[wubbert]

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.

[Manuel_D]

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.

[_trampeltier]

Thermal cameras does it all the time too. They have a shutter and calibrate each pixel when the camera gets warmer.

[trompetenaccoun]

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.

[dontcare007]

Seems like an opportunity for an anonymous service. Post calorie editing if photos to remove identifying fingerprints...

[noja]

You could do something similar with the lens too.