Water bloom area extraction method based on mixed pixel correction

The invention provides a mixed pixel correction-based water bloom area extraction method, which comprises the following steps of: acquiring medium-low spatial resolution image data and high spatial resolution image data of a research area, and carrying out data preprocessing on images; calculating NDVI to obtain a grey-scale map, and performing threshold segmentation on the obtained grey-scale map by using a segmentation threshold to obtain a water bloom distribution binary image; according to the middle and low spatial resolution algal bloom distribution binary image, obtaining a middle and low spatial resolution cyanobacterial bloom pixel set; with reference to the high-spatial-resolution image water bloom distribution binary image of the corresponding spatial position, calculating a pixel water bloom area proportion in the blue-green algae water bloom pixel set with the middle and low spatial resolutions; for the pixel NDVI value and the water bloom area proportion in the blue algae water bloom pixel set w