Comment by pveierland
6 hours ago
Claim 7 in this patent application describes how depth sensors are used as part of an image authentication process, which would make such a workaround more difficult:
https://image-ppubs.uspto.gov/dirsearch-public/print/downloa...
The Apple Reference Image feature is here launched on iPhone 18 Pro and iPhone 18 Pro Max that both have built-in LiDAR sensors that could be used for this process.
Apple's current implementation doesn't integrate LiDAR. And LiDAR wouldn't be enough here, it's trivial to block the projector and hide the dot pattern. No dot pattern = iPhone thinks the object is far away, which is what happens in landscape photos.
A better fix is to take photos with all three iPhone cameras simultaneously, ideally as a 2-3s video, and use the parallax/multiple perspectives to extract depth information. The video files (Possibly audio too) could also be included with the verified image as additional verification.
They can also prevent photos if iPhone detects the LiDAR sensor is covered, similar to how Meta does it with their camera glasses.
> all three iPhone cameras simultaneously, ideally as a 2-3s video, and use the parallax/multiple perspectives to extract depth information.
I think optics could be used to make each camera see a different image.
A video could show shake, which could be verified against readings from the phone's accelerometer -- but you could just hold it still and claim that it was on a tripod.
> it's trivial to block the projector and hide the dot pattern. No dot pattern = iPhone thinks the object is far away, which is what happens in landscape photos.
I've never looked at the LiDAR hardware, but where is the emitter in relation to the receiver. Why would the LiDAR not reflect off of whatever you're blocking it with and return a very short flight meaning it was very close?
Paint the stopper vantablack then.
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I don't think it's an either or - additional data signals that need to correlate to authenticate will increase confidence. You can use multiple other signals to evaluate whether something is truly a landscape photo, and in that case not require a LiDAR capture, but if you are inside and at close range then you could assume that it should be part of scoring the authentication.
Similarly, LiDAR alone will help disqualify cases where someone is just taking a picture of e.g. a landscape target of the Golden Gate, but that it shown on a screen 1 meter away.
Right but I’d argue that realistically this feature is going to be most useful when taking photos of things reasonably close by, people especially, rather than landscape photography.
This approach makes me wonder if the future is actually going to move towards visual cryptography.
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iPhone lidar only works up to like 16 feet in the easiest lighting conditions (indoors) and may be functionally ineffective outdoors.
Still, that means that either the fake target scene and your screen presenting it would need to be outside of LiDAR sensor bounds, or you'd need to find a way to make the depth sensor data conform with your fake scene, both increasing the difficulty of producing a forgery.
https://news.ycombinator.com/item?id=49721878
> increasing the difficulty of producing a forgery
The problem with this thinking is twofold:
1) Whether it actually meaningfully increases the difficulty of a forgery remains to be seen. Despite their initial language about discerning real events, we see no details here about what scene information is used.
2) It increases the potential value of a forgery because now your forgery is attested by Apple.
So it either makes it easier to defraud people or more worthwhile to put in the effort to defraud people or both. None of those outcomes are great.
So you need a big enough screen to cover the entire field of view at 16 ft? Sounds expensive
Or, probably just some optics, like a slanted $9 IR mirror [1] in front of it, to direct the lidar to the sky/absorption box. Then you can point at the high res HDR TV that's probably already in your living room.
[1] https://commonlands.com/products/ir-cut-filters-csp650?srslt...
Well, first, that's only expensive if you're poor. The world is absolutely full of people who can easily piss away your entire annual income throwing a house party.
But I really mean that if the lidar barely works outdoors anyway then actually you don't need to be 16 feet away at all.
Anyway, one may presume that they've thought about this.
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furthermore, couldnt you do parallax from the multiple cameras as well as flicker the flash?
seems pretty easy to make it sufficiently difficult to trick the system