中文摘要：

水下地形的测量对研究河流运动与泥沙冲淤具有重要的实际意义。应用B超仪可以采集到水下地形的实时图像,该文据此提出了一种基于B超图像的水下地形边界提取与重建的方法。该方法利用地形的连续性以及B超图像中地形亮带灰度和梯度的变化特征,实现了图像中地形边界线的提取与重建,适应性较好。然后通过曲线拟合和样条插值,重新构建了水下三维地形。研究结果表明：重建后的三维地形与实际水下地形吻合较好,直观可视,再现了水下地形原貌。

英文摘要：

Underwater topography measurement is vital for the research of river channel movement and sedimentation scour.Faced with the collected images by using B-mode ultrasound device, this paper describes a new method of extracting and reconstructing underwater topographic lines based on B-mode ultrasound imaging technique. The continuity of topography under the water and its spatial distribution of grayscale and gradient in the ultrasonic images are used to realize the extraction and reconstruction of topographic lines. This method has a good adaptability and 3D underwater topography is reconstructed after curve fitting and spline interpolation. Results show the reconstructed 3D topography matches the actual underwater topography surface very well and the original topography under the water can be reappeared with visualization.