3 ms·

Not directly related but, I was at a security related convention and overheard some people talking about an image that when occupying <3/4 of a frame will crash

Not directly related but, I was at a security related convention and overheard some people talking about an image that when occupying <3/4 of a frame will crash any digital camera. (Phone, DSLR, IP Camera) Does anyone know anymore information about this image and effect? I imagine it's a bug in some low level firmware of a common IC for digital photography DSP but, I'm very unfamiliar with digital cameras. It also could have been complete bunk because I've not heard of it since and it wasn't being showcased at the convention.

jkot 12y ago
Flying RPG? Now seriously, modern cameras have face recognition and ton of other features. It should be possible to cause crash.
Houshalter 12y ago
Could be related to this? http://en.wikipedia.org/wiki/EURion_constellation http://en.wikipedia.org/wiki/EURion_constellation
- TazeTSchnitzel 12y ago
  It's most likely not the constellation itself, but the other mechanism: https://en.wikipedia.org/wiki/EURion_constellation#Other_banknote_detection_mechanisms https://en.wikipedia.org/wiki/EURion_constellation#Other_ban... In particular, have a look at this: http://www.cl.cam.ac.uk/~sjm217/projects/currency/ http://www.cl.cam.ac.uk/~sjm217/projects/currency/
deleted 12y ago
[deleted]
geographomics 12y ago
Not what you're looking for, but your comment reminded me of this: https://en.wikipedia.org/wiki/BLIT_%28short_story%29 https://en.wikipedia.org/wiki/BLIT_%28short_story%29
userbinator 12y ago
If there is such a thing I'm more inclined to believe that it's an analogue effect, rather than a bug in software/firmware. it's similar to the effect that causes some monitors to emit audible sound when displaying certain images: https://news.ycombinator.com/item?id=8862689 https://news.ycombinator.com/item?id=8862689 Digital camera sensors output a stream of bits that depend on the intensity of the light reaching the pixels. For normal images, there is (relatively speaking) not so much contrast, so the signal has few high-frequency or repetitive components to it. However, if you point the sensor at an image that effectively causes each pixel to be alternating from full dark to full bright, the signal becomes far more regular and the high-frequency components increase significantly. A possible problem is that, since the bulk of the power draw occurs when a bit transitions from 0-1/1-0, this repetitive and high-frequency signal causes more stress on the power supply circuitry (look up "voltage regulator oscillation"), and if it causes voltages to go out of tolerance, can crash the system. I suppose an image that produced a stream of 010101010... for each pixel's value could also be an example of this. Other resonant effects may also play a role in this; if the oscillation frequency happens to synchronise with something else, physical damage is a possibility if the components are pushed beyond absolute maximum ratings. It's an extreme edge case, not normally encountered in use. The reason why I think this could be plausible is that, although I've never tried/experienced this with a digital camera, I had an old analogue video camera that would work fine in all circumstances except when pointed at a monitor displaying its image, upon which it would emit a loud high-pitched whine and then shut itself off. I discovered that one of the power supply rails would go into oscillation when the camera saw itslf, and this was enough to shutdown the system. Adding some extra supply decoupling was enough to stop this from happening, but apparently this problem has been known for a while: http://en.wikipedia.org/wiki/Video_feedback http://en.wikipedia.org/wiki/Video_feedback

jkot 12y ago

Flying RPG? Now seriously, modern cameras have face recognition and ton of other features. It should be possible to cause crash.

Houshalter 12y ago

Could be related to this? http://en.wikipedia.org/wiki/EURion_constellation http://en.wikipedia.org/wiki/EURion_constellation

TazeTSchnitzel 12y ago
It's most likely not the constellation itself, but the other mechanism: https://en.wikipedia.org/wiki/EURion_constellation#Other_banknote_detection_mechanisms https://en.wikipedia.org/wiki/EURion_constellation#Other_ban... In particular, have a look at this: http://www.cl.cam.ac.uk/~sjm217/projects/currency/ http://www.cl.cam.ac.uk/~sjm217/projects/currency/

deleted 12y ago

[deleted]

geographomics 12y ago

Not what you're looking for, but your comment reminded me of this: https://en.wikipedia.org/wiki/BLIT_%28short_story%29 https://en.wikipedia.org/wiki/BLIT_%28short_story%29

userbinator 12y ago

If there is such a thing I'm more inclined to believe that it's an analogue effect, rather than a bug in software/firmware. it's similar to the effect that causes some monitors to emit audible sound when displaying certain images: https://news.ycombinator.com/item?id=8862689 https://news.ycombinator.com/item?id=8862689 Digital camera sensors output a stream of bits that depend on the intensity of the light reaching the pixels. For normal images, there is (relatively speaking) not so much contrast, so the signal has few high-frequency or repetitive components to it. However, if you point the sensor at an image that effectively causes each pixel to be alternating from full dark to full bright, the signal becomes far more regular and the high-frequency components increase significantly. A possible problem is that, since the bulk of the power draw occurs when a bit transitions from 0-1/1-0, this repetitive and high-frequency signal causes more stress on the power supply circuitry (look up "voltage regulator oscillation"), and if it causes voltages to go out of tolerance, can crash the system. I suppose an image that produced a stream of 010101010... for each pixel's value could also be an example of this. Other resonant effects may also play a role in this; if the oscillation frequency happens to synchronise with something else, physical damage is a possibility if the components are pushed beyond absolute maximum ratings. It's an extreme edge case, not normally encountered in use. The reason why I think this could be plausible is that, although I've never tried/experienced this with a digital camera, I had an old analogue video camera that would work fine in all circumstances except when pointed at a monitor displaying its image, upon which it would emit a loud high-pitched whine and then shut itself off. I discovered that one of the power supply rails would go into oscillation when the camera saw itslf, and this was enough to shutdown the system. Adding some extra supply decoupling was enough to stop this from happening, but apparently this problem has been known for a while: http://en.wikipedia.org/wiki/Video_feedback http://en.wikipedia.org/wiki/Video_feedback