Trigger Olympus SP-600UZ Camera shutter via USB port from Arduino Nano


I can purchase an electronic remote shutter trigger for my Olympus SP-600UZ digital camera which the vendors claim will work through the USB port.
However I would like to trigger the shutter from my Arduino Nano (using the camera USB port of course) for panoramas and time lapse images.
Has anyone got some ideas on how to do that and what the protocol might be? Any thoughts would be appreciated.