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Re: Catch the area outside a contour [message #44099]

Sat, 21 May 2005 06:33

Chris Lee
Messages: 101
Registered: August 2003

Senior Member

James wrote:
> Hi Folks !
>
> Can anyone help me with the following problem. For example, there is an
> area
> of the image withing some contour level. How to determine and get
> parameters for a region otside that contour level withing the next N
> pixels ?
> Is there any IDL procedure/function for that ?
>
> Thanks in advance,
> James

You can get the X/Y coordinates of a contour levels with the PATH_INFO
keyword (and a few others). If you then want a fixed area outside this
you need to either

1. Use an IDL built in function (whose name I can't remember) which
'expands' an area by a fixed amount (then subtract the original)

or.

2. Draw the new path yourself. This would involve something like finding
the local normal at each point along the path. Calculate the path length
of the contour, expand along the the local normal to get the desired area.

Chris.

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[Message index]

		Re: Catch the area outside a contour By: Chris Lee on Sat, 21 May 2005 06:33
		Re: Catch the area outside a contour By: Adam[1] on Sat, 21 May 2005 00:36
		Re: Catch the area outside a contour By: James[1] on Fri, 20 May 2005 07:16
		Re: Catch the area outside a contour By: Adam[1] on Fri, 20 May 2005 07:08
		Re: Catch the area outside a contour By: James[1] on Mon, 23 May 2005 04:20

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