object-counting.m

path = 'coins.png';
image = imread(path);

figure, imshow(image), title('Original');

figure;
if size(image, 3) == 3
    gray = rgb2gray(image);
else
    gray = image;
end
subplot(1, 3, 1), imshow(gray), title('Grayscale');

adjusted = imadjust(gray);
subplot(1, 3, 2), imshow(adjusted), title('Adjusted');

filtered = medfilt2(adjusted, [7 7]);
subplot(1, 3, 3), imshow(filtered), title('Filtered');

canny = edge(filtered, 'canny');
figure, imshow(canny), title('Edges');

figure;

sc = strel('disk', 2);
closed = imclose(canny, sc);
subplot(1, 3, 1), imshow(closed), title('Closed Edges');

sd = strel('disk', 1);
dilated = imdilate(closed, sd);
subplot(1, 3, 2), imshow(dilated), title('Dilated Edges');

filled = imfill(dilated, 'holes');
subplot(1, 3, 3), imshow(filled), title('Filled Holes');

min_area = 512;
connected_comps = bwconncomp(filled);
stats = regionprops(filled, 'Area', 'BoundingBox');
large_regions = find([stats.Area] >= min_area);
fprintf("Object count: %d", size(large_regions, 2));

filtered_image = ismember(labelmatrix(connected_comps), large_regions);
figure, imshow(filtered_image), title('RegionProps');

figure;
imshow(image);
hold on;
for i = 1:length(large_regions)
    k = large_regions(i);
    rectangle('Position', stats(k).BoundingBox, 'EdgeColor', 'g', 'LineWidth', 1);
end
hold off;