Fractal inverse problem: The fractal inverse problem is an important research area with a great number of potential application fields. It constists in finding a fractal model or code that generates a given object. This concept has been introduced by Barnsley with the well known collage theorem [Bar88]. When the considered object is an image, we often speak about fractal image compression. A method has been proposed by Jacquin to solve this kind of inverse problem [Jac92].