“…As shown in Table 1 , there are two approaches for detecting or segmenting a leaf from the background: based on image segmentation techniques [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ], and based on machine learning techniques [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ]. In the first approach, image processing techniques such as color thresholding, superpixel (SLIC), GrabCut [ 27 ], watershed, and random walker [ 28 ] are commonly employed.…”