First you have to determine where the noise or interference is entering the system. Is it being picked up by the camera? Or is the noise being picked up by the cable between the camera and the monitor or recorder?
The easiest test is to move a monitor very close to the camera using only a short cable to connect them. If the interference is gone or at least minimal, then it is likely that the cable is acting like an antenna and picking up the local radio station. In this case, you will need to use a cable with a better shield or enclose the cable in a shielded conduit. If neither of these work, you may have to modulate the video and send it down the cable as rf, rather than baseband video.
If the interference seems to be coming from the camera, then you have to either build an rf cage around the camera, or get a better shielded camera. Try wrapping the camera body in aluminum foil then grounding the foil. If this reduces the interference, then you need better shielding at the camera.
I think the solution is to reduce the interference before it corrupts the video. Once the signal is corrupted, it is very often difficult to filter out.