Cosine transform based preconditioners for total variation deblurring
Raymond Hon-Fu Chan, Tony Fan-Cheong Chan, Chiu-Kwong T. Wong · IEEE Transactions on Image Processing · 1999
In PDE image restoration problems, one has to invert operators which is a sum of a blurring operator and an elliptic operator with highly varying coefficient. We present a preconditioner for such operators, which can be used with the conjugate gradient (CG) method, and compare it with Vogel and Oman's (see SIAM J. Sci. Stat. Comput., vol.17, p.227-38, 1996, and IEEE Trans. Image Processing, vol.7, p.813-24, 1998) product preconditioner.