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clear all; close all; clc;
image=imread('input_3.bmp');
[w,h] = size(image);
direct = zeros(w,h);
W = 16;
sum_value = 1;
bg_certainty = 0;
blockIndex = zeros(ceil(w/W),ceil(h/W));
times_value = 0;
minus_value = 0;
center = [];
filter_gradient = fspecial('sobel');
Gx = filter2(filter_gradient,0);
filter_gradient = transpose(filter_gradient);
Gy = filter2(filter_gradient,0);
g1=Gx.*Gy;
g2=(Gy-Gx).*(Gy+Gx);
g3 = (Gx.*Gx) + (Gy.*Gy);
for i=1:W:w
for j=1:W:h
if j+W-1 < h && i+W-1 < w
times_value = sum(sum(g1(i:i+W-1, j:j+W-1)));
minus_value = sum(sum(g2(i:i+W-1, j:j+W-1)));
sum_value = sum(sum(g3(i:i+W-1, j:j+W-1)));
if sum_value ~= 0 && times_value ~=0
bg_certainty = (times_value*times_value + minus_value*minus_value)/(W*W*sum_value);
if bg_certainty > 0.05
blockIndex(ceil(i/W),ceil(j/W)) = 1;
theta1 = pi/2+ atan2(2*times_value,minus_value)/2;
theta2=2*theta1;
Oy = sin(theta2);
Ox=cos(theta2);
f = fspecial('gaussian');
cos2theta = filter2(f,Ox);
sin2theta = filter2(f,Oy);
theta = atan2(sin2theta,cos2theta)/2;
center = [center;[round(i + (W-1)/2),round(j + (W-1)/2),theta]];
end;
end;
end;
end;
end;
figure;imagesc(direct);title('Orientation Field');
hold on
[u,v] = pol2cart(center(:,3),8);
quiver(center(:,2),center(:,1),u,v,0.3,'r');
colormap Gray;
hold off;
Index exceeds matrix dimensions.???
Error in ==> orientation_2 at 45
times_value = sum(sum(g1(i:i+W-1, j:j+W-1)));>
