Jack Parker, bless his heart, showed me the following link:

http://www.ianrowland.com/MiscPages/Mrangryandmrscalm.html

Be sure to move as far away from the sceen as possible before looking at the screen or squint your eyes. You will see an angry dude to the right and a neutral faced woman to the left. Move closer to the screen and they will switch places.

I made a few attempts:

http://www.7pixelssouth.com/tomas/HalloweenRealColor.jpg
http://www.7pixelssouth.com/tomas/RinaTomas.jpg
http://www.7pixelssouth.com/tomas/SoSad.jpg
http://www.7pixelssouth.com/tomas/Neutral.jpg
http://www.7pixelssouth.com/tomas/Marloyn.jpg
http://www.7pixelssouth.com/tomas/AbsolutPamela.jpg

Can be used in magic: Give someone on stage a pack of photos. They should be live size so maybe A4 size will be good. The spectator is hypnotized to only see sad people. He takes the top photo, imitates its expression and holds it up next to his head. The audience will see him make a sad face while the photo shows someone laughing hard. Let it be repeated. Then hypnotize him to see happy people. So half way through the photo packet the close-up faces start being happy instead.

/Tomas

Wow! This illusion is incredible! It is very, very interesting. I particularly like your Absolut picture. This is fascinating.

Very nice illusion. Can you explain me how can you do it with Photoshop, or where can I find online more info about it? PM me, thanks

Dave

The info I used to make the images I found at

http://cvcl.mit.edu/Papers/Schyns-Oliva99.pdf

/Tomas

An easy way to see the differnt images, for me anyway, is to remove my glasses!

I'm short sighted and without my glasses things blur and I get the alternate view.

Cool illusions.

Very nice!

I like your routine concept for using the illusion!

I actually use the original on a Powerpoint slide and change its size up and down when I give certain lectures!

All the best,

Bruce

Excellent!
Thomas what software did you utilise to segregate the frequencies? (hsf and lsf)
Thanks.

Wayman, I used Photoshop. The only two things the software needs to be able to do is blurring the image and making calculations (add and subtract) between images.

/Tomas

Ok, Thanks a lot thomas, I read the artical you linked, and I think I understand.
now where did I put my paint brushes.....