Posted by
Cammer, Michael on
Feb 19, 2014; 7:51pm
URL: http://imagej.273.s1.nabble.com/Circularity-error-tp5006583p5006592.html
Also, for one of the circles...
Area (pixels) Perim. Circ. Round
magic wand 2809 196.17 0.92 1
magic wand followed by Fit Spline 2756 187.3 0.99 0.99
magic wand followed by Fit Circle 2828 188.5 1 1
magic wand followed by Fit Ellipse 2809 187.82 1 1
===========================================================================
Michael Cammer, Microscopy Core & Dustin Lab , Skirball Institute, NYU Langone Medical Center
Cell: 914-309-3270 Lab: 212-263-3208
http://ocs.med.nyu.edu/microscopy &
http://www.med.nyu.edu/skirball-lab/dustinlab/-----Original Message-----
From: ImageJ Interest Group [mailto:
[hidden email]] On Behalf Of Cammer, Michael
Sent: Wednesday, February 19, 2014 2:28 PM
To:
[hidden email]
Subject: Re: Circularity error?
Hi.
I took your image of circles, thresholded it, and ran particle analyzer on it. The resulting calculated circularity looks different than your results (attached). Did you draw a circular ROI and measure it as opposed to the raster based circles? Regardsless, the Roundness was 1 for all the circles.
Regards,
Michael
===========================================================================
Michael Cammer, Microscopy Core & Dustin Lab , Skirball Institute, NYU Langone Medical Center
Cell: 914-309-3270 Lab: 212-263-3208
http://ocs.med.nyu.edu/microscopy &
http://www.med.nyu.edu/skirball-lab/dustinlab/-----Original Message-----
From: ImageJ Interest Group [mailto:
[hidden email]] On Behalf Of Adam Hughes
Sent: Wednesday, February 19, 2014 1:47 PM
To:
[hidden email]
Subject: Circularity error?
Hi,
I made an image of increasing circles to see how the circularity changed as a function of circle radius, where I used another library to draw the circles.
I discovered that if I compute the circularity using the formula 4 pi * ( area / perim**2), the result is diferent than if I plot the output of circularity. All of the values of area, perimeter and circularity were taken directly from imageJ analyze particles.
It looks like the circularty has some sort of correction in place?
I've attached the scatter pot showing these results and the test data used for the particles.
--
ImageJ mailing list:
http://imagej.nih.gov/ij/list.html------------------------------------------------------------
This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain information that is proprietary, confidential, and exempt from disclosure under applicable law. Any unauthorized review, use, disclosure, or distribution is prohibited. If you have received this email in error please notify the sender by return email and delete the original message. Please note, the recipient should check this email and any attachments for the presence of viruses. The organization accepts no liability for any damage caused by any virus transmitted by this email.
=================================
--
ImageJ mailing list:
http://imagej.nih.gov/ij/list.html------------------------------------------------------------
This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain information that is proprietary, confidential, and exempt from disclosure under applicable law. Any unauthorized review, use, disclosure, or distribution is prohibited. If you have received this email in error please notify the sender by return email and delete the original message. Please note, the recipient should check this email and any attachments for the presence of viruses. The organization accepts no liability for any damage caused by any virus transmitted by this email.
=================================
--
ImageJ mailing list:
http://imagej.nih.gov/ij/list.html