About 15 years when I got my first digital camera, I noticed that there were always a few dots in the same spots that were bright white/red/green/blue no matter what the settings on the camera were or what the picture was of. I found out these were "hot pixels" and were caused by defects in the sensor. I'd always wondered if someone could create an algorithm to match photos to a specific camera based on hot pixels. It seems like this is exactly that.
Yeah, cameras calibrate out those pixels essentially by taking a photo of total darkness (taking an exposure while the shutter is closed) and discarding any pixels that still read bright. I noticed this happen a while back and the location of the dead pixel was visible if I took a photo of fabric. I could see where the pixel was being interpolated from surrounding pixels. Super subtle, I could only notice by knowing a-priori where the dead pixel was, but something that an algorithm could detect.
I wonder how well this fingerprinting technique works when photos are resized or manipulated, though.
For certain types of photography (for example low-light) it's important to remove them if you care about quality, I think software for getting rid of hot pixels came first. All you need is enough suitable shots from the same camera, so it's sort of trivial. Of course this can also be used as a sort of fingerprint, so it's true that if you want to share photos truly anonymously you need to get rid of those pixels in addition to the metadata.
Laser printers (color ones) are (were?) required to have some sort of built in imperfection because they were too good and could be used for counterfeiting.
I wouldn't be surprised if this eventually is a requirement for cameras, you know, just because law enforcement wants it.
I have a feeling that someone like Samy Kamkar is already thinking about writing a convenient tool to replace the fingerprint of one camera with that of another on a photo.
(Hm, the latest entry on samy.pl is two years old. Is he well?)
Well the Dutch are famous for their work ethic. Seriously, an assertion like that is easy to make but it could well be that they are better about keeping statistics and are more willing to publish them transparently.
Same issue with the numbers on sexual abuse in Sweden, they are more often reported and the definition is broader than the common sense belief. Numbers appear ridiculous (to the point where the alt-right loves taunting Swedes with "rape capital of the world" and such) but it's just a matter of much better statistical collection, and more nuanced (and broader) interpretation of what configures sexual abuse.
It would be far easier to force phone and camera manufacturers to “embed” a fingerprint in the photo than to measure every sensor.
Also these fingerprints in reality are very flaky and the higher the quality of the sensor the less of a fingerprint there is to work with.
The fingerprints are also dependent on specific operating conditions which can change with firmware and operating parameters (e.g. digital zoom / cropping) as well as environmental conditions such as light levels and even temperature.
The file, but not the image. Also easily removable, although companies have been clearly encouraged to make this difficult in mainstream software and to set maximal defaults. Probably doesn't take much encouragement, because the more metadata, the more automagic.
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I wonder how well this fingerprinting technique works when photos are resized or manipulated, though.
I wouldn't be surprised if this eventually is a requirement for cameras, you know, just because law enforcement wants it.
There's also a pattern of circles on currency that color copiers and Photoshop will read and then refuse to work on: https://en.wikipedia.org/wiki/EURion_constellation
(Hm, the latest entry on samy.pl is two years old. Is he well?)
How does a city of only 200,000 people earn this title?
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[0] https://www.dailymail.co.uk/sciencetech/article-5262297/Face...
Also these fingerprints in reality are very flaky and the higher the quality of the sensor the less of a fingerprint there is to work with.
The fingerprints are also dependent on specific operating conditions which can change with firmware and operating parameters (e.g. digital zoom / cropping) as well as environmental conditions such as light levels and even temperature.
edit https://packages.debian.org/search?keywords=exif