| Re: ROI application... [message #32329] |
Wed, 02 October 2002 13:46 |
Dick Jackson
Messages: 347
Registered: August 1998
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Senior Member |
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"Richard Tyc" <richt@sbrc.ca> wrote in message
news:hjIm9.16622$0c5.3655@news2.mts.net...
> Application Question:
>
> Which tools, functions objects etc could be used to the following
image
> processing task:
>
> Highlight a region within an image with a solid color based on a
signal
> value range and then create a boundary line around this region (ROI).
We
> hope to use IDL to perform what an existing medical workstation does
for one
> specific task - highlight a region within a greyscale MRI image (eg. a
> tumour) to generate a boundary curve based on the relative intensity
of the
> pixels associated with the ROI.
> Lets say the tumor represented pixel intensity levels of 155-200. If
we set
> all pixels in this range to be red, we then need to generate a
boundary
> curve outlining this 'red' region.
>
> Could IDLgrROI and LABEL_REGION do this ?
For some great insight as to what IDLgrROIs can do, try out
IDL> XROI, /Test
Grab the pencil tool, draw an ROI in that 'flat' area of the image on
the far right, use right-mouse on the ROI edge you just drew, choose
Grow Region:By Threshold, and see if that's the kind of thing you're
looking for. (it uses the min/max of the area *you* drew and grabs any
neighboring pixels in that range) The boundary is done (as David
mentioned as a possibility) by a Contour command. You can find how they
did it in IDL's lib/utilities/XROI.pro, procedure xroi__GrowSelectedROI.
Even if you don't use Object Graphics, the IDLanROI class ("analysis"
class from which "graphics" class IDLgrROI inherits) is very useful for
working with ROIs.
Cheers,
--
-Dick
Dick Jackson / dick@d-jackson.com
D-Jackson Software Consulting / http://www.d-jackson.com
Calgary, Alberta, Canada / +1-403-242-7398 / Fax: 241-7392
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| Re: ROI application... [message #32332 is a reply to message #32329] |
Wed, 02 October 2002 13:11  |
David Fanning
Messages: 11724
Registered: August 2001
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Senior Member |
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Richard Tyc (richt@sbrc.ca) writes:
> Which tools, functions objects etc could be used to the following image
> processing task:
>
> Highlight a region within an image with a solid color based on a signal
> value range and then create a boundary line around this region (ROI). We
> hope to use IDL to perform what an existing medical workstation does for one
> specific task - highlight a region within a greyscale MRI image (eg. a
> tumour) to generate a boundary curve based on the relative intensity of the
> pixels associated with the ROI.
> Lets say the tumor represented pixel intensity levels of 155-200. If we set
> all pixels in this range to be red, we then need to generate a boundary
> curve outlining this 'red' region.
>
> Could IDLgrROI and LABEL_REGION do this ?
Probably, but it might be slow. If your region is
contiguous, and you want to have a boundary line
around it, then this Find_Boundary program on my
web page works nicely for me. (The Contour command
is another alternative.)
http://ftp.dfanning.com/pub/dfanning/outgoing/misc/find_boun dary.pro
Cheers,
David
--
David W. Fanning, Ph.D.
Fanning Software Consulting, Inc.
Phone: 970-221-0438, E-mail: david@dfanning.com
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Toll-Free IDL Book Orders: 1-888-461-0155
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