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Re: Multiple Object Length Measurement

Posted by Mark J. Chopping on Jan 28, 2016; 5:35pm
URL: http://imagej.273.s1.nabble.com/Multiple-Object-Length-Measurement-tp5015476p5015477.html

Hi Nicholas,

Try this in a macro:

1. rotate your image so that the corn ears are aligned vertically (as far
as possible);

2.  use your preferred segmentation to isolate the ears w/thresholding;

3. use the Particle Analyser to put a box around each object (this is a
really neat function of the Particle Analyser).

The results table will contain the width and height of the smallest box
that encompasses each ear object. I use a similar technique in the CANAPI
algorithm (Chopping, M., (2011), CANAPI: Canopy Analysis with Panchromatic
Imagery, Remote Sensing Letters 2(1): 21-29, published 17 June 2010
http://dx.doi.org/10.1080/01431161.2010.486805).

  Best wishes,

   Mark

  Mark Chopping, Ph.D.
  Professor, Department of Earth & Environmental Studies
  Center for Environmental & Life Sciences LS 312
  Montclair State University, Montclair, NJ 07043 - It's All Here!
  NASA ABoVE, MISR, MODIS, & Terrestrial Ecology Science Teams
  ------------------------------------------------------------
  E: [hidden email] F: (973) 655-4072
  W: http://www.montclair.edu/csam/remote-sensing-lab/


> Date: Thu, 28 Jan 2016 08:29:53 -0800
> From: nhayden2 <[hidden email]>
> Reply-To: [hidden email]
> To: [hidden email]
> Subject: Multiple Object Length Measurement
>
> Hello Everyone,
>
> I am new to this forum and ImageJ. I am looking for some advice on how I
> could go about automatically measuring the length of multiple objects in one
> image. I am currently working on a project that requires me to get the
> lengths of multiple corn ears from one image.
>
> I have downloaded ObjectJ and been trying to use that but I am not familiar
> enough with either program to get my desired results.
>
> My current approach is using SIOX segmentation to get the corn ears
> separated from the background and using feret diameter to find the maximum
> length of each ear. I have not been able to get this to work like I want it
> to.
>
> Also, due to the large number of photos I would like to be able to automate
> this process if at all possible.
>
> If anyone has some info on where a good place for me to start would be, I
> would appreciate it.
>
> I am new to this program so if there are any good websites or articles that
> would help me to get familiar with it, I would appreciate some guidance.
>
> Thanks,
>
> Nicholas Hayden
>
>
>
>
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>
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