Lossless Compression of Pipeline Magnetic Flux Leakage Inspection Data Based on Region of Interest
Lijian Yang, MA Feng-ming, Songwei Gao · 2006
A pipeline MFL (Magnetic Flux Leakage) inspection device with high resolution generates a great deal of data, so it is necessary to compress the real-time data. The characteristics of MFL inspection data was analyzed, the inspection data was preprocessed to eliminate the effect of sensor lift-off and the preprocessed MFL image was segmented to ensure the ROI (Region of Interest). Integer wavelet transform was applied to the ROI and Wavelet coefficient which was lifted by the max shift method and combined with SPIHT(Set Partitioning in Hierarchical Tree) code algorithm realizes the lossless compression of MFL image ROI and compression ratio is over 8:1.