What is the best edge detector?

Hello What is the difference between sobel, prewitt, canny, laplacien, log...What is the best one used to detect edges? I used sobel and log edge detector but always i had an open edges. There is some solution to close edges? thanks

[Walter Roberson]

If someone asks you what the best vehicle is for bringing home milk, are you going to tell them a particular brand and model and model year of automobile before even asking whether the milk is being transported a block from the corner store, or hundreds of miles up to the International Space Station ?

There is no "best" algorithm to detect edges. There are algorithms that are better in particular circumstances. Better algorithms yet might be invented a week from Sunday, or within a few billion years at latest.

[Pamela Paolo]

thanks

Answer 1

[Image Analyst]

The best edge detector is the one that you are happiest with.

For edge linking or closing gaps in edge outlines, try imclose() or try Peter's site for edge-linking code: http://www.csse.uwa.edu.au/~pk/Research/MatlabFns/#edgelink

[Pamela Paolo]

thanks

[Pamela Paolo]

Hi I used the edge linking but i had this error. Can you correct it please

??? Error using ==> feval
Undefined function or method 'junction' for input arguments of type 'logical'.

Error in ==> makelut at 54
        lut(k) = feval(fun, a, params{:});

Error in ==> findendsjunctions at 14
    lut = makelut(@junction, 3);

Error in ==> edgelink at 16
    [RJ, CJ, re, ce] = findendsjunctions(EDGEIM);

[Image Analyst]

junction() is not in the current folder or on the path. Find it then add its folder to the path with addpath().

[Pamela Paolo]

this function doesn't exist. I couldn't find it.

[Walter Roberson]

It is part of findendsjunctions.m and is the first routine in that file after findendsjunctions itself.

[Image Analyst]

I haven't used that edge linking code. It's Peter's. If you've searched your hard drive for both those m-files, and can't find any of them, and you've searched inside all the m-files and still couldn't find it, then you'll have to contact Peter.