Sum of rectangles in Matlab - matlab

Question

I have a code which doesnt work the way I want to. The problem is i need a sum of all rctangles from a picture as below.
My code:
imH = size(I, 1);
imW = size(I, 2);
windowWidth = 30;
windowHeight = 30;
step = 1;
for r = 1:step:imH - windowHeight + 1
for c = 1:step:imW - windowWidth + 1
Win = I(r:r + windowHeight - 1, c:c + windowWidth - 1, :);
post =[c r windowHeight windowWidth];
I think I lack sum here
%stop = waitforbuttonpress;
subplot(121); imshow(I); title 'Image';
hold on;
rectangle('Position', pos, 'EdgeColor', 'r');
hold off;
subplot (122); imshow(W); title 'ooo';
drawnow;
pause(0.0000001);
end
end
Everything works great but I need to sum separately every rectangle values

Answer 1

You only need to add & in the 1st and 2nd rgb intervals as below:
matchNh = (R > 45 & R < 180) & (G > 50 & G < 185) & (B > 160 & B < 215);
matchNd = (R > 40 & R < 115) & (G > 6 & G < 80) & (B > 10 & B < 75);
Then you are doing right to count the nonzero pixels i.e.
Nh = nnz(matchNh);
Nd = nnz(matchNd);
If you want to use for more than one image , then you can use another for loop outside the two for loops e.g.
imgnames = dir('*.jpg'); % get list of jpg images in current directory
NN = length(imgnames)
%sliding window size
windowWidth = 64;
windowHeight = 64;
%step
step = 64;
Nh = 0;
Nd = 0;
for ii = 1 : NN
I = imread(imgnames(ii).name);
% your code i.e. two for loops as you have written above
imH = size(I, 1);
imW = size(I, 2);
for r = 1:step:imH - windowHeight + 1
for c = 1:step:imW - windowWidth + 1
%sliding window value
W = I(r:r + windowHeight - 1, c:c + windowWidth - 1, :);
pos =[c r windowHeight windowWidth];
R = W(:,:,1);
G = W(:,:,2);
B = W(:,:,3);
% RGB intervals for every sliding window
matchNh = (R > 45 & R < 180) & ...
(G > 50 & G < 185) & ...
(B > 160 & B < 215);
matchNd = (R > 40 & R < 115) & ...
(G > 6 & G < 80) & ...
(B > 10 & B < 75);
Nh = Nh + nnz(matchNh);
Nd = Nd + nnz(matchNd);
end
end
PIc = Nd / (Nh + Nd)
end