I made a few improvements. This seems to work fine:
clc; % Clear the command window.
close all; % Close all figures (except those of imtool.)
clear; % Erase all existing variables. Or clearvars if you want.
workspace; % Make sure the workspace panel is showing.
format short g;
format compact;
fontSize = 15;
fprintf('Beginning to run %s.m ...\n', mfilename);
grayImage = imread('cameraman.tif');
subplot(2, 1, 1);
imshow(grayImage);
edg = edgy(grayImage);
subplot(2, 1, 2);
imshow(edg, []);
fprintf('Done running %s.m.\n', mfilename);
function edg = edgy(originalImage)
[rows, columns, numberOfColorChannels] = size(originalImage);
% Convert to gray scale if necessary
if numberOfColorChannels == 3
originalImage = rgb2gray(originalImage);
end
C = double(originalImage);
Gx = zeros(rows, columns);
Gy = zeros(rows, columns);
for row = 1 : rows - 2
for col = 1 : columns - 2
%Sobel mask for x-direction:
Gx=((2*C(row+2,col+1)+C(row+2,col)+C(row+2,col+2))-(2*C(row,col+1)+C(row,col)+C(row,col+2)));
%Sobel mask for y-direction:
Gy=((2*C(row+1,col+2)+C(row,col+2)+C(row+2,col+2))-(2*C(row+1,col)+C(row,col)+C(row+2,col)));
%The gradient of the image
%B(i,j)=abs(Gx)+abs(Gy);
C(row,col)=sqrt(Gx.^2+Gy.^2);
end
end
edg = C;
end
