Jose Romanillos, managing director of Romanillos and Cook Image Rights Ltd, was among image rights specialists who said there were still plenty of reasons to join Guernsey's register, even though Rihanna was successful in UK courts without being signed up.
Image rights experts also warned there were very specific facts in the Rihanna and Topshop case which could not be relied on by other personalities.
Rihanna, pictured, most recently saw the Court of Appeal in London uphold a ban on the store selling a sleeveless T-shirt featuring a photograph of her without obtaining her permission.
The pop star sued Topshop's parent company Arcadia for $5m (£3.3m) in 2013 over the T-shirts, which featured a picture taken during a video shoot in 2011.
Mr Romanillos said not only were there specific reasons for Rihanna's success in her legal battle, the long-running action could have been avoided with image rights being registered.
'Our view is that if someone like Rihanna had image rights registered, all this would have been unnecessary and could have been avoided,' he said.
