Weird Image

Hello, why are there weird looking images like this one on Sup Forums? What do these even mean?

Aliens

...

maybe there's something embedded in it but it's REALLY unlikely it's something you want

I wouldnt keep it on your computer because if it did contain illegal 0s and 1s you can be blamed even if you "didnt know"

is it some kind of virus codes?

well for example what are some of the bad things it could be?

you can't be cautious enough imo.
but in this case it may be just a fuckup of Sup Forums dealing with JFIF, which is the file format according to the header.

captain planet

Why does the thumbnail look so different from the actual image despite being the same size?

looks like your regular corrupted image. i've had images that turned partially green due to corruption.

Rotational velocidensity level of hard disk drive, right?

No it's literally a virus, the green color is the remain of organic activity. Unfortunately it also makes files more vulnerable to newer viruses.

Corruption in the jpeg; it tries to restart at the next macroblock, but the predictions are a bit off.

You can avoid this if you use the -restart option to cjpeg when encoding; that way only the part with the error looks messed up, but no one does that because it increases the size.

looks like we've got ourselves a computer expert. what is the source of your knowledge?

Actually reading the docs.

are gmask threads still a thing?

100% this.

kys brainlet

It's just glitch "art".

>doesn't know jpeg encoding
how does it feel to be dumb?

No it isn't, click on it. When the thumbnailer runs, it generates a fuckton of high frequency noise that actually looks like the image you see in the thumbnail. But when your browser decodes it, it only sees numbers in the top left of each 8x8 quantization square, and it looks completely different. Pic related

Just some fuckery that happens when you mess withe the luma and chroma QTs, I did generate an image like this a while back and Sup Forums did the same thing to it. Let me see if I can find it.
I wonder if the thumbnailer uses its own DQTs instead of reading them from the image.