Fractal block coding using a simplified finite-state algorithm

The exhaustive search process leads to a computational burden and therefore increases the complexity in the fractal image coding system. This is the main drawback to employ fractals for practical image compression applications. In this paper, an image compression scheme based on the fractal block coding and the simplified finite-state algorithm is proposed. For the finite-state algorithm that has been successfully employed in the vector quantization (VQ) technique, the state codebook (equivalent to the domain pool in the fractal image coding) is determined by a specific next-state function. In this research, we use the position of the range block to decide its domain pool. Therefore, a confined domain pool is limited in the neighboring region of the range block and thus the search process is simplified and faster. During the computer simulations, we consider two partition types, the single-level (8 X 8 blocks) and two-level (8 X 8 and 4 X 4 blocks) conditions. The simulation results show that the proposed scheme greatly reduces the computational complexity and improves the system performance.