Re: ROI manager questions

Posted by Gabriel Landini on
URL: http://imagej.273.s1.nabble.com/Earlier-Post-tp3702702p3702706.html

On Tuesday 23 May 2006 10:42, Joachim Wesner wrote:
> I like the region manager a lot, but seem to have a problem: The manual is
> talking about (several) selected ROIs, how do it achieve that? I seem to be
> able to only highlight ONE
> of the entries in the manager window at the time. (Already tried pressing
> Shift, Ctl, Alt....)

First draw & add all the ROIs you need by pressing Shift while drawing, then
click Add in the ROI Manager. That entry contains all the previously selected
ROIs.

> Also, I would highly appreciate if in addition to "Combine" which should
> give the UNION of the selected regions it would be possible  to somehow
> create an INTERSECTION of the regions
> (i.e. to make ROIs with holes).

Not sure if this can be done, but the intersection could in principle be
obtained:
Create ROI1, store it
Create ROI2 that intersects with ROI1 but subtract it (Alt), store it as ROI3
Restore ROI1 and subtract ROI3
The result should be the intersection.

You could use a binary image of the filled ROIs to create the intersection and
then use the wand to get the result ROI.

You can make ROIs with holes and this was discussed here not long ago (with a
macro example). Have a look in the mailing list archive.

> but I would like to later finetune that hole (relative to the
> surroundings), which seems to be impossible at the time, the moment you
> release the mouse button everything will be converted into a complex
> "freestyle" ROI and you can only move the whole thing around.

Not really, one can still add and subtract to that ROI by playing with the
Shift and Alt keys.
I hope it helps.
Cheers,

Gabriel