基于整数小波变换的漏磁信号压缩方案

Signal Compression Plan of Magnetic Flux Leakage Testing Based on Integer Wavelet Transform

提出一种用于漏磁信号的数据压缩方案。方案由整数小波变换、改进SPIHT编码和自适应算术编码组成。整数小波变换无需浮点运算,算法简单,易于实现。将SPIHT算法与自适应算术编码结合应用于一维漏磁信号压缩,可以实现高压缩比、多种码率压缩编码。使用通过低通滤波器预处理的漏磁信号数据对该方案进行了测试。结果表明,该方案在得到高压缩比和低计算复杂度的同时可以保持较低的失真度,可满足在线漏磁检测系统的数据压缩要求。

An encode/decode compression system applied in magnetic flux leakage testing （MFLT） was presented. This system combined integer wavelet transform, improved SPIHT（Set Partitioning in Hierarchical Trees） algorithm and adaptive arithmetic coding scheme. The algorithm could be implemented without floating computing and had excellent features of low comp!exity and high efficiency. Combined with adaptive arithmetic coding scheme, SPIHT algorithm modified for the one-dimensional case could compress signals with the property of high compression ratio and progressive encoding. MFL signals treated with the low-pass filter were used to test the system. Experimental results showed that this method was effective in high compression ratio and signal fidelity. So the system was useful for online MFL testing.