I just received this illusion via email and thought everyone would enjoy it here.

If you watch the images from your seat in front of the computer, Mr. Angry is on the left, and Mrs. Calm is on the right.

Get up from your seat, and move back 12 feet, and PRESTO!! they switch places!!

According to the email, this illusion was created by Dr. Philippe G. Schyns and Dr. Aude Oliva of the Univ. of Glasgow.

I've never seen this one before.... that's a weird one!

What an excellently crafted illusion! :nod:

Hope I'm not going to spoil this (too much) by explaining how it works - actually there are a few useful lessons here for all of us. ;)

1) When you are viewing close up, the details are easy to make out. The first attachment below has a High-pass filter which show the effect of observing the details;

2) At a distance we no longer see details, just the general format. The second attachment has a Gaussian Blur to mimmick this effect. Another thing to consider is that when we are at a distance the image will appear smaller, so the effect of the Gaussian blur gets offset somewhat - the image will "appear" to be sharper this way.

Some lessons......
a) Don't always look at your work at the same "distance", zoom in and out to check. This illusions proves very dramatically that unexpected things can occur!

b) A smaller version of an image will always look sharper than a larger version of the same.

c) We never just see images, we will always try to interpret them - which is the base for almost all optical illusions. Some tricks however can be used to our advantage. For example, to "sharpen" and image you can add some overall noise or, better still, introduce a paper texture. Try it!

Thank you makeovermagic. Got any more?

Rô

Courtesy of Aude Oliva (Massachusetts Institute of Technology, Cambridge, USA) and Philippe G. Schyns (University of Glasgow, Glasgo,w UK)

On a close-up view, you can see on the left face, an angry man and on the right face, a woman with a neutral facial emotion. But further back, the faces change expression and even genders! if you squint, blink, or defocus, an angry man should substitute for the face of the woman and the left angry face should not be angry anymore.

This impressive illusion created by Dr. Aude Oliva and Dr. Philippe G. Schyns, illustrates the ability of the visual system to separate information coming from different spatial frequency channels. In the right image, high Spatial Frequencies (HSF) represent a woman with a neutral facial expression, mixed with the low spatial frequency (LSF) information from the face of an angry man. On the left, the face of the angry man is represented in fine details whereas the underlying female face is made of blur only ("blobs")

The above two ambiguous faces, termed hybrid faces, are published in the journal Cognition, 69, 243-265, 1999. Elsever publisher

from site: http://cvcl.mit.edu/gallery.htm

here's another example; female to male -- stand back to see the difference.

M.O.M.

p.s. i don't know if there is a copyright violation by posting this here; i hope not.

byRo: thanks for your explanation. it is really fascinating, isn't it?

M.O.M.

Here's one that you should start viewing from farther back, then check it out from closer perspective.

Steve