3D-Modelling of seafloor structures from ROV-based video sequences

在水下成像和水下三维重建中，尽管水下壳体的玻璃界面会发生折射，但大多数研究者仍然使用透视相机模型[SK11]。很容易看出，单视点相机模型（SVP模型）由于折射效应是无效的。尽管人们已经知道这一点有一段时间了，但没有一个结构-运动系统（SfM系统）明确地模拟折射效应。因此，本项目的总体目标是评估折射成像的使用，并将其与经典透视SfM方法进行比较。前期研究和我们第一阶段项目的结果已经表明，在重建水下图像序列的相机路径时，使用透视相机模型引起的系统模型误差会导致姿态估计误差[SK11]。我们期望正确的折射成像物理建模将导致相机模型的改进，从而消除透视三维建模中的系统误差。由此产生的三维模型可以用于改进海底结构的体积测量。

In underwater imaging and underwater 3D reconstruction, most researchers still use the perspective camera model, even though refraction at the glass interface of the underwater housing occurs [SK11]. It can easily be shown, that the single-view-point camera model (SVP model) is invalid due to refractive effects. Even though this has been known for a while, no Structure-from-Motion system (SfM system) explicitly models refraction effects. Therefore, the overall goal of this project is to evaluate the use of refractive image formation and to compare it to the classical perspective SfM approaches. Preliminary studies and our results of the first project phase already indicated that the systematic model error caused by using the perspective camera model leads to a pose estimation error, when reconstructing the camera path of an underwater image sequence [SK11]. We expect that the correct physical modeling of refractive image formation will lead to improved camera models that will eliminate the systematic errors in perspective 3D modeling. The resulting 3D models can then be used for improved volumetric measurements of seafloor structures.