Hi. Anyone has an idea how to find the area at red region area?

[KSSV]

Attach the original image.

Answer 1

[Image Analyst]

%  Take the 3 largest blobs
mask = bwareafilt(mask, 3);
% Assume we want the middle one.  Label the blobs 1, 2, and 3.
[labeledImage, numBlobs] = bwlabel(mask);
% Extract the middle one, which has label 2:
middleBlob = ismember(labeledImage, 2);
imshow(middleBlob); % Display it.

[DGM]

to get the area

blobarea = bwarea(middleBlob)
% or 
blobarea = nnz(middleblob(:))

[Iszuzuldin amirull bin mohd janudin]

Thabk youu did it

[Image Analyst]

Thanks for adding that @DGM - I forgot that.

There is also a function bwarea() you can use. It weights the area according to the shape of the boundary locally so it gives a different area than summing the pixels or using nnz(). I don't usually use bwarea() though. I use nnz(). I've been told it's slightly faster than using sum().

Thanks for accepting the answer @Iszuzuldin amirull bin mohd janudin 🙂