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Many useful image processing operations may be implemented by filtering the image
with a selected filter.
Image Processing defines a large number of
smoothing, sharpening, noise reduction, and edge filters. Additional filters may be
easily added or designed using the filter design functionality of the package.
BoxFilter, GaussianFilter, and SmoothingFilter
are all variants of so-called
smoothing filters. They produce a response that is a local (weighted) average of
the samples of a signal.
The Savitzky-Golay smoothing filter is an optimal filter that returns the best average
value, in the sense of least squares, for each neighborhood of image points. It is a good
general-purpose smoothing filter. Here we show the coefficients of a Savitzky-Golay
filter of order three and length five.
This loads an example image and computes a smoothed copy using the filter shown above.
Here we display the two images.