Anamorphosis is a distorted projection or perspective requiring the viewer to use special devices or occupy a specific vantage point to reconstitute the image. The word "anamorphosis" is derived from the Greek prefix ana-, meaning back or again, and the word morphe, meaning shape or form.
Read more about Anamorphosis: Types of Projection, History, "Anamorphic" Effects in The Work of Contemporary Artists, Impossible Objects, Popular Culture