How to modify this code to upload an image manually and match the image from stored database

w=load_database();

try  
ri=round(2*rand(1,1));             % Randomly pick an index.
k=w(:,ri);                          % k contains the image we later on will use to test the algorithm
v=w(:,[1:ri-1 ri+1:end]);           % v contains the rest of the 1 images.

N=20;                               % Number of signatures used for each image.
%% Subtracting the mean from v
O=uint8(ones(1,size(v,2))); 
m=uint8(mean(v,2));                 % m is the maen of all images.
vzm=v-uint8(single(m)*single(O));   % vzm is v with the mean removed. 

%% Calculating eignevectors of the correlation matrix
% We are picking N of the 10 eigenfaces.
L=single(vzm)'*single(vzm);
[V,D]=eig(L);
V=single(vzm)*V;
V=V(:,end:-1:end-(N-1));            % Pick the eignevectors corresponding to the 10 largest eigenvalues. 

%% Calculating the signature for each image
cv=zeros(size(v,2),N);
for i=1:size(v,2);
    cv(i,:)=single(vzm(:,i))'*V;    % Each row in cv is the signature for one image.
end

%% Recognition 
%  Now, we run the algorithm and see if we can correctly recognize the face. 
axes(handles.axes10);
%title('Looking for ...','FontWeight','bold','Fontsize',16,'color','red');

axes(handles.axes3);
p=k-m;                              % Subtract the mean
s=single(p)'*V;
z=[];
for i=1:size(v,2)
    z=[z,norm(cv(i,:)-s,2)];
    if(rem(i,20)==0),imshow(reshape(v(:,i),112,92),'Parent',handles.axes3),end;
    drawnow;
end

[a,i]=min(z);
axes(handles.axes3);
imshow(reshape(v(:,i),112,92),'Parent',handles.axes3);title('Found!','FontWeight','bold','Fontsize',16,'color','red');

catch
    image = imread('no.jpg');
    axes(handles.axes3);
    imshow(image,'Parent',handles.axes3);title('Cannot Find!','FontWeight','bold','Fontsize',16,'color','red');
end

Answer 1

[Image Analyst]

To upload an image, use copyfile().

To match, it depends on how exactly the two images must match.

[LAI Mom Cin]

Above the code is random pick the image from the stored databas. If I'm using GUI (filename=gui.m&gui.fig) to click button for upload the image and detect the face recognition as below example. How can I match (click button "SCAN") the face detection in the database image and come out with a "Found!" result.

[Image Analyst]

See the Face Recognition app by Brett Shoelson of the Mathworks: Face Recognition