Fig. 3

Stem detection procedure and calculation of stem width. a Side view segmented image based on plant exemplified in Fig. 1, b plant skeleton extracted from the segmented image, c extracted plant stem from the skeleton computed as the shortest path between the lowest and highest nodes on the skeleton (red line), d distance transform algorithm on segmented image (zoomed area shown in c) representing for each pixel of the image the distance to the nearest boundary pixel, e superimposed distance transform image to the stem extract from plant skeleton and f stem width along the stem, including the width at each leaf starting point