Figure 2
From: Imaging local soil kinematics during the first days of maize root growth in sand
Steps of the image processing for the segmentation of the root system body from the greyscale image of the root-soil specimen. A 3D variance filter is applied to the original greyscale image, the output is segmented and each connected pixel is labelled. The frequency distribution of the new labelled image presents two main peaks corresponding to the background (B) and the root system (R). The segmentation is carried out in 3D, but a 2D cross section is displayed here for the sake of readability.
