EFI, Fujifilm, Konica Minolta, Ricoh and Xerox were among the companies targeted by Digitech, which also went after camera giants Hasselblad and Leica in its patent infringement suit.

The suit was originally filed in August 2012 in a California federal court, which invalidated the patent and entered judgement in favour of the defendants in August 2013. Digitech then appealed to the Federal Circuit Court of Appeals, which upheld the district court's decision last Friday (11 July).

Digitech's US Patent No 6,128,415 (the '415 patent) was originally filed by Polaroid in 1996 and effectively tries to patent the generation and use of an "improved device profile" that describes spatial and colour properties of a device within a digital image processing system.

Paul Sherfield of the Missing Horse Consultancy said the apparent attempt to patent the work of the International Color Consortium (ICC) was "unethical to say the least" and added: "I am pleased they appear to have failed".

The district court found that the "device profile" the '415 patent sought to protect was "nothing more than information" and therefore ineligible for patenting. It further described the patent as "so abstract and sweeping" as to cover any and all uses of a device profile.

EFI general counsel Bryan Ko said: "The Federal Circuit's decision confirms what we have maintained from the outset: that the patent is invalid and that EFI and its partners should not have been sued in the first place.

"We will continue to fight these kinds of meritless lawsuits in as many courts as is necessary to protect ourselves, our partners and our customers. As we have said before, we will not be bullied into settling abusive lawsuits by patent trolls."