3D-Surface Reconstruction

P5的重点是从可用图像数据估计密集和高分辨率的3D重建。 为此，我们采取了两个阶段的策略：（1）基于机载立体相机，我们的目标是计算一个粗糙的半密集视觉SLAM（深度图，几何和相机运动）。 它是在四旋翼上以视频帧速率计算的，并考虑了3D位置和图像信息的统计不确定性。(2)在地面站上，我们通过考虑来自主传感器的高分辨率图像，将半密集3D重建改进为高分辨率密集3D重建。更具体地说，我们计划生成密集的深度图，然后将其融合到密集的3D模型中。此步骤还将考虑光束法平差的3D点云和激光扫描仪的3D点云。 在项目的第二阶段，我们将强调通过反射对扰动的鲁棒性，这种两阶段策略的主要优点是，我们将以不依赖于与地面站的通信的方式对机载计算的场景进行基本的自定位和半密集3D重建。例如，密集3D重建可以用于自适应视点规划：在飞行期间，系统可以立即识别哪些位置尚未获得足够的视觉信息。 这些信息又可用于调整飞行轨迹，以确保对未知区域进行最佳探索。

The focus of P5 is the estimation of dense and high-resolution 3D reconstruction from the available image data. To this end, we pursue a two-stage strategy:(1) Based on the onboard stereo camera, we aim at computing a crude semi-dense visual SLAM (depth maps, geometry and camera motion). It is computed at video frame rate on the quadrotor and takes into account the statistical uncertainty of 3D locations and image information.(2) On the ground station, we improve the semi-dense 3D reconstruction toward a high-resolution dense 3D reconstruction by also taking into account the high-resolution images from the main sensor. More specifically we plan to generate dense depth maps which are then fused to a dense 3D model. This step will also take into account 3D point clouds from bundle adjustment and 3D point clouds from the laser scanner. In this second phase of the project, we will emphasize robustness to perturbations through reflections, homogeneous surfaces and over-exposure.A central advantage of this two-stage strategy is that we will have a rudimentary self-localization and semi-dense 3D reconstruction of the scene computed onboard in a manner that does not depend on the communication with the ground station.The resulting semi-dense 3D reconstruction can for example be used for an adaptive viewpoint planning: During the flight, the system can immediately identify for which locations it has not obtained sufficient visual information yet. This information can in turn be used to adapt the flight trajectory so as to assure an optimal exploration of unknown territory.