A new affine transformation: its theory and application to image coding
The fractal image coding technique has attracted a degree of interest for its low bit rate. But the reconstructed image is of medium quality. This problem has prevented the fractal technique from being used practically. In order to improve the compression fidelity, a new affine transformation is proposed. Meanwhile, its contractivity requirement is analyzed, and the optimal parameters are derived using the least square method. The new affine transformation has been practically used in image coding. Experiments show that the PSNR can reach 28.7 dB at a compression ratio (CR) of 16.4 for the 256/spl times/256/spl times/8 "Lena" image. Comparison with other fractal coding schemes shows that the new affine transformation can improve the reconstructed image quality efficiently.