A coastline intelligent extraction method and system based on environmental parameter adaptation

Abstract

The present application provides a kind of based on environmental parameter adaptive coastline intelligent extraction method and system, method includes: obtaining the remote sensing image data of target area of the coastline to be extracted and its imaging phase tidal level data, and the remote sensing image data is preprocessed;Based on the remote sensing image data after preprocessing, the SSC of target area is calculated by inversion, and the corresponding adaptive water index graph of target area is dynamically selected by water index;Adaptive water index graph is threshold segmented, and preliminary water mask graph is obtained;According to tidal level data, the tidal period of imaging phase is judged, and based on tidal period, preliminary water mask graph is dynamically selected by morphological operation and boundary optimization is carried out, and the water mask graph after optimization is obtained;From the water mask graph after optimization, coastline is extracted and postprocessed, and the final target area coastline is obtained;The present application can realize the high-precision, high-robustness coastline automatic extraction under the complex nearshore dynamic change environment.

Claims

1. A method for intelligent extraction of coastlines based on adaptive environmental parameters, characterized in that, It includes the following steps: S1: Obtain the remote sensing image data of the target area where the coastline is to be extracted and the tidal water level data at the imaging time, and preprocess the remote sensing image data; S2: Invert and calculate the suspended sediment concentration SSC of the target area based on the preprocessed remote sensing image data, dynamically select a water body index according to the suspended sediment concentration SSC, and calculate the corresponding adaptive water body index map of the target area; Among them, dynamically selecting a water body index according to the suspended sediment concentration SSC includes: When SSC ≤ the first preset threshold, select the NDWI water body index; When the first preset threshold < SSC ≤ the second preset threshold, select the MNDWI water body index; When SSC > the second preset threshold, select a fused water body index, where the fused water body index is a linear weighted fusion of the IWI water body index and the NDWI water body index; S3: Perform threshold segmentation on the adaptive water body index map to obtain a preliminary water body mask map; S4: According to the tidal water level data, judge the tidal period at the imaging time, and dynamically select a morphological operation based on the tidal period to optimize the boundary of the preliminary water body mask map to obtain an optimized water body mask map; Among them, when the tidal water level is greater than the third preset threshold, it is determined as the high tide period, and closing operation is used for boundary optimization; When the tidal water level is less than or equal to the third preset threshold, it is determined as the low tide period, and opening operation is used for boundary optimization; The closing operation uses a diamond-shaped structuring element for boundary optimization, and the opening operation uses a square structuring element for boundary optimization; S5: Extract the coastline from the optimized water body mask map and perform post-processing to obtain the final coastline of the target area.

2. The intelligent coastline extraction method based on adaptive environmental parameters according to claim 1, characterized in that, In step S1, the remote sensing image data is specifically multispectral remote sensing image data, and the spectral bands include the blue light band, the green light band, the red light band, the near-infrared band, and the short-wave infrared band; The preprocessing includes any one or more of radiometric calibration, atmospheric correction, geometric precise correction, and cloud masking.

3. The intelligent coastline extraction method based on adaptive environmental parameters according to claim 1, characterized in that, In step S2, the suspended sediment concentration SSC of the target area is calculated based on the water color remote sensing inversion model, expressed as: in, The remote sensing reflectance is obtained from the preprocessed remote sensing image data; and These are the red and green wavelengths corresponding to the preprocessed remote sensing image data, respectively. , and These are the first to third empirical parameters, respectively.

4. The intelligent coastline extraction method based on adaptive environmental parameters according to claim 1, characterized in that, In step S3, the Otsu threshold segmentation algorithm is used to perform binary segmentation of water body and non-water body on the adaptive water body index map to obtain a preliminary water body mask map.

5. The intelligent coastline extraction method based on adaptive environmental parameters according to claim 1, characterized in that, In step S5, the optimized water body mask map is converted into a vector polygon layer, and the edge detection algorithm is used to extract the water body boundary line in the vector polygon layer as the preliminary coastline; Perform post-processing on the preliminary coastline to obtain the final coastline of the target area.

6. The intelligent coastline extraction method based on adaptive environmental parameters according to claim 1, characterized in that, In step S5, the post-processing includes: speckle removal, smoothing processing based on the B-spline curve fitting algorithm, topological anomaly inspection, and topological repair.

7. A coastline intelligent extraction system based on adaptive environmental parameters, employing the method described in any one of claims 1 to 6, characterized in that, It includes: Data acquisition module: used to obtain the remote sensing image data of the target area where the coastline is to be extracted and the tidal water level data at the imaging time, and preprocess the remote sensing image data; Water index calculation module: used to invert and calculate the suspended sediment concentration (SSC) of the target area based on the preprocessed remote sensing image data, and dynamically select the water index according to the suspended sediment concentration (SSC) to calculate the adaptive water index map corresponding to the target area. Preliminary segmentation module: used to perform threshold segmentation on the adaptive water index map to obtain a preliminary water mask map; Boundary optimization module: used to determine the tidal period of the imaging phase based on the tidal water level data, and to perform boundary optimization on the preliminary water body mask map based on the dynamic selection of morphological operations according to the tidal period, so as to obtain the optimized water body mask map; Coastline extraction module: used to extract the coastline from the optimized water mask map and perform post-processing to obtain the final target area coastline.

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