MATLAB: bwselect, url

blob = bwselect(bw);
imshow(blob);

the function displays bw and waits for you to click on the image with the mouse. You can click on one or multiple points. To finish your selection, double-click on the last point, or just press RETURN. bwselect then returns a binary image containing only the objects ("blobs") that you clicked on. You can also chose one position (10, 23) with:

blob = bwselect(bw, 10, 23);
clf % clear figure;
imshow(blob)

Read image from Internet link:

url = 'http://abc.com/images/us.png';
bw = imread(url);
imshow(bw)