Comments on: Corresponding labeled objects in two images http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/ 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. Fri, 10 Feb 2012 18:55:59 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Steve http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-24477 Steve Wed, 14 Sep 2011 12:48:52 +0000 http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-24477 Image Vision—Regarding question 1, I assume that the two images are somehow different, even though they have the same number of objects. How are they different? Is each object in one image guaranteed to overlap with only one object in the other image? Regarding question 2, that's what this post is about. Did you find the techniques described here to be helpful? If not, what's missing? Image Vision—Regarding question 1, I assume that the two images are somehow different, even though they have the same number of objects. How are they different? Is each object in one image guaranteed to overlap with only one object in the other image? Regarding question 2, that’s what this post is about. Did you find the techniques described here to be helpful? If not, what’s missing?

]]> By: Image vision http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-24421 Image vision Wed, 17 Aug 2011 12:55:58 +0000 http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-24421 Hi, Thanks for your post. Please guide in the following: Please consider some other example! 1) If in image2 objects are numbered differently than that of image1. how i can relabel as that of image1. Here the number of objects found are same in both images. 2) in another case: If in image2, the numbers of objects are more than that of image1 how i can pick up objects in image2 that corresponds to image1 with labeling as that of image1 and discarding extra objects in image2. best regards, Image Vision. Hi,
Thanks for your post.
Please guide in the following:
Please consider some other example!
1)
If in image2 objects are numbered differently than that of image1.
how i can relabel as that of image1. Here the number of objects found are same in both images.

2) in another case:
If in image2, the numbers of objects are more than that of image1
how i can pick up objects in image2 that corresponds to image1 with labeling as that of image1 and discarding extra objects in image2.
best regards,
Image Vision.

]]> By: Steve http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-24307 Steve Tue, 05 Jul 2011 20:20:28 +0000 http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-24307 Satish—That's more or less what this post is about. Did you find the techniques described here to be helpful? If not, what's missing? Satish—That’s more or less what this post is about. Did you find the techniques described here to be helpful? If not, what’s missing?

]]> By: sathish http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-24293 sathish Wed, 29 Jun 2011 14:40:36 +0000 http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-24293 hi steve, I have similar images with circular/partially circular objects in them. The object number is not conserved and the same object in one image is not necessarily circular in the other. I would like to compare the objects with the same label in both images. Is there anyway to track the object and give it the same label as in the other image? To simply say it, I want to preserve the label of the object from one image to other. I tried using regionprops with centroid. I m wondering if there is better way to do it. Thanks for the posts. I closely follow them when I m in doubt. sathish. hi steve,

I have similar images with circular/partially circular objects in them. The object number is not conserved and the same object in one image is not necessarily circular in the other.
I would like to compare the objects with the same label in both images. Is there anyway to track the object and give it the same label as in the other image? To simply say it, I want to preserve the label of the object from one image to other.
I tried using regionprops with centroid. I m wondering if there is better way to do it.

Thanks for the posts. I closely follow them when I m in doubt.

sathish.

]]> By: Steve http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-22077 Steve Mon, 31 Aug 2009 12:16:53 +0000 http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-22077 Michael—If these labeled objects came from <tt>bwlabel</tt> or <tt>bwconncomp</tt>, then they are already apart. You can use <tt>imerode</tt> on the whole image at once to shrink all the objects further. If the labeled objects are actually touching, can you say more about how you computed them? Michael—If these labeled objects came from bwlabel or bwconncomp, then they are already apart. You can use imerode on the whole image at once to shrink all the objects further. If the labeled objects are actually touching, can you say more about how you computed them?

]]> By: Michael Habib http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-22065 Michael Habib Tue, 18 Aug 2009 11:46:16 +0000 http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-22065 Hi, Is there a way to 'imeorde' merged labeled objects to set them apart. I found that 'imerode', and 'imdilate' treat the labeled image as a binary image. I know I can do it through a loop, but it gives poor performance, as I have tens of thousands of objects. thanks Michael Hi,
Is there a way to ‘imeorde’ merged labeled objects to set them apart. I found that ‘imerode’, and ‘imdilate’ treat the labeled image as a binary image. I know I can do it through a loop, but it gives poor performance, as I have tens of thousands of objects.

thanks

Michael

]]> By: Steve http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-21632 Steve Thu, 02 Apr 2009 17:17:49 +0000 http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-21632 Shoeb—There's nothing in the Image Processing Toolbox that will do that for you automatically. You'll have to do some algorithm development on your own. I'd start my searches with something like "object tracking" and "blob analysis." Shoeb—There’s nothing in the Image Processing Toolbox that will do that for you automatically. You’ll have to do some algorithm development on your own. I’d start my searches with something like “object tracking” and “blob analysis.”

]]> By: Shoeb http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-21600 Shoeb Mon, 23 Mar 2009 20:07:07 +0000 http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-21600 Great post Steve! I have one question. Is it possible to do the same thing with labeled objects that moves in the next image? For example, I have series of images where my region of interest is slowly moving with time. Sometimes one breaks into 2 and sometimes 2 merge into one. Other times that moves slowly from its starting point. Is there any way to identify a particular object in all the images? Thanks in advance! Great post Steve! I have one question. Is it possible to do the same thing with labeled objects that moves in the next image?

For example, I have series of images where my region of interest is slowly moving with time. Sometimes one breaks into 2 and sometimes 2 merge into one. Other times that moves slowly from its starting point. Is there any way to identify a particular object in all the images?

Thanks in advance!

]]> By: Steve http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-20646 Steve Tue, 22 Apr 2008 16:31:12 +0000 http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-20646 Brett—Thanks. Brett—Thanks.

]]> By: Brett Shoelson http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-20645 Brett Shoelson Tue, 22 Apr 2008 15:23:55 +0000 http://blogs.mathworks.com/steve/2008/04/21/corresponding-labels/#comment-20645 Nice post, Steve. In fact, very nice series on labeling. For completeness on this entry, I thought I'd point out that if you don't specifically need the visual of the adjacency graph, you can easily get the same information (which image 1 objects were relabeled 6 in image 2?) directly from the calculation of pairs: >> pairs(pairs(:,2)==6) ans = 9 10 Also, one might not always be looking for how objects relabeled in image 2 correspond to original labels in image 1. Sometimes one might want to know how an object labeled 9 in image 1, for instance, was relabeled in image 2: >> find(S(9,:)) ans = 6 Or: >> pairs(pairs(:,1)==9,2) ans = 6 Nice post, Steve. In fact, very nice series on labeling.

For completeness on this entry, I thought I’d point out that if you don’t specifically need the visual of the adjacency graph, you can easily get the same information (which image 1 objects were relabeled 6 in image 2?) directly from the calculation of pairs:

>> pairs(pairs(:,2)==6)
ans =
9
10

Also, one might not always be looking for how objects relabeled in image 2 correspond to original labels in image 1. Sometimes one might want to know how an object labeled 9 in image 1, for instance, was relabeled in image 2:

>> find(S(9,:))
ans =
6

Or:

>> pairs(pairs(:,1)==9,2)
ans =
6

]]>