A Note on Image Restoration Using $C_{p}$ and MSE

Image restoration necessitates the choice of a regularization parameter that controls the trade-off between fidelity to the blurred noisy observed image and the smoothness of the restored image. The choice of this parameter for which several estimators have been proposed is crucial for the quality of the restored image. In this letter, two estimators for choosing the regularization parameter are proposed. One is a simple closed-form approximation to the minimum of the selection criterion, and the other is an approximation to the minimum of a mean squared error (MSE)-based criterion.