基于自动阈值分类的高分辨率影像海陆分界线自动提取

海陆分界线的变化对滩涂面积和湿地系统变化具有指示作用并且影响航运活动,因而需提取海陆分界线.视海陆分界线为陆地(包括淤泥质潮滩)和海水(包括河道)的瞬时分界线.首先,构建近红外—绿—蓝波段的假彩色图像,进行色彩、对比度增强和双边滤波处理;其次,构建海陆分界线提取指数(Sea-land Boundary Extracti...

Automatic Extraction of The Sea-land Boundary from High Spatial Resolution Images based on Automatic Threshold Segmentation

The changes of sea-land boundary have indication effect on the changes of the intertidal areas and wetland system， and also influence sailing activities. The sea-land boundary is regarded as the transient boundary between land （including tidal flat） and sea （including rivers and ditches）. Firstly， pre-processing such as color and contract enhancement and bilateral filtering is applied on false color images combined with near-infrared， green and blue bands. Secondly， the Sea-land Boundary Extraction Index （SBEI） is constructed. Then， the automatic threshold analysis method is used to divide the images into ocean and continent， combining ocean areas on land by mistake with continent afterwards. In order to solve the problem of landward extending shoreline caused by the W width rivers， a specific erosion and dilation algorithm with the matrix of W+1 width is applied. Finally， the Canny edge detection operator is used to extract the boundary on images. To verify the effectiveness of this algorithm， GF-2 satellite images of three different areas with a resolution of one meter were used to conduct the experiments. The results show that the extraction accuracy by the proposed method is about 5 pixels， which is improved at least 10 pixels compared with NDWI and CV model.