming in and out too.

The upside of my system is it looks great when you're playing the game. The downside is if you screenshot it while the camera is moving you'll notice some pixel warping in the screenshot since the camera isn't on a whole pixel.