Anamorphosis is a very funny type of projection, that requires the viewer to use a special device or be placed in a particular position to be able to understand the image. Some artists have done some exceptional art works on pavements using this projection, check out the works by Julian Beever and Edgar Mueller. More information on anamorphosis can be found in Wikipedia where you can also find some more pointers to artist working with this projection.
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Drawing a large area of a city from memory after a 45 minute helicopter ride seems an impossible task. Yet Stephen Wiltshire, aka the Living Camera, did it in Rome with incredible detail. This is not his first 3 meter wide panorama. Starting with Tokyo in 2005, he has drawn Rome, Hong Kong, Frankfurt, Madrid, Dubai, Jerusalem, London and New York on giant canvasses. His most recent trips took him to Sydney and Shanghai in 2010.