Largest rectangle inscribed inside multiple blobs

Hi,

I have few blobs where I need to fit the largest area rectangle inside. I used the matlab function LargestRectangle to find the rectangle and it works well for a single blob.

a = imread('blob.png');

LRout=LargestRectangle(a);

But how to get rectangles for multiple blobs in the same image?

I have gone through regionprops. What I understood is, I need to seperate each blob and then calculate the highest rectangle for each one as I can't use LargestRectangle with regionprops. Now my question is how to separate each blob so that I can get the largest rectangle for each one?

Answer 1

[Simon Chan]

How about separate them into 6 different images and put into the function?

The images are stored in BW(:,:,1) to BW(:,:,6).

A = imread('Matlab output of blob seq.png');
[L,n]=bwlabel(A);
tiledlayout(2,3)
for k=1:n
	nexttile
	BW(:,:,k)=(L==k);
	imshow(BW(:,:,k));
end

[Sunetra Banerjee]

Hi,

Thanks a lot. That's a great idea. But 'tiledlayout' is not working in my R2019a. If I want to use subplot instead of 'tiledlayout', how to use this?

[Simon Chan]

Use this:

A = imread('Matlab output of blob seq.png');
[L,n]=bwlabel(A);
for k=1:n
	BW(:,:,k)=(L==k);
	subplot(2,3,k)
	imshow(BW(:,:,k));
end

[Sunetra Banerjee]

Hi,

Now it's working fine. Thanks a lot for your help.