Fixed points Fractals 8 Functional equation 8 Self-similarity 8 Approximation theory 4 Block codes 4 Block-coding 4 Digital signal processing 4 Dilation equation 4 Fractal compression 4 Grey-level functions 4 Image coding 4 Image reconstruction 4 Inverse problem for fractals 4 Mathematical operators 4 Refinement equation 4 Theorem proving 4 Wavelets 4 Dirichlet problem 2 Mean curvature 2