Remember this general rule of thumb when selecting a "HIGH RESOLUTION" camera: If a camera manufacturer states "xxx by xxx pixels" as a "resolution", then put that camera down and run. Quality cameras don't play this game. They state real horizontal resolutions. If the Horizontal Resolution isn't either 420,480, or 540, steer clear. Lower quality and older CCD chips state resolutions in pixel dimensions. High quality CCD chip makers will either carry 480 or 540..anything less..or an odd number near this resolution would come from a lower end product.
Once upon a time, a camera manufacturer handed me their latest camera and said it was the highest resolution IP camera they had available. When I asked about resolution, they started giving me active pixel dimensions. It wasn't until I ran the camera through a waveform analyzer that they finally said, "you are keen to this" when told that 376 lines of resolution did not qualify as "high" in my book. Never have I seen a high quality camera that gives resolution specs solely in pixels.