Re: subtraction of ROIs

Posted by Mark R. Besonen on Jun 05, 2007; 4:50pm
URL: http://imagej.273.s1.nabble.com/subtraction-of-ROIs-tp3699147p3699159.html

Hi Javier,

         You are absolutely right--I just tried
what I suggested, and had the same result as you,
so my suggestion was incorrect.  Gabriel's
solution, however, does work.  Sorry for not
testing first--I have been using the method I
wrote for the last couple of weeks as sort of a
clipping path for overlapping regions, not ones
that were completely contained within another.  I should have tested first!

Mark Besonen
UMass Geosciences


At 11:11 AM 6/5/2007, F Javier Diez Guerra wrote:

>Mark,
>
>Thanks for your input. However, I do not manage
>to get the ring ROI after selecting it with the
>magic wand. I imagine that since the selection
>is closed, the magic wand takes the whole area
>of the bigger ROI again and not the difference.
>
>Thanks,
>
>
>At 16:46 05/06/2007, you wrote:
>>At 09:33 AM 6/5/2007, you wrote:
>>>How can I make a ROI that is the result of the subtraction between two ROIs?
>>>
>>>Searching docs and list archives I've only
>>>found how to make "composite selections",
>>>which are created by hand (by drawing a ROI
>>>inside another, while pressing the alt key).
>>>
>>>I have two ROIs in the ROI manager, one ROI
>>>inside the other one. I want to select the
>>>area within the bigger ROI, excluding the area
>>>of the smaller ROI. If we were talking of two
>>>circles (one inside the other), I want select
>>>the area defined by the ring between them.
>>>
>>>Any suggestions?
>>
>>Hello Javier,
>>
>>Here's one solution of probably many:
>>
>>Load the bigger ROI, then use
>>Edit-->Selection-->Create Mask.  On the new
>>mask window that pops up, load the second
>>smaller ROI, then use Edit-->Clear.  Now use
>>the Wand tool to automatically highlight the
>>remaining ring region, and then add that to the RoiManager.
>>
>>Mark Besonen
>>UMass Geosciences
>>
>>
>>
>>
>>>F Javier Diez-Guerra, PhD
>>>Profesor Titular
>>>Centro de Biologia Molecular Severo Ochoa
>>>Facultad de Ciencias, Universidad Autónoma
>>>Ctra Colmenar Viejo Km 15
>>>Cantoblanco, 28049 Madrid
>>>SPAIN
>>>
>>>phone:  [phone]
>>>Fax:      [phone]
>>>e-mail: [hidden email]
>>
>>F Javier Diez-Guerra, PhD
>>Profesor Titular
>>Centro de Biologia Molecular Severo Ochoa
>>Facultad de Ciencias, Universidad Autónoma
>>Ctra Colmenar Viejo Km 15
>>Cantoblanco, 28049 Madrid
>>SPAIN
>>
>>phone:  [phone]
>>Fax:      [phone]
>>e-mail: [hidden email]

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Mark R. Besonen               e-mail:  [hidden email]
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