| Re: How to detect edge of an image in IDL? [message #35621] |
Mon, 30 June 2003 06:26  |
David Fanning
Messages: 11724
Registered: August 2001
|
Senior Member |
|
|
TIAN Yunfeng writes:
> I wonder if there are routines doing edge detection in IDL. I look
> through the IDL Online Help, and only find two simple edge enhancement
> functions (sobel & roberts). I want to use Gauss-Laplacian or Canny
> edge operators to get binary edge images. Does someone have any ideas?
You can use the CONVOL function to implement Laplacian
edge detection in IDL. You can find a very simple
example of using Laplacian edge detection to sharpen
an image in this article:
http://www.dfanning.com/ip_tips/sharpen.html
I've never used a Canny filter in IDL, but I think
it could be created if you can't find someone who
has already done it. I suspect both the Gauss-Lbplacian
and the Canny filters are two step processes in which
a gaussian filter is applied, followed by the Laplacian.
You ought to be able to do both with the CONVOL function.
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
|
|
|
|
| Re: How to detect edge of an image in IDL? [message #35873 is a reply to message #35621] |
Fri, 25 July 2003 07:14  |
Johan Marais
Messages: 7
Registered: July 2003
|
Junior Member |
|
|
Are you stil looking for a way how dto do it?
Johan Marais
"David Fanning" <david@dfanning.com> wrote in message
news:MPG.1969e88c1ca66c54989694@news.frii.com...
> TIAN Yunfeng writes:
>
>> I wonder if there are routines doing edge detection in IDL. I look
>> through the IDL Online Help, and only find two simple edge enhancement
>> functions (sobel & roberts). I want to use Gauss-Laplacian or Canny
>> edge operators to get binary edge images. Does someone have any ideas?
>
> You can use the CONVOL function to implement Laplacian
> edge detection in IDL. You can find a very simple
> example of using Laplacian edge detection to sharpen
> an image in this article:
>
> http://www.dfanning.com/ip_tips/sharpen.html
>
> I've never used a Canny filter in IDL, but I think
> it could be created if you can't find someone who
> has already done it. I suspect both the Gauss-Lbplacian
> and the Canny filters are two step processes in which
> a gaussian filter is applied, followed by the Laplacian.
> You ought to be able to do both with the CONVOL function.
>
> 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
|
|
|
|
comp.lang.idl-pvwave archive
Members
Search
Help
Login
Home
