Application of two dimensional spectral estimation in image restoration

In this paper we consider an application of spectral estimation to adaptive restoration of images degraded by additive white noise. Three adaptive techniques of restoration are compared with a non-adaptive technique. In the non-adaptive technique, the whole image is Wiener filtered by assuming a correlation model for the signal. In the adaptive methods, a) the spectral shape of the signal is kept constant, but the variance is adaptively estimated, b) the power spectrum of each block is adaptively estimated, c) the data is adaptively decorrelated in one dimension and filtered along the other.