Autostereograms | What is it ?
They are basically 3D images hidden within another image . They were quite popular in the 1990s , some 15 years after they were invented by Tyler and Clark .
Autostereograms | How do you see the hidden image ?
Its an optical illusion and in order to see the image , allow the eyes to “unfocus” and focus beyond the image , or behind the image . Some patience and training is required
Can you see the astronaut and the space shuttle in the image below ?
Below is a repetitive pattern . Can you see a sense of depth in the image ? Certain portion seems to be “floating” .
To find more of these images , you can google “autostereograms” . Alternatively , you can check out this [site here]
Autostereograms | Create your own
You can even create your very own autostereograms . Below is an image that I have created . There is a hidden 3D airplane in the image . To create your autostereogram , go to the website [here]
Now , how about a video with secret 3D images ? See the video below
Autostereograms | Why this happen ?
Humans and many animals have binocular vision . This is made possible if we have 2 eyes in front , not at the sides , like those of a chameleon . The physical position of these 2 eyes are different , and being infront , it creates views that overlap . This overlapping views gives us a sense of depth . Under normal conditions , our eyes helps us to keep in focus , but if we attempt to keep our eyes “defocus” , we create a stereogram .
Tyler and Clark created this single-image random dots stereograms , or autostereograms for short . To see the “hidden” image without the use of any equipment , the eyes need to achieve “free” fusion (defocussing) .
The key is to have regular patterns being repeated , but at a different distance . In the image below , the dots are closest together , followed by the crosses and the farthest being the fleurs-de-lis . Click on the image to see a bigger image and one will realise that the dots “floats” above and the fleurs-de-lis is positioned deep further down .
To get to know more about this , read here