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Re: Image thresholding [message #15473 is a reply to message #15382]

Mon, 17 May 1999 00:00

Liam Gumley
Messages: 473
Registered: November 1994

Senior Member

David Brennan wrote:
> Does anyone know of a fast routine or function for searching through a
> 3D data set and setting numbers within a predetermined range of values
> to zero. i.e,
>
> the range is 5 - 10
>
> A data set contains [0,1,2,3,4,5,6,7,8,9]. It becomes
> [0,1,2,3,4,0,0,0,0,0]

With all due respect to my esteemed colleagues David Kastrup and David
Fanning, I believe the fastest method is as follows:

IDL> a = findgen(10)
IDL> print, ((a lt 5) or (a gt 10)) * a
0 1 2 3 4 0 0 0 0 0

Love those Boolean operators....

Cheers,
Liam.

---
Liam E. Gumley
Space Science and Engineering Center, UW-Madison
1225 W. Dayton St., Madison WI 53706, USA
Phone (608) 265-5358, Fax (608) 262-5974
http://cimss.ssec.wisc.edu/~gumley

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[Message index]

		Image thresholding By: Dave Brennan on Mon, 17 May 1999 00:00
		Re: Image thresholding By: Struan Gray on Tue, 18 May 1999 00:00
		Re: Image thresholding By: Brian Jackel on Mon, 17 May 1999 00:00
		Re: Image thresholding By: Liam Gumley on Mon, 17 May 1999 00:00
		Re: Image thresholding By: mgs on Mon, 17 May 1999 00:00
		Re: Image thresholding By: Liam Gumley on Mon, 17 May 1999 00:00
		Re: Image thresholding By: davidf on Mon, 17 May 1999 00:00
		Re: Image thresholding By: REV on Fri, 21 May 1999 00:00

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