The use of image smoothness estimates in speeding up fractal image compression

The paper presents a new attempt to speed up fractal image encoding. The range blocks and corresponding domain blocks are categorized depending on their smoothness parameter values (smoothness estimates), introduced, from the first, to characterize manifestation of high frequency components in the image. The searching of the best matched domain block is carried out between the neighbouring (or, within the same) smoothness classes. The computational complexity of the fractal image encoding process is reduced considerably. Theoretical and experimental investigations show that extremely high compression time savings are achieved for images of size 512x512.