Image reconstruction using adaptive mesh refinement based on adaptive thresholding in electrical impedance tomography

Highlights: • An adaptive mesh refinement technique is applied to two-phase flow imaging using EIT. • An optimal threshold is automatically computed by Otsu's method. • The total number of unknown variables is reduced. • The accuracy of reconstructed images is improved using the proposed method. - Abstract: As an alternative noninvasive technique, electrical impedance tomography has been employed to visualize two-phase flows, because of its fast response for monitoring flow processes. However, it still suffers from poor resolution of reconstructed images due to non-linearity and ill-posedness of the inverse problem. To overcome this problem, in this paper, an adaptive mesh refinement method based on an adaptive threshold technique is proposed to improve the image resolution of the Gauss-Newton method without any prior information. Both numerical and experimental studies have been carried out and the results show that the proposed method has better performance as compared to the conventional method