That was cool. We used to do that kinda thing in art class.
I was suprised when i saw it, thats why its here:-) Pretty werid though, i never seen anything that worked liked that did. If anyone has, send link, i like to see it! 
Is there perhaps some kind of paint-programm that allows you to convert normal pics in pics like that?
I also was surprised, since I even forgot the title of your post 
you know what, i think so, But it makes it black and white(you can change the contrast), but the hard part is, how do you get the picture to show up in your head?
I like these sorts of optical illusions. There is a medical explaination for this that I’ve heard, too bad I don’t remember it. 
I have also seen the American Flag used in this trick. While I searched for it on the web I found some more very interesting eye tricks. But here is the flag:
https://pictures.funnyjunk.com/pages/flag.gif
I found it on this site at the bottom of the page:
https://www.funnyjunk.com/pages/optical_illusions.htm
I also came across this site on my search for the flag:
https://homepage.ntlworld.com/con1_uk/FunStuff.htm
Scroll through the bad math trick that’s at the top to get to the good stuff.
My favorite from that page is this one:
https://64.246.20.141/~admin3/admin2/images/crazyillusion.jpg
Wow! 
The 2nd and 3rd pictures of spirals are pretty perplexing also! :oof: 
This last page has a few images that don’t load.
That was the coolest thing I’ve ever seen.
Its not that amazing, its just after image, and after images are negative, why this picture is negative. I found one which i personally think is better:
https://handyhub.cjb.net/queen.zip
That one didn’t seem to work for me. The rest of them had somewhere to stare at. Where do you look at this one?
The black dot on right, around where her ear should be.
Jesus and Queen worked for me, too much staring so I skipped the flag. And anyway I don’t want to see the US flag when I close my eyes hehe…
Freaky because the queens face disappeared after a second… crazy shit.
I saw a dude with a mustache. Is that what it should have looked like?
LoL…‘That dude with a moustache’ was Queen Elizabeth.
These type of piccie…the negative after-image ones are easy to make with any type of paint program…just change the image to 2 colours and then negative image it.
The image may need to be tweaked a bit to get the intensity but it is simple to do.
My favourite image from the lot posted in this thred is the elephant one with many feet. 
Pretty Good Links, some were pretty cool, that other link from the first site was some old school stuff that i rememeber from High School. That jesus one was the most unique one, but they all seem to be orginal. If see anymore please link them 
It looked like queen Elizebeth in the piture, but the after image looked like a guy with a mustache.
I made one of myself with an old pic, seems to work but I can’t fill my face with details, looks terrible 
Wow…that was a pretty good effort chosenone. I’ll have to do my own now…hehee. You’re cool! . . . . . . . . . Here 'tis! Negative Piccie of ME!!
Yeah yours is pretty cool, but we both have the same problem - since we have no black in the middle of our faces discluding the nose lips and eyes our faces look too 2-dimensional…
https://mr-31238.mr.valuehost.co.uk/assets/Flash/psychic.swf
Here’s a new site, that was pretty cool, it reads your mind!
Send cool sites like the Jesus one or the psychic site, i like those type of things
Yeah I saw that psychic thing a day ago - it freaked me out 
yeah, i was trying to figure out if it was all like a math trick or something, but then i started to think…how the hell do they know what #'s im adding??? This thing is very cool yet freaky, i agree :oof: