Water surface area extraction method and device based on remote sensing image

Abstract

The invention provides a water surface area extraction method and device based on a remote sensing image. The method comprises the following steps: 1) for each pixel point in a satellite remote sensing NDWI image, taking the pixel point as a current pixel, and based on a difference value between a pixel gradient of the current pixel and a pixel gradient of a neighborhood pixel of the current pixel, calculating a gradient difference sum between the pixel gradient of the current pixel and the pixel gradient of the neighborhood pixel of the current pixel; 2) calculating the gradient complexity ofthe current pixel according to the sum of the gradient differences and the pixel gradient of the current pixel; 3) obtaining the average gradient complexity of the set of pixels with the same NDWI value as the current pixel; and 4) taking the NDWI value of which the average gradient complexity is greater than a preset threshold as a target NDWI value, and separating the water surface area in thesatellite remote sensing NDWI image by using a threshold method according to the target NDWI value. By applying the invention, the extraction efficiency of the water surface area is improved.

Description

technical field [0001] The invention relates to a remote sensing image-based water surface area extraction method, in particular to a remote sensing image-based water surface area extraction method. Background technique [0002] The development of aerospace technology and image recognition algorithms has promoted the progress of earth observation technology. At present, the observation of the earth's surface is usually based on the aerial images of satellites or aircrafts, and then the image interpretation is carried out to meet the demand for precise observation of the earth's surface. [0003] In the interpretation of aerial images or aerospace images, distinguishing between land and water areas in the images, and dynamically monitoring changes in water body area play an important role in guiding the development and utilization of water resources. At present, the existing interpretation technology usually uses NDWI (Normalized Difference Water Index, Normalized Difference ...

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Problems solved by technology

[0004] At present, most studies determine the NDWI extraction threshold of water body extraction through visual interpretation, which cannot realize automatic extraction of water body area remote sensing, resulting in low extraction efficiency of water surface area

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