摘要
有效的压缩算法可以给数据的储存和传输带来极大的方便.针对现有压缩算法存在的不足,定义图像子块的九块和特征,并提出结合小波和分形编码优势的有损压缩算法.该算法将图像进行二级小波分解,得到7个子带;保留低频子带的小波系数,并对其余子带采用基于图像块九块和特征的分形编码.新定义的九块和算法,把全搜索问题变为在九块和意义下的近邻搜索问题,缩短了搜索范围.实验结果表明,与同类算法相比,该算法不仅提高了重构图像的质量,还缩短了编解码时间.
Effective compression algorithms can bring great convenience to the storage and transmission of data.Aiming at the shortcomings of existing compression algorithms,nine blocks and features of image sub-blocks were defined,and we proposed a lossy compression algorithm combining wavelet and fractal coding advantages.The image was decomposed by the second-order wavelet,and 7 sub-bands were obtained.Then the wavelet coefficients of the low-frequency sub-band were preserved,and the remaining sub-bands were fractal coded based on image block features of nine pieces sum.The newly defined nine pieces sum algorithms turned the full search problem into a neighbor search problem in the nine pieces sum,shortening the search range.Experimental simulations show that the algorithm not only improve the quality of reconstructed images,but also shorten the encoding and decoding time compared with similar algorithms.
作者
赵蓉
王辉
张爱华
Zhao Rong;Wang Hui;Zhang Aihua(College of Physics,Nanjing University of Posts and Telecommunications,Nanjing 210023,Jiangsu,China)
出处
《计算机应用与软件》
北大核心
2019年第11期262-266,305,共6页
Computer Applications and Software
基金
国家自然科学基金面上项目(11471114,61372125)
江苏省自然科学基金项目(BK20160800)
关键词
分形
图像压缩
九块和
小波
Fractal
Image compression
Nine pieces sum
Wavelet
