Drawing non-orthogonal ellipses....and measure "ellipse" question

Hi all,

is there any supported macro way to (easily) create an ellipse overlay that isn’t orthogonal to the axes? (ie has a rotation specified)

My ultimate goal here is to use measure to identify the best fit ellipse on a selection, and then draw the resulting fitted ellipse back over the image …but it’s proving a bit of a problematic task

I searched and there doesn’t seem to be directly in the supported macro functions.

I did manage to modify an idea here (http://imagej.1557.x6.nabble.com/makeEllipse-defined-by-angle-td4999674.html) for using selection->specify to create an oval selection, then using rotate on that to rotate the selection an arbitrary amount, then using Overlay-> add selection to finally get it into an overlay. …cool idea, if a bit convoluted (I hadn’t seen Overlay->specify before!)

Here’s a rough bit of code that illustrates it:

run(“Specify…”, “width=100 height=150 x=228 y=228 oval centered”);
run(“Rotate…”, “angle=33”);
run(“Add Selection…”)

But the problem with this is there doesn’t seem to be a way to specify the line width or color of the overlay item above - they’re always yellow and 0 width! (setLineWidth and setColor don’t seem to apply when you use “add selection”).

…is there a way to modify an overlay’s color and line width from a macro after it’s created?

My second question is about using measure, with “ellipse” specified, to do a best fit ellipse to a current region. The ellipse measurements returned are major/minor axis lengths and angle.
…but what is the ellipse centre? is it the region’s centroid values?

My ultimate goal here is to use measure to identify the best fit ellipse on a selection

Please study the ImageJ User Guide.
(Edit >> Selection >> Fit Ellipse)

…is there a way to modify an overlay’s color and line width from a macro after it’s created?

Yes, please study the ImageJ User Guide.
(Image >> Overlay >> Overlay Options…)

…but what is the ellipse centre? is it the region’s centroid values?

Yes, of course.
Why don’t you simply try?

Regards

Herbie