| As a powerful tool of new mathematics,fractal geometry can complete the irregular graphics depicting,and make it become one of the directions of the image compression coding.However,fractal image encoding takes a long time to search for a matching block,and the encoding process can produce the blocking effect and affect the clarity of images.So,under the precondition of ensuring the image quality is not reduced,improving the image encoding speed has become the research topic to be discussed.Specific activities include the following:Firstly,based on the basic eigenvector method and fractal algorithm,a new sub-block feature representation method(sum of double cross eigenvalues)is proposed to define the norm block,the codebook is sorted by the new features,and the matching search is carried out by the best matching block which is found in the codebook.A fast fractal image coding algorithm based on sum of double cross eigenvalues is proposed,the outcome of experiments proves that the algorithm can effectively improve the coding speed without effect the quality of images.Secondly,a new range feature representation is used for each sub-block,and the best matching block is searched by the adaptive search method.The feasibility analysis is given and an adaptive search fractal image coding algorithm based on range feature is proposed.The contrast experiments prove that this algorithm performs well on the issue of rebuilding image quality and image compression coding time.Finally,based on the cross-trace feature algorithm and the minimum mean square error and the cross-trace inequality,a new algorithm which is a new feature of the interval cross-trace is proposed.The new matching algorithm is used to reduce the searching time of the best matching block.The results of this experiment means that compared with the general feature of the cross-trace,the algorithm for image processing time is less than others,and reconstructed image quality is also guaranteed. |
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