(New page: Plot of the frequency response of the average filter: <math> h(k,l)=\begin{array}{ccc}1& 2 & 1\\ 2 &4 &2 \\ 1 & 2 & 1 \end{array} </math> Image:averagefilterfrequencyresponse.jpg ...) |
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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. | + | [[Image:averagefilterfrequencyresponse.png]] |
− | [[Image:edgedetectfilterfrequencyresponse. | + | 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]] | ||
+ | |||
+ | 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. | + | [[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] $