Comment by michaelt
18 hours ago
People have constructed video walls so high resolution they can film TV series in front of them and to an audience it's indistinguishable from a real set. It's extremely cost-effective for things like space fantasy that needs lots of exotic-looking backdrops, apparently.
It may not be in reach for you and I - but within reach of anyone with the budget to run a 'bot farm'
The high resolution video wall is quite simple. The hard part and why this has not been done earlier is that for filming, they had to synchronize the rendered background with the movement of the camera.
Movement is solved by tracking the camera's position and projecting the background from there.
Proof of captured image with hardware-based-attestation can be increased by adding extra information besides the RGB channels, like depth mapping (which a projected screen wouldn't be able to fake), and eventually light field recording (plenoptic imaging, e.g. Lytro).
also no, even in the high rez video walls its still possible to tell. maybe to an "audience" no but there are lots of fundamental flaws with video walls that make them not the same as filming it for real. all of those flaws show up in the final image and could be detected.
things like color rendering, sharpness, screen door/morie, motion blur, and yup even good ole depth queues in the lens system all show up as artifacts.
case in point, outside of a few specific niche cases like the mandalorian, that virtual production video wall thing is not actually being used all that much because of the amount of post shoot cleanup required to fix all those issues, it wasnt actually that much cheaper and its not really better either. especially when you factor in how hard it is to shoot that way.
> things like color rendering, sharpness, screen door/morie, motion blur, and yup even good ole depth queues in the lens system all show up as artifacts.
Pre-AI fake videos sidestep this sort of issue by lowering the video quality.
Add some motion blur, some camera shake, some poor lighting, the camera being slightly out of focus, and make the video 720p instead of 4k.
If they’re spending millions on faking an image, okay fine. That’s clearly not the security model intended for this feature though.
How large and pixel dense does a display need to be for it to convincingly fill an image sensor?
I suspect it’s significantly less than millions.