Generalized Cloaking and Optical Polyjuice

In this paper, a generalization of cloaking is presented: instead of an empty region of space, an inhomogeneous structure is transformed via Pendry's map in order to give, to any object hidden in the central hole of the cloak, a completely arbitrary appearance. In 2006, it was suggested by Pendry et al. [1] that an object surrounded by a coating consisting of an exotic material becomes invisible to electromagnetic waves. This device was named " invisibility cloak " in reference to Harry Potter, the popular character of J.K. Rowling. Beside his famous cloak, the little wizard has other spells to go unnoticed. Among the most spectacular is the " polyjuice potion " that is able to turn somebody into anybody else's appearance [2]. In this paper, we do not present