A Study On Fractal Image Compression Based On Wavelet Transform

Image is some important kind of information carrier in our life and one image usually contains more abundant information than other medias, such as words. But the raw digital images are very big in size. If the image data couldn't be compressed efficiently, it will not meet the needs of high speed transmission and efficient storage nowadays. So, image compression, as a crucial, promising and vigorous technology in the fields of communication and multimedia, is rapidly expanding now.With the development of many new theories and new methods,a great deal of new image compression methods have been proposed in recent years. Wavelet transform and fractal image coding are the two important methods of them. Wavelet transform has the characteristic of multi-resolution, which fits to the human visual features; and fractal means the similarity in different scales of an image. Thus there will be great benefits to fusion wavelet analysis to the research of fractals. Various improved fractal coding algorithms are being posed ceaselessly, and the development of wavelet techniques, such as wavelet package, multi wavelet and second generation wavelets brings vitalities to the wavelet analysis. All such progress accelerates the fascinating combination of these two algorithms to get more practicable compression methods.Based on the analysis of wavelet and fractal image compression, the way of mergence of these two methods is discussed. The fusion framework can improve the coding efficiency greatly, while keeping image compression quality compared with traditional algorithms.One of the improved algorithms is the spread of the current fractal coding method based on wavelet transform, which attempts to combine the fractal coding theory and the wavelet package transformation to compress image. In detail, firstly the image is transformed by the wavelet package, then the high frequency part is compressed by traditional wavelet transformation, which utilizes the characteristic of wavelet package analysis; at the same time the low frequency part is compressed through fractal coding technique. Computer simulation shows that by taking the above-mentioned methods the calculating efficiency can be improved greatly, while the reconstructed images have similar quality compared with those got through basic fractal coding methods. It...