The proposed image segmentation method mainly includes three stages: the first stage is using Otsu method to get the maximum variance of gray image between clusters

namely the optimal threshold. The second stage is gray image is segmented by the obtained threshold to generate achnatherum splendens and non achnatherum splendens binary image. The third stage is utilizing edge detection method combines mean filtering with mathematical morphological to extract achnatherum splendens image. and divide it with non achnatherum image.Based on unmanned aerial vehicle（UAV） image

use image segmentation method

achnatherum splendens can be extracted effectively.Results of estimation can obtain a higher accuracy of 97.3 % compared with measured achnatherum splendens coverage.