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Re: tracking clusters through multiple timesteps [message #79349 is a reply to message #79255]

Mon, 20 February 2012 10:39

David Fanning
Messages: 11724
Registered: August 2001

Senior Member

Ian_Ashpole writes:

> For now i would like to work on an idealised case with no splitting or
> merging - but where the cloud will move quite a way from its start to
> finish location. I should specify that i am very much an IDL novice
> but it seems logical to pass the index given to a cluster of pixels
> (above a threshold of, say, 250, to filter out noise resulting from
> the initial flagging stage) at t to an overlapping cluster at t+1.

Yes, I can't tell you how to proceed because too many variables
come into play here, but to start with, I'd take a single cloud
in the first image and create a "movie" of that cloud moving
through space. If the cloud overlaps with *any* pixels in
the second image, then I would say those overlapping pixels belong
to the "cloud" in the second image. (Maybe if it overlaps more
than one cloud, you take the one that has more pixels? Both? Don't
know, you will have to decide.) Keep overlapping the last
cloud discovered with the next time image. Does the cloud
"move" and "change shape" in a reasonable way?

If it does, maybe you are on to something. If it doesn't,
well, the fish aren't going anywhere. ;-)

Now, you could do the second cloud, and add this
to your movie sequence, etc. Start with a handful
of the biggest clouds to see if this works. If they
were different colors, you could see the clouds
evolving in time as you played your movie.

I'm looking at clouds blowing around outside my window
right now. I seriously doubt whether this is going to
work very well. :-(

Cheers,

David

--
David Fanning, Ph.D.
Fanning Software Consulting, Inc.
Coyote's Guide to IDL Programming: http://www.idlcoyote.com/
Sepore ma de ni thui. ("Perhaps thou speakest truth.")

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[Message index]

		tracking clusters through multiple timesteps By: Ian[1] on Mon, 20 February 2012 09:34
		Re: tracking clusters through multiple timesteps By: manodeep@gmail.com on Mon, 20 February 2012 19:39
		Re: tracking clusters through multiple timesteps By: Ian[1] on Mon, 20 February 2012 15:08
		Re: tracking clusters through multiple timesteps By: cgguido on Mon, 20 February 2012 11:35
		Re: tracking clusters through multiple timesteps By: David Fanning on Mon, 20 February 2012 10:39

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