%Function:Simple?Edge?Detection
%Data:3rd?Oct.2008

clc;
clear?all;
close?all;

%%%%%%%%%%%%%%%%
%%%??Imread??%%%
%%%%%%%%%%%%%%%%
I0=imread（‘picturename.jpg‘）;
I=rgb2gray（I0）;
J0=double（I）;
J_x=J0;
J_y=J0;
J=J0;
[MN]=size（I）;

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%??Sobel?Operator?Filtering??%%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
Sobel_x=（1/4）*[-1-2-1;000;121];
Sobel_y=（1/4）*[-101;-202;-101];
[W_SW_S]=size（Sobel_x）;
Half_W_S=（W_S-1）/2;
%Filtering?with?Matrix?Sobel_x?to?Get?gx
for?p=Half_W_S+1:M-Half_W_S???
????for?q=Half_W_S+1:N-Half_W_S
????????filter_sum=0;
????????for?k=-Half_W_S:Half_W_S
????????????for?l=-Half_W_S:Half_W_S
????????????????filter_sum=filter_sum+J0（p+kq+l）*Sobel_x（k+Half_W_S+1l+Half_W_S+1）;
????????????end
????????end
????????J_x（pq）=filter_sum;
????end
end
%Filtering?with?Matrix?Sobel_y?to?Get?gy
for?p=Half_W_S+1:M-Half_W_S
????for?q=Half_W_S+1:N-Half_W_S
????????filter_sum=0;
????????for?k=-Half_W_S:Half_W_S
????????????for?l=-Half