An anamorphosis art is a deformed image that appears in its true shape when viewed in certain perspective. In the early Renaissance period, European artists began to master perspective and became fascinated by the simplest kind of anamorphic art i.e. stretched pictures seen accurately when viewed at a sharp angle. For these artworks, the cylindrical mirror forms image from the continuous infinite image. 5 more pics after the jump.

Source: TechEBlog