Derived from the Greek, anamorphosis means to transform and that is exactly what is achieved with this technique. The idea is to deform the lines of an image on a flat (or curved) surface so that they recover the natural aspect when viewed only from a specific point of view.
In short, anamorphism or anamorphosis consists in the creation of an optical illusion achieved through the study of form and perspective. To put it into practice you need a high knowledge of mathematics, proportion and drawing.
It is not a new technique, look at the skull on the floor of this painting by Hans Holbeinm, “The Ambassadors”, from the year 1,553. The skull, which represents vanity, appears deformed until we are at a certain point where the image is composed.
Currently, the best known cases of anamorphosis can be found in street paintings, here are some examples: