Anamorphic illusions are images that require the viewer to see them from a certain vantage point in order for the image to not appear distorted. These illusions exploit the fact that our brain interprets reality based on spatial and geometrical cues. Some anamorphic images have elements that appear to be the same size when this is not the case. A common example of this type of images is the text of road markings which employ an anamorphic design because the driver views them from a very acute angle when approaching them.
A striking historical example of anamorphic images are the photos of soldiers forming patriotic symbols that photographers Arthur Mole and John Thomas took during world war I as part of a campaign to sell war bonds. In the photo below, 18,000 soldiers were assembled to form an image of the statue of liberty. The anamorphic character of the image is evidenced in the fact that 12,000 of those 18,000 men were required just to form the flame part of the stature’s image.
Using the right spatial and geometrical cues, two-dimensional images can be made to look three-dimensional as long as they are viewed from a specific vantage point. In the video below, the folks from the You Tube channel bursspup construct an amazing anamorphic illusion using lit candles.
The image of the human statue of liberty by Mole and Thomas is in the public domain.