Research On Fractal-based Image Compression Coding Method

In real life,many images are similar.The compression coding algorithm based on the similarity between image parts and whole and between parts is called fractal image compression coding algorithm,which has attracted much attention due to its high compression ratio and good image recovery quality.However,in the coding process,the basic fractal image coding algorithm needs to spend a large amount of time to carry out global search,which is not conducive to the improvement of coding efficiency.In addition,the shortened codebook used to shorten the coding time will lead to the block effect of image recovery.Therefore,researchers have been making unremitting efforts to ensure the quality of fractal image decoding and recovery while using less coding time.Based on the above problems,this paper carries out research,and the specific work is as follows:First,on the basis of the basic fractal block image coding,the centroid feature is used to classify the image block,and the similarity matching between the range block and definition block is transformed into the centroid feature matching between the range block and definition block,so as to simplify the matching process and effectively eliminate the unqualified definition block.According to this,a fast fractal image compression coding algorithm based on centroid feature classification is proposed,and the feasibility of the algorithm is proved by the formula.Secondly,the image centroid feature is improved,and a weighted centroid feature is adopted.Compared with the centroid feature,the image block can be characterized with more detailed features,improving the precise classification,and giving the algorithm feasibility proof.The experiment with a weighting coefficient of 2 shows that the fractal image compression coding algorithm based on the weighted centroid feature has a stronger quality improvement capability than the centroid feature,and has an advantage in improving the quality of the restored image.Finally,the fractal image compression algorithm based on feature classification is applied to medical image compression,the human body in the medical image has obvious fractal similar characteristics,through the test results show that compared withother compression algorithms,fractal image compression algorithm based on feature classification in the coding phase less time consumption,also guaranteed recovery image quality.