“…Dock (Rumex obtusifolius L.) was detected in mixed grassland swards by recording images with a remote-controlled vehicle in the field, segmenting the images using a homogeneity threshold and defining objects and features by describing shape, colour and texture (Gebhardt & K€ uhbauch, 2007;Gebhardt, Schellberg, Lock, & K€ uhbauch, 2006). Bonesmo, Kaspersen, and Bakken (2004) developed an image processing system to estimate the canopy cover of white clover in a legume-grass mixture based on clover colour and morphological properties, and Fransen, de Boer, Terlou, During, and Dijkman (1998) used DIA to quantify the horizontal vegetation pattern in savanna grasslands. Based on results from a pot experiment, DIA was suggested as a method to assess the legume contribution in legume-grass mixtures (Himstedt, Fricke, & Wachendorf, 2009).…”