Output boundary coordinates of particles

[xin fang]

Hello,
I have a problem on particle analysis using ImageJ. I need to output the boundary coordinates of discrete particles (no overlap) on a 2D 8 or 16 bit gray scale image. The output format of boundaries needs to be clockwise or counterclockwise along the perimeter of each particle. I need the particle boundary output to construct a model for finite element modeling. Does any one know how to do that in ImageJ?
Many thanks,Xinding

     

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[Jeremy Adler]

About 20 years ago I wrote software to produce a sequential list of points around the perimeter object.
Part Part Syst Charact 12 ((1995) 28-37
 It was used to calculate fractal dimension, far better than box counting,  and a basis for  a very efficient way of obtaining the maximum feret diameter.

It be a very useful addition to imageJ


Jeremy Adler
[hidden email]
________________________________________
From: ImageJ Interest Group [[hidden email]] on behalf of xin fang [[hidden email]]
Sent: 09 February 2015 23:24
To: [hidden email]
Subject: Output boundary coordinates of particles

Hello,
I have a problem on particle analysis using ImageJ. I need to output the boundary coordinates of discrete particles (no overlap) on a 2D 8 or 16 bit gray scale image. The output format of boundaries needs to be clockwise or counterclockwise along the perimeter of each particle. I need the particle boundary output to construct a model for finite element modeling. Does any one know how to do that in ImageJ?
Many thanks,Xinding



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[Michael Schmid]

On Feb 9, 2015, at 23:24, xin fang wrote:
> Hello,
> I have a problem on particle analysis using ImageJ. I need to output the boundary coordinates of discrete particles (no overlap) on a 2D 8 or 16 bit gray scale image. The output format of boundaries needs to be clockwise or counterclockwise along the perimeter of each particle. I need the particle boundary output to construct a model for finite element modeling. Does any one know how to do that in ImageJ?
> Many thanks,Xinding

Hi Xinding,

that should be easy:

- Threshold the image

- Double click the Wand Tool and set the options to 4-connected or 8-connected, whatever you need.
  http://rsb.info.nih.gov/ij/docs/guide/146-Part-IV.html

- Click on the particle with the Wand tool

- Use the SelectionCoordinates ("List XY Coordinates") macro
  http://rsb.info.nih.gov/ij/macros/SelectionCoordinates.txt

You can modify the 'print' line of the macro as desired, e.g. omitting the first column 'i' or changing the separator characters to "," (comma) or "\t" (tab)

Michael

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