Image Compression based on Iteration-Free Fractal and using Fuzzy Clustering on DCT Coefficients

In the proposed method, the encoding time is reduced by combining iteration-free fractal compression technique with fuzzy c-means clustering approach to classify the domain blocks. In iteration-free fractal image compression, the mean image is considered as domain pool for range-domain mapping that reduces the number of fractal matching. Discrete cosine transform (DCT) coefficient is used as a new metric for range and domain blocks comparison. Also fuzzy clustering approach reduces the search space to only a subset of domain pool. Based on Fuzzy clustering on DCT space, the domain pool is grouped into three clusters and the search is made in any one of the three clusters. The proposed method has been tested for various standard images and found that the encoding time is reduced about 42 times than the iteration-free fractal coding method with only a slight degradation in the quality of images.