Anamorphosis

István Orosz Anamorphic Column with Mirror

Hans Holbein's The Ambassadors

to see the anamorphic skull embedded in this painting click on it to enlarge it and then view the image from an extreme low angle from the left corner

This type of painting know as Anamorphosis (from the Greek "Formed Again") comes from a long tradition going back to the early Renaissance (15th Century) and even earlier, since the technique was actually invented in China before migrating to Italy. There are many famous examples, from Leonardo to Hans Holbein the Younger, from Andrea Pozzo to Marcel Duchamp and Salvador Dali, on to some of the street painters shown in the previous and this post.

This technique is also widely used in film to record a compressed image in a small frame (35mm for example) and expand

Here are some examples by Kurt Wenner and Julian Beever, contemporary masters of street art.

Kurt Weener's Ghetto

Kurt Weener's Office Stress

Julian Beever's Waterfall