Feature Extraction Approach for Defect Inspection in Eddy Current Pulsed Thermography

The eddy current pulsed thermography(ECPT) technique is a research focus in the non-destructive testing(NDT) area for defect inspection. Defect feature extraction for defect information analysis in ECPT is limited by image contrast, heat diffusion, background interference, etc. In this paper, a defect feature extraction approach in ECPT has been proposed to improve the quality of defect features, which is based on image partition, local sparse component evaluation, and feature fusion. This method can extract complete defect features by enhancing the defect area and removing background interference, such as noises and heating coil. Two typical steel specimens are utilized to testify the validity of the proposed approach. Compared with other three common feature extraction algorithms in ECPT, the proposed method can reserve more complete defect features and suppress more background interference.