Study On Compression Method Of Pipe Leak Detection Data

At present, the total length of long-distance oil and gas pipelines have been more than 20 thousand kilometers in China, and the pipeline transportation plays an important role in our economy and industry. However, with growth gradually increased domestic oil and gas pipelines, the pipeline can not avoid aging, corrosion, and various man-made cause, the gas and oil leak had occurred. It is necessary to manage the pipeline maintenance and leak detection, to protect the normal operation of oil and gas pipelines. As the number of oil and gas pipeline detection equipments are larger, and the detection is real-time, so the detection data obtained in the course is great. Large amount of detection data will affect the network transmission speed, and it will occupy a large storage space. So design an efficient data compression method has important practical significance.Considering the problems above, this paper proposed a SPIHT coding method for the compressing the pipeline leak detection data. The method uses wavelet transform on pipeline leak detection data to remove the correlation between the signals to reduce the redundancy of the signal, then used the SPIHT coding for compressing pipeline leak detection data. Then this paper proposed a proved SPIHT coding method based on integer wavelet transform to solve the faults of initial SPIHT.The main work done as follows:1. Some basic theories were discussed which included definition, technology method, evaluation standard about data compression and etc.And the significance and the background of the compression of pipeline leak detection data were also discussed.2. The data compression method based on wavelet transform were deeply learned and studied, on the basis on which a pipeline leak detection data compression method was proposed. This method is mainly converted the 1-D pipeline leak detection signal to two-dimensional signal, then did the 2-D wavelet transform to remove the correlation between the signals in order to reduce redundancy. Finally, compressed and decompressed 2-D wavelets transform coefficients by SPIHT. In the method, it sent the larger wavelet coefficients priority as an important coefficient and then sent the smaller absolute value of wavelet coefficients as a non-significant coefficient as a priority, by a greater compression ratio and smaller reconstruction error.3. A deeply study of pipeline leak detection data collected on actual project was done. Analyzed the characteristics of the Pipeline leak detection data, and apply the proposed coding method was verified by a good result.4. The traditional SPIHT coding repeated operations and take a lot of storage space to store the LIS, LIP, LSP list. This will lead to high complexity and cost more time. Considering the problems above, this paper proposed a improved SPIHT coding based on integer wavelet transform. This method results in coding efficiency and compression to achieve more satisfactory results, can adapt to real-time pipeline leak detection compression and storage.