A New Fast Fractal Coding Approach Based on Wavelet Decomposition
Qian Feng · 2003
In order to reduce image coding time,a new fast fractal method based on wavelet decomposition is presented in this paper. This algorithm is mainly implemented in two fold. Firstly, according to the feature of wavelet decomposition whose energy is ununiformity distribution in subbands of whole wavelet transform image, the low frequency region, where most of energy concentrates, is regarded as a kind of image, and can be encoded with traditional fractal method. Secondly, owing to the similarity of subband image among different channels after wavelet decomposition, instead of global search mechanism we have introduced a local optimal solution to gain the whole image's fractal parameter by suitable scale transform of low frequency region's. The analysis and results show that the encoding speed is improved greatly in case of the fixed compression ratio, and the quality of the reconstructed image can be better retained. It's very evidently that the dissymmetry between the encoding and decoding process has been reformed drastically.