3 ms·
I was always fascinated by stuff like LSB stenography where you hide a message (or another image) in the least significant bits of an image. Not visible to the
by ZenMikey 2y ago
I was always fascinated by stuff like LSB stenography where you hide a message (or another image) in the least significant bits of an image. Not visible to the human eye, mathematically should look like thermal noise in the image at most.
- Retr0id 2y agoImage sensor noise is not a uniform distribution (I believe it's typically modeled as a Gaussian distribution, but even that's an approximation). Thus, it is mathematically/statistically distinguishable.
- NavinF 2y agoThe LSB of samples from a gaussian distribution is uniformly distributed: 50/50 chance of 0/1 (Assuming you have enough bits per sample which image sensors provide IRL)
- Retr0id 2y agoOnly in theory. In practice, they're correlated with the other bits and adjacent pixels.
- NavinF 2y agoHow correlated? I spent 2 minutes trying and failing to get chatGPT to generate code that downloads an image dataset and runs diehard on the LSBs. I'd expect the LSBs to pass the randomness test.