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<math> | <math> | ||
| − | h(k,l)=\begin{array}{ccc}1& 2 & 1\\ | + | h(k,l)=\frac{1}{16}\left[ \begin{array}{ccc}1& 2 & 1\\ |
2 &4 &2 \\ | 2 &4 &2 \\ | ||
1 & 2 & 1 | 1 & 2 & 1 | ||
\end{array} | \end{array} | ||
| + | \right] | ||
</math> | </math> | ||
[[Image:averagefilterfrequencyresponse.png]] | [[Image:averagefilterfrequencyresponse.png]] | ||
| + | |||
| + | Plot of the frequency response of the filter: | ||
| + | |||
| + | <math> | ||
| + | h(k,l)=\frac{1}{9}\left[\begin{array}{ccc}-1& -1 & -1\\ | ||
| + | -1 &8 &-1 \\ | ||
| + | -1 & -1 & -1 | ||
| + | \end{array} | ||
| + | \right] | ||
| + | </math> | ||
| + | with <math>\lambda = 0.5</math>. | ||
[[Image:edgedetectfilterfrequencyresponse.png]] | [[Image:edgedetectfilterfrequencyresponse.png]] | ||
| + | |||
| + | Plot of the frequency response of the filter: | ||
| + | |||
| + | <math> | ||
| + | h(k,l)=\frac{1}{9}\left[\begin{array}{ccc}-\lambda & -\lambda & -\lambda\\ | ||
| + | -\lambda &9+8 \lambda & -\lambda \\ | ||
| + | -\lambda & -\lambda & -\lambda | ||
| + | \end{array} | ||
| + | \right] | ||
| + | </math> | ||
[[Image:unsharpmaskfrequencyresponse.png]] | [[Image:unsharpmaskfrequencyresponse.png]] | ||
| − | [http://en.wikipedia.org/wiki/Unsharp_masking | + | == Links == |
| + | *[http://en.wikipedia.org/wiki/Unsharp_masking Example of unsharp masking applied to eye image] | ||
| + | *[http://www.focusmagic.com/exampleunsharpmask.htm Illustrations of grainy effects caused by unsharp mark] | ||
Latest revision as of 11:52, 28 April 2009
Plot of the frequency response of the average filter:
$ h(k,l)=\frac{1}{16}\left[ \begin{array}{ccc}1& 2 & 1\\ 2 &4 &2 \\ 1 & 2 & 1 \end{array} \right] $
Plot of the frequency response of the filter:
$ h(k,l)=\frac{1}{9}\left[\begin{array}{ccc}-1& -1 & -1\\ -1 &8 &-1 \\ -1 & -1 & -1 \end{array} \right] $ with $ \lambda = 0.5 $.
Plot of the frequency response of the filter:
$ h(k,l)=\frac{1}{9}\left[\begin{array}{ccc}-\lambda & -\lambda & -\lambda\\ -\lambda &9+8 \lambda & -\lambda \\ -\lambda & -\lambda & -\lambda \end{array} \right] $
