Table 2.

Root image descriptors extracted by RIA-J.

Name	Description	Unit	Reference
MORPHOLOGY
area	Projected area of the root system	mm2	Galkovskyi et al., 2012
length	Length of the skeleton of the root system image	mm	Galkovskyi et al., 2012
tip_count	Number of end branches in the root system skeleton	–
diam_mean	Mean diameter of the root object in the image	mm
GEOMETRY
width	The maximal width of the root system	mm	–
depth	The maximal depth of the root system	mm	–
width_depth_ratio	Ratio between the width and the depth of the root system	–	Galkovskyi et al., 2012
com_x–com_y	Relative coordinates of the center of mass of the root system	–	Galkovskyi et al., 2012
convexhull	Area of the smallest convex shape encapsulating the root system	mm2	Galkovskyi et al., 2012
exploration	Ratio between the convex hull area and the projected area	–	Galkovskyi et al., 2012