Image Denoising for Phased Array Total Focusing Based on Wavelet Transform

In order to solve the problem of the imaging background noise of the phased array total focusing method, this paper presents a method to eliminate the noise of phased array total focusing method image based on wavelet transform. The focusing image signal is decomposed into wavelet domain by the discrete wavelet transform, and the high frequency sub band transformed coefficients is subjected with adaptive threshold processing based on unbiased risk estimation. Inverse wavelet transform is then implemented on the processed high and low frequency sub band coefficients, and hence total focusing method image is reconstructed. The experimental results show that the proposed method can effectively remove the background noise of the total focusing method image, and retain the real defect signal inside the inspected workpiece.