MATLAB: How to display the two biggest blobs in terms of area

blobdisplayfilter by areaImage Processing Toolbox

I have a binary image 'i' which I have attached here. From this image, I want to find the two biggest blobs in terms of area. When I tried this code, I am able to find the biggest blob which I have attached and the next biggest blob is removed.
labeledImage=bwlabel(i);
measurements=regionprops(labeledImage,'Area');
allAreas=[measurements.Area];
[biggestArea, indexOfBiggest]=sort(allAreas,'descend')
biggestBlob=ismember(labeledImage,indexOfBiggest(1));
biggestBlob=biggestBlob>0;
figure,imshow(biggestBlob,[]);
I tried to use the bwareafilt() but MATLAB R2013a does not support it. Kindly help me to display the next biggest blob.
Thanking you.

Best Answer

In the line 
biggestBlob=ismember(labeledImage,indexOfBiggest(1));
you are finding the biggest by looking at the first index in a sorted array. So to get the second biggest you do 
secondBlob=ismember(labeledImage,indexOfBiggest(2));
Then you can combine them simply by doing 
twoBiggest = biggestBlob | secondBlob;
This is because both blobs are binary - 1s and 0s - so by doing an OR operation it makes every white part in both images seen in both images.
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