Fig. 2: Examples of images of Arabidopsis collected in the field.

a Original images from the Swiss site (left column), and from the Japanese site (right column). Background (soil, sand, humus), surroundings (mesh around the plot, frames around the plot, or sheet on the ground), and the amount of noise (e.g., snow seen in the middle images from the Swiss site, strong light on the right half of the bottom images from the Japanese site) varied among images. Blue arrows indicate white marbles placed at the corners of the target area. b Close-up images representing the diversity in light conditions, in the background, and in the color, shape, and size of plants.