Noise-Reduction Software
So far, I’ve concentrated on how noise occurs, what it looks like, and the problems of detecting it. With all types of noise-reduction software, there are two principal steps.
The first is detection, selecting those pixels considered to be rogue artifacts. The second, which we’ll now look at, is the procedure for replacing them. At pixel level, noise is not simply removed, because that would leave a pattern of “holes,” whatever their color. It has to be replaced with values that blend it into its surroundings. The simplest way is to use a blurring filter, which has the effect of smearing the pixel values over a chosen radius. A Gaussian Blur filter is the standard, default means of digital blurring, although for noise ...
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