栅格电子地图的无损压缩新方法New lossless compression approaches for raster map
李云锦,梁鹏
摘要(Abstract):
JBIG在压缩灰度或彩色图像时,需要将图像分解为多个位面,编解码效率低而且难以利用位面之间的相关性。文章提出了RBMA方法,首先将像素值转换为引用值,然后使用多重算术编码压缩引用值,避免了位面分解。实验表明,RBMA方法与JBIG相比不仅成倍提高了编解码效率,而且提高了约40%的压缩比。GIF以一维的形式编码像素,在处理相同颜色区域时存在字典条目长度增长缓慢的问题。本文提出的LZWB方法将具有相同颜色的区域特殊编码,只输出色块的颜色、色块宽度与高度。实验表明,LZWB提高了约20%的压缩比,解码速度约为GIF的3.7倍。
关键词(KeyWords): 数据压缩;电子地图;算术编码;栅格数据
基金项目(Foundation):
作者(Author): 李云锦,梁鹏
DOI: 10.16251/j.cnki.1009-2307.2014.09.023
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