Applying Blob Detection Technique to the Original Image

clc;

clear all;

originalImage = imread('coins.png');

subplot(3, 3, 1);

imshow(originalImage);

% Maximize the figure window.

set(gcf, 'Position', get(0, 'ScreenSize'));

[pixelCount grayLevels] = imhist(originalImage);

subplot(3, 3, 2);

bar(pixelCount); title('Histogram of original image');

xlim([0 grayLevels(end)]); % Scale x axis manually.

thresholdValue = 100;

binaryImage = originalImage > thresholdValue;

binaryImage = imfill(binaryImage, 'holes');

% Display the binary image.

subplot(3, 3, 3); imagesc(binaryImage); colormap(gray(256)); title('Binary Image, obtained by thresholding'); axis square;

labeledImage = bwlabel(binaryImage, 8); 

coloredLabels = label2rgb (labeledImage, 'hsv', 'k', 'shuffle');

subplot(3, 3, 4);              imshow(labeledImage, []);          

title('Labeled Image, from bwlabel()');

axis square;      subplot(3, 3, 5);                                

imagesc(coloredLabels);

axis square;

caption = sprintf('Pseudo colored labels, from label2rgb().\nBlobs are numbered from top to bottom, then from left to right.');

title(caption);

blobMeasurements = regionprops(labeledImage, originalImage, 'all');  

numberOfBlobs = size(blobMeasurements, 1);

subplot(3, 3, 6); imagesc(originalImage);

title('Outlines, from bwboundaries()'); axis square;       hold on;

boundaries = bwboundaries(binaryImage);      

numberOfBoundaries = size(boundaries);

for k = 1 : numberOfBoundaries

              thisBoundary = boundaries{k};

              plot(thisBoundary(:,2), thisBoundary(:,1), 'g', 'LineWidth', 2);

end

hold off;