Research On Compression Techniques Of Seismic Data Based On Lifting Wavelet Transform

In recent years, with the continuous development of society, science andtechnology continues to progress, increasing seismic exploration methods, more andmore advanced technology in the field of seismic exploration has been widely used.Seismic exploration technologies are tending to multi-parameter, multi-dimensional,multi-component, high-resolution direction to flourish. Therefore, the actualexploration, seismic also will get more data. Therefore, under the conditions existingnetwork transmission and data storage and backup, more effective solution is to usean appropriate compression algorithm, fast and efficient seismic data compression toreduce the amount of data storage and network data transfer. This paper aimed atpositioning untethered from seismic data collected in the field seismographcompressed RAW format. According to the information stored in different datasegments are different, take a different compression strategy, under the guaranteecompression useful information is not lost, put forward a high-efficiency,high-performance compression method.This paper describes the research status background and significance of the datacompression technology, the research progress and seismic data compression. Seismicdata format standards and described in detail, the characteristics of the seismic dataformat presented whole compression process, including transformation, quantizationand coding stages. Transform the way through the usual comprehensive analysis andcomparison, the final choice of lifting wavelet transform methods. For lifting wavelettransform coefficients of the low-frequency component, because it contains most ofthe seismic energy radiation should be directed lossless compression coding to ensurethe accuracy of the reconstruction of seismic data; while the high-frequencycomponent of the wavelet transform, contain more noise, so large amount of dataavailable for compression, the wavelet coefficients for the advanced band suitablechoice of the threshold value, then all wavelet coefficients of the quantization scale,and finally coded. Quantify some of the major methods by some quantitative analysis,establish a reasonable quantization table. Data compression coding part is a key aspectof this paper, several commonly used lossless compression encoding are introduced and analyzed, and based on data compression performance indicators to compare theadvantages and disadvantages of each method, considering the complexity of thesystem, the compression of time and compression ratio these elements come LZWcompression algorithm is efficient, and the algorithm is relatively simple principle.Lifting Wavelet change and eventually come to a combination of LZW coding,lossless compression to ensure the same time, with higher performance.In coding implementation process for the shortcomings of traditional LZWalgorithm itself exists to improve them, the traditional coding wasted on the length ofthe matching algorithm, taking dynamic encoding, and in the establishment andupdating the dictionary also improved. Through simulation experiments and thepre-and post-improvement encoding format for RAW seismic data compression ofdifferent sizes. Experimental results show that the improved algorithm can achievebetter compression. It not only improved the compression ratio, but also reduced thecompression and decompression time. The actual seismic data compression andreconstruction of the original signal and the comparison signal is found the error issmall, maintaining the original useful signal. The results achieved the desired goals.