Research On Embedded Image Coding Algorithm Based On Wavelet And Fractal

The rapid development of multimedia technology enables the image coding to be one of the most active researches in the information field, in which the method based on wavelet analysis is the most prominent.Wavelet analysis is a time-frequency analysis method dealing with non-transition signals, which is based on multi-resolution. It overcomes the shortcoming of Fourier analysis, which can not reflect the locality of time domain. But its nature is based on the theory of information entropy, so it can not break the limit of entropy. Fractal is a new nonlinear theory in recent decades and it is used widely in many fields, especially in image compression. Because of its overcoming the limit of entropy, high compression rate can be obtained.Wavelet theories, image coding based on wavelet, and fractal theory are studied in the paper. Considering the long time of fractal compression in time domain, a new method is proposed based on image partition, which reduces the time effectively. Meanwhile, a new means which is based on fractal dimension is provided for selecting suitable wavelet base to encode an image, so it can enhance the efficiency of encoding. In the end, a mixed image coding method is given in order to improve the low compression rate based on wavelet and reduce the time cost by fractal methods. According to the results of experiments, encoding time is reduced greatly and the quality of reconstruction image is ensured.