File:Images with different GSD.png

Example of drone images with different Ground Sampling Distance (GSD). a) aerial picture of a recollection point close to the beach, with bins and garbage bags. Different types of plastic bottles are distinguishable on the image with GSD = 0.5 cm/px (left). On the image with GSD = 1.25 cm/px (central), items can still be counted but not recognized, whereas it is difficult to count litter on the image with GSD = 1.85 cm/px (right); b) operational assessments of litter items marked on images. On the image with GSD = 0.5 cm/px (left), several items were detected, and their material and/or category can be recognized (black boxes). On the image with GSD = 1.25 cm/px (central), the smallest items could not be detected (red boxes), while only the four biggest items could be spotted on the image with GSD = 1.85 cm/px (right). Overall, in b), black boxes bound the detected items, whereas red boxes the missed items.