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Comment by coldcode | Hacker News Reader

I remember reading a paper on confusing road sign recognizers by adding certain bits of noise to the sign that completely baffled the recognizer. I wonder if one could do this to the license plate which would still look normal to a human but be unreadable to an AI.

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This sort of technology only works for a particular training of a particular neural net. Text recognition of a fixed font is easy enough that I'm sure there are several different competing readers. Defeating even one of them requires having access to its inference results. Defeating all of them simultaneously is almost certainly infeasible, even if you did have its inference results available.

Most plate cameras rely in part on the reflectiveness of the plate. You can definitely modify a plate to be mostly illegible to these cameras but easily human readable.

Given that most cameras are sensitive to IR (but human eyes are not), it seems like you could also wire up some super bright IR LEDs to obscure the plate too. Hmm... idea for a new license place 'holder'...

Wouldn't it be better to use IR to saturate the camera?

I think they use IR to 'light' up the plates at night, otherwise the exposure time would be too long to pickup a license plate.

Should make your car invisible to dashcams too.

I want an IR detector for my car, so I can know when I'm getting hit by one of these things. Not that it will accomplish much.

Yes, 'saturate' is the word I wanted to use. Basically, the light source(s) are pointed at the camera, and it is unable to make out anything near the light source(s) as a result.

Maybe some transparent non-IR reflective paint?

Which would result in getting instantly pulled over then?

It'd make a great political statement (or prank) in that case.

On what grounds?

Concealing your license plate or it not being easily visible. The same reason the darkened plate covers are often illegal and why putting it on the inside of your window is generally frowned upon.

It doesn't really matter if it is legal or not for them to do, I'm pretty sure they'll do it nevertheless. I had a cop pull me over for the light over my plate being out. The cop said he couldn't see my plates when he was right behind me... at night with his headlights turned off (He turned them off while driving behind me, turning them back on right before the lights started).

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