阈值改进整数小波与LZW算法相结合的水声数据压缩方法  

An underwater acoustic data compression method using improved threshold integer wavelet and LZW algorithm

作　　者：卓颉[1] 张怡[1] 刘雄厚[1] 刘宗伟[1] 

机构地区：[1]西北工业大学声学工程研究所,陕西西安710072

出　　处：《声学技术》2015年第2期115-120,共6页Technical Acoustics

基　　金：国家自然科学基金资助项目(11104222)

摘　　要：提出一种阈值改进整数小波与基于字典编码的LZW(Lempel-Ziv-Welch)算法相结合的数据压缩方法,该方法旨在减少水声数据传输量的同时尽可能地达到高保真。数据压缩过程中,先对水声数据进行整数小波变换,再对变换后的高频系数采用改进的小波阈值算法和阈值函数进行处理,提高了数据压缩倍数和信噪比,降低了误差。最后通过LZW将处理后的系数进行编码输出,进一步提升压缩效果。文中给出了相应的数据压缩算法流程。实际舰船辐射噪声数据的压缩处理结果表明,该方法能有效提高信号信噪比、减少信号失真并能获得更大的压缩倍数。A new data compression method is proposed in this paper, which combines the improved threshold integer wavelet with LZW algorithm. Firstly, by using wavelet transform, the sampled underwater acoustic data are decom- posed into low- and high-frequency coefficients. Then, after improved threshold processing to high frequency coeffi- cients, the ones above the threshold are remained, thereby reducing the data amount effectively. Finally, the low-frequency coefficients and remained high-frequency ones are coded by LZW coding and transmitted subsequently. The compression algorithm process is given in the paper. By processing the real ship noise data, the new method can effectively improve SNR, reduce signal distortion level and achieve higher compression ratio, compared with the con- venfional threshold value method.

关 键 词：信号压缩 整数小波变换 LZW算法 阈值 阈值函数 

分 类 号：TB688[一般工业技术—制冷工程]