Weighted fractal image coding

To encode an image by fractal image coding, it needs to find the best matched domain block for each range block. The best matched criteria is the difference measure between the range block and the domain block transformed by affine transform. This paper proposes a new method of fractal image coding, called weighted fractal image coding. To enhance the visual quality of the decoded image, the edge regions of the image are encoded with high weighting. The contrast scaling factor and the luminance offset factor in the affine transform are derived by minimizing the weighted difference measure. Experimental results show that the proposed method improves the visual quality of the decoded images in terms of weighted peak signal-to-noise ratio.