Abstract
This paper proposes a novel algorithm to accelerate the encoding procedure of fractal image compression. We develop an indexing technology to access candidate domain blocks. The location of maximal gradient is adopted as the key for indexing. Only those blocks whose positions of maximal gradients matching that of a given range block are tested. In our experiments, the new algorithm promises good performance. It takes few seconds to encode a 512 by 512 image on a Pentium II 450 PC with a slight loss of decoded image fidelity.