Invisible Barcodes

The Japanese are crazy for barcodes, and not just in shops – there’s a real market for user-created codes that can be scanned by mobile phones with suitable software, and the trend looks set to move westward. Of course, being one step ahead the Japanese are already looking at the stealth-deployment options, despite a lack of obvious commercial purpose – Fujitsu have invented a way to invisibly conceal barcodes in printed pictures and graphics. So how do you know you’re supposed to scan it?