中文摘要：

平坦的海岸带淤泥质潮滩水边线是模糊的水陆边界，在遥感图像上呈现复杂的边缘，特征获得连续、准确的水边线轮廓是水边线自动提取过程中的难点之一。以长江口崇明东滩为例，选取两景有代表性的Landsat TM影像，采用灰度形态学方法对图像进行预处理，然后采用小波模极大值法获取不同尺度下的水边线轮廓，解决了高细节区边缘的破碎问题，实现了淤泥质海岸带潮滩模糊边界的水边线自动提取。

英文摘要：

Waterline of muddy tidal flats in coastal zone is a kind of blur boundary between a water body and an exposed land mass, which takes on a complex image edge in a remote sensing image. Acquisition of continuous and precise waterline contour is one of the most difficult things for the automatic extraction of waterline from Landsat TM or other satellite data. Taking the Chongming Dongtan in the Yangtze estuary as an example, this paper first processed the Landsat TM images based on gray morphology theory, then acquired the waterline of tidal flats at different scales by means of wavelet transform modulus maxima. With two images of different tidal conditions the methods effectively solved the problems of discontinuous waterline edges and many loose edge points existing in high detail areas, and then achieved the automatic extraction of blur waterline in the muddy tidal flat.