Fig 2. Flowchart outlining the steps of the algorithm.

First we acquire the images using a Leica AS LMD laser dissection microscope with a DFC 480 camera and then segment them using a local thresholding technique. Cells are detected using a distance transform of the segmented image and are then initially classified by their area. A number of subsequent steps then correctly classify cells into the four main regions; cortex, stele, endodermis and central metaxylem.