用小波变换法定量压缩地震数据

应用模型数据对 3种常用无损压缩数据方法进行了测试 ,得到的压缩比在 1.5左右 ,不足以满足实际数据压缩要求。为此提出了一种利用小波变换定量压缩地震数据的方法 ,并重点分析了小波方法的压缩比与分解的通道数、能量比与压缩效果以及压缩比与镜像滤波器长度间的定量关系。对模型资料和实际资料的测试结果表明 :①在数据压缩的多种方法中 ,小波变换法有很强的变焦功能 ,比一般的压缩方法具有更高的压缩率 ,数据压缩比达到 2 1时 ,仍能取得较理想的压缩效果 ;②在满足分解次数的条件下 ,应尽量选取较多的通道数 ;③压缩效果可以用能量比来描述 ,对于地震资料的有效压缩 ,能量比值应大于 80 % ;④在小波压缩中 ,一般应取较长的镜像滤波器 ,但并不是越长越好 ,一般在 10个点以上即能满足要求。

Quantitative compression of seismic data with wavelet transformation method

With the development of seismic exploration technique,the seismic data become more and more. The more data have to be compressed in the practical application. A wavelet transform method for compressing the seismic data was put forward. The relationships between the compression ratio with the number of decomposition channels and the length of mirror filter, as well as the energy ratio with the compression effect were discussed. The tests on the modeling and actual seismic data show that the wavelet transform is an excellent method for data compression. Even if the compression ratio reaches 21, a satisfactory result can also be obtained. The number of decomposition channels should be selected as many as possible under the condition of decomposition number being satisfied. In order to compress seismic data efficiently, the energy ratio should be reached to 80 percent. The length of mirror filter should be over 10 points, when using the wavelet transformation method to compress the seismic data.