Can anyone explain the loops in this code?

figure(2)

file1='Frame_0001.png';%Reference

I=imread(file1);

imshow(I)

J=rgb2gray(I);

K=imresize(J, [500 500]); 

figure(3)

file2='Frame_0242.png';

P=imread(file2);

imshow(P)

Q=rgb2gray(P);

R=imresize(Q,[500 500]);

bbox1=edge(K,'canny');

bbox2=edge(R,'canny');

matched_data1=0;

matched_data2=0;

white_points=0;

black_points=0;

for a=1:1:500

      for b=1:1:500

          if (bbox1(a,b)==1)

              white_points=white_points+1;

          else
              black_points=black_points+1;
          end
      end
  end

for i=1:1:500

      for j=1:1:500

          if (bbox2(i,j)==1)

              matched_data1=matched_data1+1;

          else

              matched_data2=matched_data2+1;

          end

      end

end

total_data=white_points;

matched_data=matched_data1;

traffic_density_percentage=abs((((matched_data-total_data)/total_data)*100)*6.5);

figure(4)

if (traffic_density_percentage>=0) && (traffic_density_percentage<15)

      instruc = 'Zero Traffic, Green Light for 15 seconds';

      display=insertObjectAnnotation(R, 'rectangle', [0 450 0  0], instruc);

      imshow(display);

elseif (traffic_density_percentage>=15) && (traffic_density_percentage<32)

      instruc = 'Low Traffic, Green Light for 40 seconds';

      display=insertObjectAnnotation(R, 'rectangle', [0 450 0  0], instruc);

      imshow(display);

elseif (traffic_density_percentage>=32) && (traffic_density_percentage<70)

      instruc = 'Moderate Traffic, Green Light for 60 seconds';

     display=insertObjectAnnotation(R, 'rectangle', [0 450 0  0], instruc);

     imshow(display);

else (traffic_density_percentage >=70)

      instruc = 'Heavy Traffic, Green Light for 90 seconds';

      display=insertObjectAnnotation(R, 'rectangle', [0 450 0  0], instruc);

      imshow(display);

end

print('first','-dpng','-r300');

Answer 1

[sloppydisk]

They're counting the number of white points, black points and matched data, but they could be replaced by using logical indexing, (for example for the first one):

white_points = sum(bbox1);
black_points = sum(~bbox1);