Comments on: Seen on the web: MATLAB example for tracing and measuring skin lesions http://blogs.mathworks.com/steve/2006/07/14/seen-on-the-web-matlab-example-for-tracing-and-measuring-skin-lesions/ 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/2006/07/14/seen-on-the-web-matlab-example-for-tracing-and-measuring-skin-lesions/#comment-22407 Steve Fri, 04 Dec 2009 18:43:24 +0000 http://blogs.mathworks.com/steve/?p=70#comment-22407 Andrea—You can use the 'Image' and 'ConvexImage' properties returned by regionprops. You can use a logical operation to find the object pixels in "concave" regions. Then maybe you can look at the ratio of the number of pixels in concave regions to the total number of object pixels. Andrea—You can use the ‘Image’ and ‘ConvexImage’ properties returned by regionprops. You can use a logical operation to find the object pixels in “concave” regions. Then maybe you can look at the ratio of the number of pixels in concave regions to the total number of object pixels.

]]> By: Andrea http://blogs.mathworks.com/steve/2006/07/14/seen-on-the-web-matlab-example-for-tracing-and-measuring-skin-lesions/#comment-22379 Andrea Wed, 25 Nov 2009 10:08:49 +0000 http://blogs.mathworks.com/steve/?p=70#comment-22379 Nice presentation of how to trace the skin lesions. I have a similar problem. In my case I try to trace the boundaries of different nuclei. I have to major cases: isolated nuclei and overlapping nuclei. I managed to get a black and white image and my question now is how to distinguish when there is a single nuclei or two overlapping nuclei. One idea is that a single nuclei is a convex area and two overlapping nuclei is a concave area. Is there any method that can tell me if a given labelled object is convex or concave? Due to irregularities, also for the single nuclei, some parts of the contour might look concave. Br, Andrea Nice presentation of how to trace the skin lesions. I have a
similar problem. In my case I try to trace the boundaries of
different nuclei.

I have to major cases: isolated nuclei and overlapping nuclei. I managed to get a black and white image and my question now is how to distinguish when there is a single nuclei or two overlapping nuclei. One idea is that a single nuclei is a convex area and two overlapping nuclei is a concave area. Is there any method that can tell me if a given labelled object is convex or concave? Due to irregularities, also for the single nuclei, some parts of the contour might look concave.

Br,
Andrea

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