Re: Measurement of Feret diameter
Posted by Geology Guy on
URL: http://imagej.273.s1.nabble.com/Measurement-of-Feret-diameter-tp5003818p5003955.html
>>
>> The computation of ferets already involves rotation - you can see the details in the source code for ShapeRoi. The rotation is divided into 2 degree increments - which is different than "all different possible angles". Getting the latter would require a good deal of patience.
>>
>> http://rsb.info.nih.gov/ij/developer/source/ij/gui/ShapeRoi.java.html
>>
>> Are you looking for a representative size measurement?
>>
>> Cheers,
>> Ben
Dear Ben,
What I am trying to measure are 2D images of particles that are clustered like raspberries (particles within the yellow boundary in the image attached). I am doing a project with my Professor and he wants me to use Feret's diameter as one of the criteria for measuring the size of the individual crystals in the cluster, as well as the size of the cluster (framboid) itself. So I will go by the formula for calculating the Feret diameter that Michael suggested above. The only other question I have is that if you look at the "Fit Ellipse" in image J, it gives only a major and minor axis measurement. In order to use Fit Ellipse to measure size, I assume I just have to multiply the major and minor axis?
Thanks a lot for responding on time.
URL: http://imagej.273.s1.nabble.com/Measurement-of-Feret-diameter-tp5003818p5003955.html
>>
>> The computation of ferets already involves rotation - you can see the details in the source code for ShapeRoi. The rotation is divided into 2 degree increments - which is different than "all different possible angles". Getting the latter would require a good deal of patience.
>>
>> http://rsb.info.nih.gov/ij/developer/source/ij/gui/ShapeRoi.java.html
>>
>> Are you looking for a representative size measurement?
>>
>> Cheers,
>> Ben
Dear Ben,
What I am trying to measure are 2D images of particles that are clustered like raspberries (particles within the yellow boundary in the image attached). I am doing a project with my Professor and he wants me to use Feret's diameter as one of the criteria for measuring the size of the individual crystals in the cluster, as well as the size of the cluster (framboid) itself. So I will go by the formula for calculating the Feret diameter that Michael suggested above. The only other question I have is that if you look at the "Fit Ellipse" in image J, it gives only a major and minor axis measurement. In order to use Fit Ellipse to measure size, I assume I just have to multiply the major and minor axis?
Thanks a lot for responding on time.
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