Re: Problem with area measurement

Posted by Laura DiNicola on Jul 19, 2005; 11:10pm
URL: http://imagej.273.s1.nabble.com/Problem-with-area-measurement-tp3705217p3705219.html

are you sure it is counting the holes?  i had a similar problem, and all i did was threshold the image, reselect it by clicking on the black area on the outside with the wand tool, and use the analyze particles tool.  i know this worked because i double checked it by using the measure->area tool and then held alt down while clicking the wand in the white areas.  each time i measured it, the area was smaller, and when i clicked on all of the white areas, i got the same number as i did with the analyze particles tool.  




 --- On Tue 07/19, Gabriel Landini < [hidden email] > wrote:
From: Gabriel Landini [mailto: [hidden email]]
To: [hidden email]
Date: Tue, 19 Jul 2005 22:50:31 +0100
Subject: Re: Problem with area measurement

On Tuesday 19 July 2005 20:02, kevin egan wrote:<br>> I have been having a problem with the Analyze particles tool in Image<br>> J. If the area I am measuring has any fully enclosed white spaces<br>> (after thresholding the image), it measures these areas as being part<br>> of the  black areas. <br><br>Not sure what the problem is (I am writing this off-line), but if you want to <br>measure a blob without the holes, you could do:<br><br>1. Use the Analyze Particles to get the area of the blob, then invert the <br>image and measure the area of the holes and subtract this value from the <br>other.<br><br>2. Use one of the plugins Particles4, Particles8, or  Particles8_plus in the <br>Morphology collection (below). These give you the *number of pixels* of a <br>blob, taking into accout any holes. <br>http://www.dentistry.bham.ac.uk/landinig/software/software.html<br><br>I hope it helps.<br><br>G.<br>

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