GrabCut is an interactive segmentation method that extracts the foreground from the background in an image using the graph-theoretic max-flow/min-cut algorithm. Before the algorithm can start, the user first needs to provide some hint by specifying the foreground region in the input image roughly with minimum possible interaction (for example, by drawing a rectangle around the foreground region). The algorithm then segments the image iteratively to get the best possible result. In some cases, the segmentation may not be the desired one (for example, the algorithm may have marked some foreground region as background and vice versa).
In that case, the user needs to do fine touch-ups again by giving some strokes on the images ...
