Approximate nearest neighbour search for fractal image compression based on a new affine transform parametrization

Since the birth of fractal image compression, there has been numerous research which aimed at speeding up the encoding step. One of the most innovative and promising approaches was by converting the range-domain block matching problem to a nearest neighbour search problem. However, the conventional approach suffers from two drawbacks: quantization errors of the affine transform parameters and the large memory requirement. This paper presents some enhancements to the approach based on a new affine transform parametrization. Experiments showed that our technique is able to improve the fidelity and significantly reduce memory requirement with similar encoding time and compression ratio