%0 Journal Article
%T Greylevel Difference Classification Algorithm inFractal Image Compression<br>Greylevel Difference Classification Algorithm in Fractal Image Compression
%A Chen Yisong
%A Lu Jian
%A Sun Zhengxing
%A Zhang Fuyan
%A <br>陈毅松
%A 卢坚
%A 孙正兴
%A 张福炎
%J 计算机科学技术学报
%D 2002
%I 
%X This paper proposes the notion of a greylevel difference classification algorithm in fractal image compression. Then an example of the greylevel difference classification algorithm is given as an improvement of the quadrant greylevel and variance classification in the quadtree-based encoding algorithm. The algorithm incorporates the frequency feature in spatial analysis using the notion of average quadrant greylevel difference, leading to an enhancement in terms of encoding time, PSNR value and compression ratio. This work is supported by the National Natural Science Foundation of China (No.69903006).
%K image coding
%K fractal
%K classification algorithm
%K greylevel difference classification<br>图像处理
%K 灰度差分分类算法
%K 不规则图像压缩
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=5B3AB970F71A803DEACDC0559115BFCF0A068CD97DD29835&cid=8240383F08CE46C8B05036380D75B607&jid=F57FEF5FAEE544283F43708D560ABF1B&aid=A406A6F7BB83F4C1953D0D90D3126C85&yid=C3ACC247184A22C1&vid=BCA2697F357F2001&iid=0B39A22176CE99FB&sid=2B25C5E62F83A049&eid=2B25C5E62F83A049&journal_id=1000-9000&journal_name=计算机科学技术学报&referenced_num=1&reference_num=9