Comments on: Quick tip: Determining uniqueness of local maximum http://blogs.mathworks.com/steve/2006/04/10/quick-tip-determining-uniqueness-of-neighborhood-maximum/ Steve Eddins manages the Image & Geospatial development team at The MathWorks and coauthored Digital Image Processing Using MATLAB. He writes here about image processing concepts, algorithm implementations, and MATLAB. Sat, 11 Feb 2012 18:27:50 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Steve http://blogs.mathworks.com/steve/2006/04/10/quick-tip-determining-uniqueness-of-neighborhood-maximum/#comment-22901 Steve Tue, 23 Mar 2010 21:47:22 +0000 http://blogs.mathworks.com/steve/?p=52#comment-22901 Vr—Try this: <pre class="code"> [r,c] = find(I == max(I(:))); </pre> Vr—Try this:

[r,c] = find(I == max(I(:)));
]]> By: Vr http://blogs.mathworks.com/steve/2006/04/10/quick-tip-determining-uniqueness-of-neighborhood-maximum/#comment-22896 Vr Tue, 23 Mar 2010 04:13:47 +0000 http://blogs.mathworks.com/steve/?p=52#comment-22896 I have an image 128*128.. which has a pixel with max intensity 233. How can i find the coordinates of the pixel..? I have an image 128*128.. which has a pixel with max intensity 233. How can i find the coordinates of the pixel..?

]]> By: Gerti http://blogs.mathworks.com/steve/2006/04/10/quick-tip-determining-uniqueness-of-neighborhood-maximum/#comment-22635 Gerti Fri, 22 Jan 2010 00:58:31 +0000 http://blogs.mathworks.com/steve/?p=52#comment-22635 This is in reference to one of Amir's earlier question, if I understood the question correctly. I found the max(x,y) of a given matrix A by using this method: [max_val, x_max] = max(max(A)); %gives the column coordinate [max_val, y_max] = max(max(A')); %notice the transpose. gives the row coordinate I know that the same value will be written twice on max_val, but this is another way of obtaining (x_max, y_max) coordinates. This is in reference to one of Amir’s earlier question, if I understood the question correctly. I found the max(x,y) of a given matrix A by using this method:

[max_val, x_max] = max(max(A)); %gives the column coordinate
[max_val, y_max] = max(max(A’)); %notice the transpose. gives the row coordinate

I know that the same value will be written twice on max_val, but this is another way of obtaining (x_max, y_max) coordinates.

]]> By: warith http://blogs.mathworks.com/steve/2006/04/10/quick-tip-determining-uniqueness-of-neighborhood-maximum/#comment-21747 warith Sat, 09 May 2009 20:21:35 +0000 http://blogs.mathworks.com/steve/?p=52#comment-21747 sorry for the previous question I did not read the help carefully. Thank you sorry for the previous question I did not read the help carefully.

Thank you

]]> By: warith http://blogs.mathworks.com/steve/2006/04/10/quick-tip-determining-uniqueness-of-neighborhood-maximum/#comment-21746 warith Sat, 09 May 2009 20:19:27 +0000 http://blogs.mathworks.com/steve/?p=52#comment-21746 Hi there, I have a 3D matrix and I want to find the local extrema of it. I mean the coordinates of points that are bigger/smaller than its 26 neighboors. Can anybody help me ? Thanks in advance ! Hi there,

I have a 3D matrix and I want to find the local extrema of it. I mean the coordinates of points that are bigger/smaller than its 26 neighboors.

Can anybody help me ?

Thanks in advance !

]]> By: Kevin http://blogs.mathworks.com/steve/2006/04/10/quick-tip-determining-uniqueness-of-neighborhood-maximum/#comment-21542 Kevin Wed, 04 Mar 2009 13:26:13 +0000 http://blogs.mathworks.com/steve/?p=52#comment-21542 Thank for your advice, Steve. It's really informative. Thank for your advice, Steve. It’s really informative.

]]> By: Steve http://blogs.mathworks.com/steve/2006/04/10/quick-tip-determining-uniqueness-of-neighborhood-maximum/#comment-21538 Steve Wed, 04 Mar 2009 12:24:41 +0000 http://blogs.mathworks.com/steve/?p=52#comment-21538 Kevin—As you suggest, just use both <tt>imregionalmax</tt> and <tt>imregionalmin</tt>. Kevin—As you suggest, just use both imregionalmax and imregionalmin.

]]> By: Kevin http://blogs.mathworks.com/steve/2006/04/10/quick-tip-determining-uniqueness-of-neighborhood-maximum/#comment-21534 Kevin Wed, 04 Mar 2009 02:53:14 +0000 http://blogs.mathworks.com/steve/?p=52#comment-21534 Hi Steve, I meant <a href="http://en.wikipedia.org/wiki/Maxima_and_minima" rel="nofollow">'maxima and minima'</a>. I need to search out both of them. The fact that I can apply 'imregionalmax' and 'imregionalmin', then union 2 sets. But it's great if there is any function that can do both of them probably :-). Thank you for the quick reply. Kevin Hi Steve,
I meant ‘maxima and minima’. I need to search out both of them.
The fact that I can apply ‘imregionalmax’ and ‘imregionalmin’, then union 2 sets. But it’s great if there is any function that can do both of them probably :-).
Thank you for the quick reply.
Kevin

]]> By: Steve http://blogs.mathworks.com/steve/2006/04/10/quick-tip-determining-uniqueness-of-neighborhood-maximum/#comment-21533 Steve Tue, 03 Mar 2009 15:19:52 +0000 http://blogs.mathworks.com/steve/?p=52#comment-21533 Kevin—What is your definition of "extrema" in this context? Kevin—What is your definition of “extrema” in this context?

]]> By: Kevin http://blogs.mathworks.com/steve/2006/04/10/quick-tip-determining-uniqueness-of-neighborhood-maximum/#comment-21532 Kevin Tue, 03 Mar 2009 15:17:29 +0000 http://blogs.mathworks.com/steve/?p=52#comment-21532 Hi Steve, The tutorial's clear and absolutely useful. Thanks a lot. I have a minor question, Steve. I wonder if there is any function finding extrema in stead of maxima as 'imregionalmax'. Regards. Kevin. Hi Steve,
The tutorial’s clear and absolutely useful. Thanks a lot.
I have a minor question, Steve. I wonder if there is any function finding extrema in stead of maxima as ‘imregionalmax’.

Regards.
Kevin.

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