Analysis of image sequence. (1) Images need to be taken. (2) Centre of each black bead must be selected. (3) The template size around the black bead has to be chosen. (4) The maximum search length of the template must be given. (5) In each image the positions of the five black beads are automatically tracked. (6) The area of the polygon defined by the positions of the 5 black beads is computed for each image. (7) Relative growth rate is calculated from the increase in area. (For a detailed step by step guide on Martrack Leaf consult the manual (see Additional file 1).