# How to identify boundaries of shapes in an image using the change in color

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Yash on 27 Apr 2013
Commented: ankita taparia on 11 Dec 2018
Hi I am new to Matlab, I have got to identify boundaries of irregular shapes in Image using the change in color, Please guide me how to get info from image into a matrix

Image Analyst on 28 Apr 2013
If you want the color edges, then the most sensible thing is to measure Delta E - the color difference - between a pixel and its neighbors. I just gave the algorithm a few days ago here: http://www.mathworks.com/matlabcentral/answers/73635#answer_83593 An edge will have a high delta E while non-edges will have low delta E. I now have a demo script of this. Let me know if you want me to post it.

Image Analyst on 7 Dec 2018
You might try a filter, like
or a mean shift filter, or a Kuwahara filter.
ankita taparia on 11 Dec 2018
Mean shift filter is not giving satisfactory result. And DEM code is giving errors which I am not able to fix. Please help.
ankita taparia on 11 Dec 2018
Also, I tried Sobel filter and getting decent results with it..only if i could be suggested one or two ilters like sobel(not canny) so that i could compare and proceed further.

Ahmed A. Selman on 27 Apr 2013
There are few files in the file-exchange http://www.mathworks.com/matlabcentral/fileexchange/ so do some search there, you might find what you need.
Or, you can convert the colored image to binary one, then use the function (edge).

Yash on 27 Apr 2013
I have searched but couldn't find useful sol
Ahmed A. Selman on 27 Apr 2013

Yash on 2 May 2013
Thanks for the script, I think this will definitely be helpful to me. I need to construct a geometry through this So I need to get the Coordinates of the boundaries created in the image as well as the colour code to know about the orientation. Please help me how can I convert the output that I have got to a matrix containing the required information.
Regards yash

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