/sci/ - Science & Math

>>4229590
>>4229595
>>4232352
The dots are in fact from the Outguess steganography program. The reason it's in 8x8 blocks is because JPEG compresses each 8x8 block of an image separately, and since it's lossy compression, OutGuess has to modify the compressed data rather than working on individual pixels in the image.

Here's a solid color image with a test message hidden in it. You'll find the same artifacts.

It's actually good practice to use photographs instead of solid color images if you're hiding messages in them, because these kind of artifacts give the presence of steganography away.