A Study on Fractal Based Image Compression in Modified HSI Space for Various Geometrical Topologies

A study on fractal geometry based image compression has been carried out in Red-Green-Blue (RGB), Hue Saturation Intensity (HIS) and modified HSI colour space and a comparative study has been carried out on Lena and Pine images. The modified HSI scheme incorporates the concept of non linearity in the saturation of the colour in the image. The nonlinear model of HSI scheme is more realistic approach than the traditional HSI colour space. The output results have been obtained in the form of compressed image. In modified non-linear model, the processing speed and Peak Signal to Noise Ratio (PSNR) have been found to yield greater value compared to the other method but compression ratio has been obtained with lower values. The non-linear saturation, despite being a more realistic phenomenon, the self-similarity in the image may be lower and this may be considered as the major reason for lower compression ratio and higher processing speed.