Edge Detection in Matlab

komathi86
Member • Dec 6, 2008

Edge Detection in Matlab

Hi, I'm doing a project on transforming photographs into cartoons using matlab. I'm stuck at the edge detection stage. Is there any way I can combine the 5 different types of edge detection methods -Sobel, Prewitt, Roberts, Gaussian and Canny to obtain an efficient edge detection??? Please help. Thank you very much

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silverscorpion

Member • Dec 6, 2008

Edge detection is nothing but a filtering process. There are so many types of filters like sobel or canny filters available. You can also use your own algo to create your own customized filters to do the edge detection. But I dont think you can combine all the filters into one 'efficient' filter. The type of filter to be used depends on the application and the efficiency too depends on various factors like type of filter and the value of threshold, etc. So instead of trying to combine many filters, you can try using all the filters one by one and determine which one works best for the application you have at hand..

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komathi86

Member • Dec 6, 2008

Thank you very much for your reply. It is very helpful. I have tried the different filters separately n feel that Canny works best. However, I will try to come up with an customized one and see how it works too. Thank you very much 😀

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rahulrajpl

Member • Feb 4, 2009

Hi,
I am also starting a project whose first phase is the edge detection. And I am learning edge detection using matlab
Just entered into this forum. Hope it will be useful.

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komathi86

Member • Feb 6, 2009

Hi rahul,

Thx for the reply. I have combined the various edge detection methods available in Matlab. However, there are too many unnecessary details (cheek lines,forehead lines etc) in the sketch obtained. Do you have any idea how to only extract the essential lines(eyes, nose, lips and face outline)? Thank you

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Ashraf HZ

Member • Feb 6, 2009

Maybe you can try some threshold techniques, komathi. That'll remove minor details somewhat.

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silverscorpion

Member • Feb 6, 2009

convolute your image with this matrix:

[ 0 0 0 0 0
0 1 1 1 0
0 1 1 1 0
0 1 1 1 0
0 0 0 0 0]

This will reduce the total number of connected components in the image. Then do edge detection with sobel or some other filter. I guess this will reduce the unwanted lines. U might still want to use some other thresholding techniques as well..

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rahulrajpl

Member • Mar 4, 2009

I have done with the edge detection using available filters and I find canny useful. next step i need is to find the no. of objects in the image. ? I mean object as component in the image bounded by 1 only shall be considered as one object and I need to perform some actions on these objects separately. Is there any functions for that?

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jiya ali

Member • Mar 7, 2009

<removed>
my project is biometric(fingerprint) based file encryption... my Question i have done edge detection by using MATLAB edge function but now i want to plot detected edges in graph ... but dont know how it will be done.... plz help me

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Predictor

Member • Mar 14, 2009

komathi86
Hi, I'm doing a project on transforming photographs into cartoons using matlab. I'm stuck at the edge detection stage. Is there any way I can combine the 5 different types of edge detection methods -Sobel, Prewitt, Roberts, Gaussian and Canny to obtain an efficient edge detection???
There are a number of ways to fuse edge detectors (such as taking an average, maximum, etc.), but unless you have some well-defined measure of the quality of the combined edge detector, I don't know how much better you can expect performance to get.

For what it's worth, I've had some success using Phillips' differential edge detector, which can be implemented to execute fairly quickly in MATLAB (see: "Image Processing, Part 6: Advanced Edge Detection", by Dwayne Phillips, "C/C++ Users Journal", Jan-1992).

-Will Dwinnell
<a href="https://matlabdatamining.blogspot.com/" target="_blank" rel="nofollow noopener noreferrer">Data Mining in MATLAB</a>

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digitalpbk

Member • Apr 29, 2009

Text on Digital Image Processing By Gonzalez would give some information on this topic.
Edge Thinning algorithms and image thinning...

<a href="https://edge.kitiyo.com/" target="_blank" rel="nofollow noopener noreferrer">the Sobel Edge detector using FPGA Project</a>

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gaurav5242

Member • Oct 12, 2009

hii everyone.....

i am new to this forum...

i am working on a project in which i have to detect cracks on the pcb through edge detection.....
how should i start...???

thanks......

😕

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Predictor

Member • Feb 17, 2010

gaurav5242
i am working on a project in which i have to detect cracks on the pcb through edge detection.....
how should i start...???
You will need a basic plan (what tools will be used, how performance will be measured, etc.) and you will need to obtain example images to train on. These images will need to be labeled somehow as "crack" / "not cracked" or graded some how (25% cracked, etc.).

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thechamp

Member • Feb 19, 2010

i have a matlab query too

i have a hardware ( say microcontroller) whose one port is connected to pc and other to a device (say robot or micromouse). the program to run the device is uploaded in my hardware. when i execute this, hardware sends signal to device. but i want to read those signals using MATLAB that are being sent to device. DAQ toolbox can help me, yet i dont know how. or any other way to accomplish it?

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itika_ece

Member • Mar 31, 2011

Hi,
I am also starting the project on edge detection in Matlab.Firstly i want to find the edges i.e.(connectivity of white pixels) in matrix. so kindly help me out .
thanks

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Gigi

Member • Sep 17, 2011

Hi, I am doing my mini project now on 'Edge Detection of Fundus Images',using Canny Edge Detector (instead of using inbuilt function, 'for -loop' should be used). can u please help me for the sorce code for this as 'm-file'.
Thank u.

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simplycoder

Member • Sep 17, 2011

@#-Link-Snipped-##-Link-Snipped-# :

Please read the 2nd sticky from the top.
Please show your work, then only members would help you.
As of now, I don't see a reason why the members including me would like to help you, as you haven't even posted your work.

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