Comment by gumby271
3 days ago
I'm sure Apple would love that too. More seriously, would that also mean all editing tools would need to re-sign a photo that was previously signed by the original sensor. How do we distinguish an edit that's misleading vs just changing levels? It's an interesting area for sure, but this inverse approach seems much trickier.
CAI’s Content Credential standard accommodates what you suggest, as far as re-signing/provenance, with a chain kind of approach. It supports embedding “ingredient thumbnails” in an image’s manifest, and/or the image’s manifest can embed or link back to source images that are in turn also signed [2].
It feels like the approach assumes a media environment where a professional wants to provably “show their work,” where authenticity adds value to a skeptical audience.
In that spirit, then, I understand CAI’s intention [0] to be to vest that judgment with the creator, and ultimately the viewer: if my purpose is to prove myself, I’d want to show enough links in the chain that the viewer checking my work can say “oh I see how A relates to B, to C,” and so on. If I don’t want to prove myself, well… then I won’t.
I don’t know Adobe’s implementation well enough to know how often they save a CC manifest, and their beta is vague in just referring to “editing history.” [1] I get the impression that they’re still dialing in the right level of detail to capture by default. Maybe even just “came from Firefly” and “Photoshop wuz here.”
But if I want to prove this Nikon Z9 recorded these pixels at this time and place, or “I am the BBC and yes I published this,” or “only the flying monkey was GenAI, the rest was real” I could conceivably put together a toolchain (independently of Adobe) to prove it in more detail.
[0] https://spec.c2pa.org/specifications/specifications/2.2/spec...
[1] https://opensource.contentauthenticity.org/docs/manifest/und...
[2] https://opensource.contentauthenticity.org/docs/c2patool/doc...
You'd have to provide both images, and let the end user determine whether they think it's misleading.