%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%Matching an image using naive exhaustive search%
%                                               %
%Hao Jiang, Oct 2007                            %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

im = imread('spider1.bmp');
im = im2double(im);
figure(1);
imshow(im);
% extracts the top-left and bottom-right corner of the template
[x,y] = ginput(2);
x = floor(x);
y = floor(y);
imb = zeros(max(y)-min(y)+1, max(x)-min(x)+1, 3);
imb(:,:,1) = im(min(y):max(y), min(x):max(x), 1);
imb(:,:,2) = im(min(y):max(y), min(x):max(x), 2);
imb(:,:,3) = im(min(y):max(y), min(x):max(x), 3);
im_template = imb;
[tph, tpw, tpd] = size(im_template);

pp = [x(1), y(1); x(1) + tpw - 1, y(1);...
      x(1) + tpw - 1, y(1) + tph - 1;...
      x(1), y(1) + tph - 1];

hold on;            
plot([pp(:,1); pp(1,1)], [pp(:,2); pp(1,2)], 'LineWidth', 3, 'Color', [1,0,0]);   
hold off;            

im_target = imread('spider2.bmp');
im_target = im2double(im_target);
figure(2);
imshow(im_target);
hold on;
tic
% Exhaustive search. pp is the bounding box of the match result.
pp = locate_imageblock(im_template, im_target);
toc

plot([pp(:,1); pp(1,1)], [pp(:,2); pp(1,2)], 'LineWidth', 3);   
hold off;