Image Edge Detection using Sobel Operator

1 view (last 30 days)
Osama Ahmed
Osama Ahmed on 13 Oct 2020
Commented: Osama Ahmed on 2 Nov 2020
I am working on an assignment where I have to detect image edge using Sobel operator. It was stated that the output image must be uint8 format and has two fewer rows and columns than the input one, since the pixels in first and last columns and rows do not have enough neughbors for the required computation. I am struggling in the last part as I get same input and ouput size. I would apperciate your help and suggestions. I have attached my code for your reference.
function [edge] = edgy(cc)
cc = double(cc);
H = size(cc,1);
W = size(cc,2);
edge = cc;
sx = [-1 0 1;-2 0 2;-1 0 1];
sy = [1 2 1;0 0 0;-1 -2 -1];
for i = 2 : H-1
for j = 2 : W-1
A = cc(i - 1 : i + 1, j - 1 : j + 1);
a = (sum(sx .* A));
x = sum(a);
b = (sum(sy .* A));
y = sum(b);
pixValue =sqrt(x.^2+ y.^2);
edge(i, j) = pixValue;
end
end
edge = uint8(edge);
end
  2 Comments
João Pedro de Freitas Coelho
function edge = edgy(figure)
cc = double(figure);
sx = [-1 0 1; -2 0 2; -1 0 1];
sy = [1 2 1; 0 0 0; -1 -2 -1];
B = cc;
for ii = 2:(size(B,1)-1)
for jj = 2:(size(B,2)-1)
A = cc((ii-1):(ii+1),(jj-1):(jj+1));
x = sx.*A;
x = sum(sum(x));
y = sy.*A;
y = sum(sum(y));
pixValue = uint8(sqrt(x.^2 + y.^2));
B(ii,jj) = pixValue;
end
end
B = uint8(B);
edge = B(2:end-1,2:end-1);
end

Sign in to comment.

Answers (0)

Community Treasure Hunt

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

Start Hunting!