Image Restoration with a Locally Variable Wiener Filter

摘要

The parametric Wiener filter is often used to deblur images that are relatively noise-free.If noise is more severe, the restored image may be obscured by a granular pattern that results when the noise is subjected to the deblurring filter. This effect may be reduced by using a larger noise parameter, but this leads to a restoration that is less sharp. Variation of the noise parameter from pixel to pixel so that it is larger only where noise is greater is described. Pixels with low singnal-to-noise ratios are identified by a thresholding process and comparison with nearest neighbors. The effects of the estimated Wiener spectra on the restored image are discussed. 14 figures. (ERA citation 04:038024)