grayImage = imread('coins.png');
subplot(2,2,1);
imshow(grayImage);
binaryImage = grayImage > 100;
binaryImage = imfill(binaryImage, 'holes');
[labeledImage, numObjects] = bwlabel(binaryImage);
stats = regionprops(labeledImage,'Area');
allAreas = [stats.Area]
[~, indexOfLargest] = max(allAreas);
largestBlob = ismember(labeledImage, indexOfLargest)>0;
subplot(2,2,2);
imshow(largestBlob);
title('Largest');
keeperIndexes = 1:numObjects;
keeperIndexes(indexOfLargest) = [];
binaryImage2 = ismember(labeledImage, keeperIndexes)>0;
subplot(2,2,3);
imshow(binaryImage2);
title('All Except Largest');