The invention belongs to the technical field of remote-sensing
image processing and application and relates to a method for detecting a million-
ton large-scale ship target in a high-resolution multispectral
remote sensing image. The method comprises the following steps: firstly, gradient-based
image segmentation is carried out on an image; secondly, geometrical characteristic and color characteristic of the segmentation object are extracted; and thirdly, by the utilization of a large-scale ship characteristic prior
knowledge base, the segmentation object is classified by a
fuzzy rule so as to obtain a large-scale ship object. In addition, as for detection of a large-scale ship in the port area, sea and land segmentation is carried out by the utilization of sea and land boundary information in a port prior
knowledge base so as to remove the influence of the land part at a port. By adding a postprocessing step, error results detected at a non-million-
ton berth are eliminated by the utilization of berth information in the port prior
knowledge base. By full utilization of rich spectral information and
high resolution of the high-resolution multispectral
remote sensing image and by the use of the prior knowledge base, high reliability of detection results is guaranteed, and manual intervention is little during the detection process.