基于方位信息的改进LZW前缀编码方案  

Improved LZW Prefix Coding Scheme Based on Azimuth Information

作　　者：韩宾[1] 张红红 江虹[1] 丁一 HAN Bin;ZHANG Hong-hong;JIANG Hong;DING Yi(College of Information Engineering,Southwest University of Science and Technology,Mianyang,Sichuan 621010,China)

机构地区：[1]西南科技大学信息工程学院

出　　处：《计算机科学》2019年第8期157-162,共6页Computer Science

基　　金：国家自然科学基金项目(51475453);西南科技大学研究生创新基金(18ycx118)资助

摘　　要：LZW压缩算法在实时采集与无线传输中具有重要应用价值,一般采用采集-压缩-传输的工作模式,该模式下的较高压缩比可极大降低对无线传输的压力。但在采集速度较快、数据传输带宽较低、硬件资源受限的情况下,在对采样点概率分布较均匀的数字信号进行压缩时,易出现压缩率不高或采集速度与压缩速度不匹配的问题。对此,文中提出了基于方位信息的改进LZW前缀编码方案。该改进压缩算法基于压缩比因子对采样点进行映射操作,使其能够标识后面相邻采样点的压缩情况,然后通过采样点间的方位信息,缩短采样点的码长,实现对采样点数据的压缩。实验表明,与原LZW压缩算法相比,该改进算法在不增加算法复杂度和硬件存储空间的条件下,压缩比可提高26.25%,证明了该算法在采集系统中的有效性。LZW compression algorithm has important application value in real-time acquisition and wireless transmission.Generally,it adopts the acquisition-compression-transmission working mode,and high compression ratio in this mode can greatly reduce the pressure on wireless transmission.But in the case of fast acquisition speed,low data transmission bandwidth and limited hardware resources,it can easily lead to problems that the compression rate is not high or the speed of acquisition is mismatched when compressing the digital signal which has a sampling point of uniform probability distribution.To this end,this paper proposed an improved LZW prefix encoding scheme based on azimuth information.Firstly,the improved compression algorithm maps the sampling points based on compression ratio factor,so that it can identify the compression condition of adjacent sampling points.Secondly,through the azimuth information between the sampling points,the code length of the sampling points is shortened,so the data of the sampling points is compressed.Experiments show that,compared with the original LZW compression algorithm,the improved algorithm can increase the compression ratio by 26.25%without increasing the complexity and hardware storage space.Therefore,the effectiveness of the algorithm in the acquisition system was proved.

关 键 词：LZW算法 方位信息 数字信号 映射 编码 

分 类 号：TP301.6[自动化与计算机技术—计算机系统结构]