Abstract: Image rectification has important application to hydrographic surveying such as estimating the position of surveying instrument. A method for estimating the rectification homography of the sea surface is proposed based on the circular points on the surface plane. The method computes the image of absolute conic by different images of the porthole on survey ship. Two imaged circular points of sea surface are computed from the image of absolute conic and horizon. The rectified matrix is obtained from the singular value decomposition of the conic dual to circular points of sea surface. Experiments show that the angle measurement error in the rectified image is less than 1. 3°, which means the method is accurate and can be applied in various hydrographic applications.

Key words: hydrographic surveying, metric rectification, circular points

摘要： 在海洋测绘中，通过图像矫正的方法估算出测量仪器的位置具有非常重要的意义。针对海面目标位置估算中的图像透视矫正问题，提出一种基于平面虚圆点图像的海面图像度量矫正方法。利用不同角度下照片中圆形特征物的图像计算出绝对二次曲线的图像；根据绝对二次曲线以及图像中的海平线辨认海平面虚圆点的图像；通过对与海平面虚圆点对偶的二次曲线的图像进行奇异值分解，获得海平面图像的度量矫正矩阵。在图像实验中，平面上的角度矫正误差小于1.3°，表明这种方法具有较好的矫正精度，能够满足多种海洋测绘作业的要求。

关键词: 海洋测绘, 度量矫正, 虚圆点