Re: bending and radius of curvature

Posted by Rasband, Wayne (NIH/NIMH) [E] on Dec 21, 2010; 4:42pm
URL: http://imagej.273.s1.nabble.com/Re-bending-and-radius-of-curvature-tp3686117p3686120.html

On Dec 21, 2010, at 5:49 AM, Norbert Vischer wrote:

> Hi Wayne and others,
>
> For closed shapes, I rather would associate "Fit Circle" to be similar to "Fit Ellipse", i.e. same area and centroid. This is currently not the case: a longish, symmetrical particle outline could result in a very large radius (see macro below). Also if I remove the "Fit Spline" in the macro, I don't understand the meaning of the resulting circle.
>
> What about applying the "Fit Circle" only to open shapes (MultiPoint, Segmented Line), while closed shapes just would return a circle with same area and centroid?
>
> Norbert Vischer
>
>
> newImage("A", "8-bit White", 550, 550, 1);
> makeOval(80, 200, 200, 50);
> setKeyDown("shift");
> makeOval(90, 220, 10, 10);//so it behaves like a traced roi
> run("Fit Spline");//optional
> run("Invert")
> wait(1000);
> run("Fit Circle");

In the 1.44m5 daily build, Edit>Selection>Fit Circle only fits a circle to open shapes (lines and points). For closed shapes, it creates a circle with the same area and centroid.

-wayne for