Fig. 1

a Set-up of leaf movement experiments for recognition by PALMA. 25 seedlings can be analyzed in parallel per vertical plate and each camera takes picture series of one plate. Red dots on the plates mark the boundaries of an individual chamber and of the entire plate. b Depicts a sample picture of the manual control step allowed by PALMA1. PALMA1 presents and overlay of the recognized chambers (in white) with the picture chosen for initial plant detection. Red squares indicate the borders of the detected chambers and of detected seedlings. In this example, PALMA1 recognized all chambers correctly but not all seedlings (e.g. seedling in the top left corner). c Plant detection by iterative contrasting. The first picture depicts a seedling as seen by camera before contrasting by PALMA1. Pictures two to four depict the same seedling in the first, fourth and eighth iterative contrasting step. d Depicts the final plant picture outlined and the detection of leaf tips by those pixels of the binarized seedling picture that cut across the outline (here marked by arrows)