you'd need a display that has a couple bits more colour depth than the image sensor in question, and as far as I understand those displays don't exist. High-end Camera sensors now offer 12, 14 or even 16 bits per channel, that is way more than you can expect from any display technology we have, or likely will get, because (other than this application of spoofing image signatures) this kind of technology would be useless and expensive.
That said, the technology would only be credible if the audit trail of CA-signed signatures extends right to the sensor chip, and furthermore is of course Free and open-source.