Connected Component Labeling
<p>In OpenCV 3.0 there is a function called <a href="http://docs.opencv.org/3.0.0/d3/dc0/group__imgproc__shape.html#gac2718a64ade63475425558aa669a943a" rel="nofollow noreferrer">connectedComponent</a>. </p>

<p>I know that it takes as input a binary image and returns the labels and the number of connected components, but what algorithm is used internally?</p>