[R] Calculating diameters of cirkels in a picture.

Julian Burgos jmburgos at u.washington.edu
Thu Aug 23 22:55:16 CEST 2007

Hi Bart,

If you only have 36 circles, the fastest way would be to use some image 
processing software and measure the circles "by hand".  One option is to 
use ImageJ, which you can download here



Bart Joosen wrote:
> Hi,
> Maybe this is more a programming questions than a specific R-project question, but maybe there is someone who can point me in the right direction.
> I have a picture of cirkels which I took with a digital camera.
> Now I want to use the diameter of the cirkels on the picture for analysis in R.
> I can use pixmap to import the picture, but how do I find the outside cirkels and calculate the diameter?
> I pointed out that I can use the edci package, but then I need to preprocess the data to reduce the points, otherwise it takes a long time, and my computer crashes.
> If you want to see such a picture, I cropped a larger one, and highlighted the cirkel which is of interest.
> In a real world, this is a plate with 36 cirkels, which all should be measured.
> www.users.skynet.be/fa244930/fotos/outlined.jpg
> Thanks for your time
> Bart
> 	[[alternative HTML version deleted]]
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