Abo-Zahhad Mohammed, Rajoub Bashar A
Electronics Engineering Department, Hijjawi Faculty for Engineering Technology, Yarmouk University, Irbid, Jordan.
Med Eng Phys. 2002 Apr;24(3):185-99. doi: 10.1016/s1350-4533(02)00004-8.
This paper introduces an effective technique for the compression of one-dimensional signals using wavelet transforms. It is based on generating a binary stream of 1s and 0s that encodes the wavelet coefficients structure (i.e., encodes the locations of zero and nonzero coefficients). A new coding algorithm, similar to the run length encoding, has been developed for the compression of the binary stream. The compression performances of the technique are measured using compression ratio (CR) and percent root-mean square difference (PRD) measures. To assess the technique properly we have evaluated the effect of signal length, threshold levels selection and wavelet filters on the quality of the reconstructed signal. The effect of finite word length representation on the compression ratio and PRD is also discussed. The technique is tested for the compression of normal and abnormal electrocardiogram (ECG) signals. The performance parameters of the proposed coding algorithm are measured and compression ratios of 19:1 and 45:1 with PRDs of 1% and 2.8% are achieved, respectively. At the receiver end, the received signal is decoded and inverse transformed before being processed. Finally, the merits and demerits of the technique are discussed.
本文介绍了一种使用小波变换压缩一维信号的有效技术。它基于生成一个由1和0组成的二进制流，该二进制流对小波系数结构进行编码（即对零系数和非零系数的位置进行编码）。已开发出一种类似于游程编码的新编码算法，用于压缩该二进制流。使用压缩率（CR）和均方根误差百分比（PRD）指标来衡量该技术的压缩性能。为了正确评估该技术，我们评估了信号长度、阈值水平选择和小波滤波器对重构信号质量的影响。还讨论了有限字长表示对压缩率和PRD的影响。该技术针对正常和异常心电图（ECG）信号的压缩进行了测试。测量了所提出编码算法的性能参数，分别实现了19:1和45:1的压缩率，PRD分别为1%和2.8%。在接收端，对接收到的信号进行解码和逆变换后再进行处理。最后，讨论了该技术的优缺点。
