Aiming at the problems that the target ships are always near the sea-sky line and often appear discontinuous clutter and isolated noise points on the sea in video image

a method is put forward that combines edge detection with threshold segmentation and Hoff line detection to detect the sea-sky line. Remove sea-sky line and above background

positioning the target ships accurately. Then the local adaptive threshold segmentation is used to remove the discontinuity clutter because of vortex on the sea

and the real target ships are segmented.Finally

in order to fill the cavities of the middle of the target ships and remove the rest points to eliminate the influence on target points

the morphological procession and the connected domain area detection is used.Experimental results show that the method can effectively remove the interference of sea clutter and noise

and can effectively detect the target ships under the background of sea.