Computer enhancement of scanning electron micrographs

This paper deals with the digital restoration of scanning electron micrographs. The properties of the signal and noise generated when recording a micrograph are analyzed and used to develop the optimal Wiener filter for enhancing the image. The transfer function of the display device, as well as the frequency foldover produced by sampling the image are included in the model. The mean-square-error measure is used in deriving the optimal filter, and it is shown that weighting this measure to reflect the spatial frequency response of the eye is of no benefit. A number of micrographs illustrate the success of restoration at different magnifications. In the opinion of some microscopists, the computer enhancement has produced significant, although not dramatic, improvements in the quality of the images.