Near are to a value

Hi, I was wondering if anyone knows how I can program the option for a binary image to which all its regions have been tagged to determine the index of that region whose area is closest to a value I enter, for expample 1.

value = 1;

Answer 1

[Image Analyst]

To extract the index of a desired number from a labeled (what you call "tagged") image, you can do this:

[labeledImage, numRegions] = bwlabel(allBlobs); % allBlobs is your binary image.
% Now extract blob #7 ONLY into a new binary image:
oneSingleBlob = ismember(labeledImage, 7);

[Alejandro Fernández]

But what I want is to extract the index from the region whose area is closest to 1 square pixel