Posted by
Michael Schmid on
URL: http://imagej.273.s1.nabble.com/How-to-create-symmetric-selection-in-FFT-image-tp5005720p5005723.html
Hi Jürgen,
if you do filtering by setting some areas in an FFT display black or white and doing a backward transform, ImageJ takes care of adding the mirrored black or white areas automatically. Thus, usually you need not care about adding the mirror yourself.
By the way, ImageJ also smooths the mask to avoid 'ringing'.
If you need a selection for some other purpose and you want to invert it:
To make the inverse of both selections, add both, the original and the inverted to the Roi Manager and then run More>>Or (Combine). In a macro, this is roiManager("OR");
Then you can run("Make Inverse");
Michael
________________________________________________________________
On Nov 27, 2013, at 22:27, Jürgen Gluch wrote:
> Does anyone know a macro/plugin code how to mirror a selection to make a
> symmetric selection in an FFT image for filtering?
> I draw some circles on a FFT and want to get the corresponding circles on
> the other side of the image center.
>
> I found this short macro from Jerome:
>
> roiManager("Add");
> getSelectionCoordinates(xs,ys);
> m=getWidth()/2;
> for (i=0;i<xs.length;i++) {
> xs[i]=m-(xs[i]-m);
> ys[i]=m-(ys[i]-m);
> }
> makeSelection ("polygon",xs,ys);
> roiManager("Add");
>
> which makes a corresponding ROI, but the ROI is not a selection and I can
> not run 'run("Make Inverse");' on it for example. So I am stuck here...
> Please help me. Jürgen
>
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