On the use of discrete Laplacian operators in image restoration

The role of the stabilizing functional in the Tikhonov (1964) regularization is as crucial as that of the regularization parameter. However, a 3/spl times/3 discrete differential operator is usually used to generate the stabilizing functional. It is demonstrated that the restoration quality is practically independent of the size of the generating stabilizing operator. As a result, the choice of small size of the generating stabilizing operator is justified. Moreover, this observation leads to the advantage that spatial-domain implemented filters can be designed within a reasonable small order.