Comments on: Dilation algorithms—Introduction http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithms-introduction/ 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. Wed, 01 Feb 2012 13:58:45 +0000 hourly 1 http://wordpress.org/?v=3.2.1 By: Steve Eddins http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithms-introduction/#comment-24757 Steve Eddins Thu, 22 Dec 2011 14:49:07 +0000 http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithmsintroduction/#comment-24757 Anton—Take a look at the 'ball' option of strel. Anton—Take a look at the ‘ball’ option of strel.

]]> By: Anton http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithms-introduction/#comment-24756 Anton Thu, 22 Dec 2011 14:32:40 +0000 http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithmsintroduction/#comment-24756 Hi Steve, how can i get dilation using element of hemispheric at selected scale.(sory for bad english) Hi Steve, how can i get dilation using element of
hemispheric at selected scale.(sory for bad english)

]]> By: Steve http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithms-introduction/#comment-23215 Steve Thu, 24 Jun 2010 15:30:29 +0000 http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithmsintroduction/#comment-23215 Danish—The Image Processing Toolbox supports morphology on arrays (rectlinear grids) only. You'll need to develop your own implementations for other geometries. Danish—The Image Processing Toolbox supports morphology on arrays (rectlinear grids) only. You’ll need to develop your own implementations for other geometries.

]]> By: Danish http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithms-introduction/#comment-23209 Danish Tue, 22 Jun 2010 06:16:41 +0000 http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithmsintroduction/#comment-23209 Hi Steve, How can we apply morphological operators (esp. Dilation) to 3D triangulated meshes similar to : http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.36.9118&rep=rep1&type=pdf Thanks Hi Steve,

How can we apply morphological operators (esp. Dilation) to 3D triangulated meshes similar to :
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.36.9118&rep=rep1&type=pdf

Thanks

]]> By: hira http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithms-introduction/#comment-22749 hira Mon, 22 Feb 2010 16:43:50 +0000 http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithmsintroduction/#comment-22749 thanks thanks

]]> By: Steve http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithms-introduction/#comment-22743 Steve Mon, 22 Feb 2010 13:33:35 +0000 http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithmsintroduction/#comment-22743 Hira—I don’t generally have time to consult on individual image analysis or algorithm development projects, or to help interpret research papers. I suggest that you take a look at the numerical pixel values at each step. Is the output of the dilation what you expect? And the output of the erosion? And then check the output of the elementwise division. If that is not what you expect, then it may be a data type or scaling issue. Check out the MATLAB documentation on the how arithmetic operators work on integer data types, and check out the Image Processing Toolbox documentation on the default dynamic ranges for different image types and data types. Finally, your formula dil(y)/ero(y) is missing any mention of structuring element, so you might want to review the paper again to try to determine what structuring element they are using. Hira—I don’t generally have time to consult on individual image analysis or algorithm development projects, or to help interpret research papers. I suggest that you take a look at the numerical pixel values at each step. Is the output of the dilation what you expect? And the output of the erosion? And then check the output of the elementwise division. If that is not what you expect, then it may be a data type or scaling issue. Check out the MATLAB documentation on the how arithmetic operators work on integer data types, and check out the Image Processing Toolbox documentation on the default dynamic ranges for different image types and data types. Finally, your formula dil(y)/ero(y) is missing any mention of structuring element, so you might want to review the paper again to try to determine what structuring element they are using.

]]> By: hira http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithms-introduction/#comment-22728 hira Thu, 18 Feb 2010 18:19:11 +0000 http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithmsintroduction/#comment-22728 hi actually i want to make a MapLum = dil(y)/ero(y) as doen in this paper "Face and Eyes Detection to Improve Natural Human-Computer Dialogue". for the MapLum will give high values around the eyes. i m trying to implement it but stucked in this MapLum as i m not getting the desired results as shown in the paper. after performing the dilation and erosion when i divide the images it gives me a totally black image. i dont know where is the problem. may be its the matter of the structuring element. please help me. kindly take a look of the paper and guide me how i could perform it.the link for the paper is: www.eurasip.org/Proceedings/Ext/ISCCSP2006/defevent/.../cr1070.pdf hi
actually i want to make a MapLum = dil(y)/ero(y) as doen in this paper “Face and Eyes Detection to Improve Natural Human-Computer Dialogue”.
for the MapLum will give high values around the eyes. i m trying to implement it but stucked in this MapLum as i m not getting the desired results as shown in the paper. after performing the dilation and erosion when i divide the images it gives me a totally black image. i dont know where is the problem. may be its the matter of the structuring element.
please help me. kindly take a look of the paper and guide me how i could perform it.the link for the paper is:

http://www.eurasip.org/Proceedings/Ext/ISCCSP2006/defevent/…/cr1070.pdf

]]> By: Steve http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithms-introduction/#comment-22709 Steve Tue, 16 Feb 2010 12:16:49 +0000 http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithmsintroduction/#comment-22709 Hira—The choice of structuring element depends on what effect you are trying to accomplish. You haven't said. For element-wise division use the </tt>./</tt> operator. Hira—The choice of structuring element depends on what effect you are trying to accomplish. You haven’t said. For element-wise division use the ./ operator.

]]> By: hira http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithms-introduction/#comment-22704 hira Mon, 15 Feb 2010 19:26:17 +0000 http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithmsintroduction/#comment-22704 what sort of structuring element should i use??? after applying dilation and erosion i have to divide both images "dy"(dilated image) and "ey"( eroded image). dy/ey gives error. please guide how to divide the images. regards what sort of structuring element should i use???

after applying dilation and erosion i have to divide both images “dy”(dilated image) and “ey”( eroded image). dy/ey gives error. please guide how to divide the images.
regards

]]> By: Steve http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithms-introduction/#comment-22701 Steve Sun, 14 Feb 2010 15:03:31 +0000 http://blogs.mathworks.com/steve/2008/09/03/dilation-algorithmsintroduction/#comment-22701 Hira—Use <tt>imdilate</tt> and <tt>imerode</tt>. Hira—Use imdilate and imerode.

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