Development of image fusion methodology using discrete wavelet transform for eddy current images

In this paper, a method based on the discrete wavelet transform is proposed for eddy current image fusion. This method mainly involves two steps: selection of the proper wavelet filters and level of decomposition using formulated parameter, and selection of the proper fusion criterion in wavelet sub-band. The main aspect of the proposed method concentrates on elimination of noise while retaining defect information. This method fuses the eddy current images at two different frequencies from stainless steel cladding tube, in order to take the advantage of deep lying information effectively. The fusion results show that the selection of wavelet and fusion rule reduces the ambiguity and enhances the reliability of defect detection in both visual and qualitative evaluation.