Creating edge detection kernel

4 views (last 30 days)
mona
mona on 10 Feb 2015
Commented: Image Analyst on 11 Feb 2015
I would appreciate if someone can briefly outline on how one can generate a 5x5 edge detection mask using an ideal step function: S(x,y)={(a for (xcosθ+ysinθ)<ρ AND a+h for (xcosθ+ysinθ)≥ρ)} which can be geometrically represented as follows:
I actually need to generate a mask so that I can apply it onto an image to detect edges. I would appreciate if someone can give me a detailed or high level idea.
Thank you,

Accepted Answer

Image Analyst
Image Analyst on 10 Feb 2015
Did you try a for loop over row and columns and use your formula:
for col = 1 : 5
for row = 1 : 5
rho = sqrt((row-2)^2+(col-2)^2);
theta = atand2(row/col);
and so on... Give it a try - it's not that hard. Remember x is column and y is row.
  3 Comments
mona
mona on 11 Feb 2015
I am mainly referring to page 21, section 9.2 in the following link: http://disp.ee.ntu.edu.tw/henry/edge_detection.pdf
Here, x matrix given in (55) is generated from equation (37).
Image Analyst
Image Analyst on 11 Feb 2015
Yes, you assign either a or a+h depending on if the center of the pixel is in the circle or shaded part.
His email is given in the paper and he said he had MATLAB code. Why don't you just ask him for the code?

Sign in to comment.

More Answers (0)

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!