The idea of the hypothetical Magellanica Continent(Terra Australis Incognita)was introduced into China by the Jesuit missionaries during the seventeenth century.While not accepted by the Chinese government,it was affi...The idea of the hypothetical Magellanica Continent(Terra Australis Incognita)was introduced into China by the Jesuit missionaries during the seventeenth century.While not accepted by the Chinese government,it was affirmed and transmitted to the public by a few Chinese scholars,including Feng Yingjing,Cheng Bai'er,Zhang Huang,Xiong Mingyu,Xiong Renlin,You Yi,Zhou Yuqi,Jie Xuan,Wang Honghan,and Ye Zipei.Most of them communicated closely with the Jesuit missionaries,and several even helped the missionaries compose the maps.The concept was updated progressively by Matteo Ricci,Giulio Aleni,Johann Adam Schall von Bell,Francesco Sambiasi,and Ferdinand Verbiest.Chinese scholars copied the missionaries'relevant maps and textual introductions without much modification.However,they paid little attention to advancements in the idea,and many of them circulated outdated knowledge.It was not until the middle-and late-nineteenth century that Chinese scholars reexamined the correctness of this hypothetical continent.展开更多
为提高ORB-SLAM2 (oriented fast and rotated brief, and simultaneous localization and mapping)系统的位姿估计精度并解决仅能生成稀疏地图的问题,提出了融合迭代最近点拟合(iterative closest point, ICP)算法与曼哈顿世界假说的...为提高ORB-SLAM2 (oriented fast and rotated brief, and simultaneous localization and mapping)系统的位姿估计精度并解决仅能生成稀疏地图的问题,提出了融合迭代最近点拟合(iterative closest point, ICP)算法与曼哈顿世界假说的位姿估计策略并在系统中加入稠密建图线程。首先通过ORB(oriented fast and rotated brief)特征点法、最小显著性差异(least-significant difference, LSD)算法和聚集层次聚类(agglomerative hierarchical clustering, AHC)方法提取点、线、面特征,其中点、线特征与上一帧匹配,面特征在全局地图匹配。然后采用基于surfel的稠密建图策略将图像划分为非平面与平面区域,非平面采用ICP算法计算位姿,平面则通过面与面的正交关系确定曼哈顿世界从而使用不同估计策略,其中曼哈顿世界场景通过位姿解耦实现基于曼哈顿帧观测的无漂移旋转估计,而该场景的平移以及非曼哈顿世界场景的位姿采用追踪的点、线、面特征进行估计和优化;最后根据关键帧和相应位姿实现稠密建图。采用慕尼黑工业大学(technische universit?t münchen, TUM)数据集验证所提建图方法,经过与ORB-SLAM2算法比较,均方根误差平均减少0.24 cm,平均定位精度提高7.17%,验证了所提方法进行稠密建图的可行性和有效性。展开更多
文摘The idea of the hypothetical Magellanica Continent(Terra Australis Incognita)was introduced into China by the Jesuit missionaries during the seventeenth century.While not accepted by the Chinese government,it was affirmed and transmitted to the public by a few Chinese scholars,including Feng Yingjing,Cheng Bai'er,Zhang Huang,Xiong Mingyu,Xiong Renlin,You Yi,Zhou Yuqi,Jie Xuan,Wang Honghan,and Ye Zipei.Most of them communicated closely with the Jesuit missionaries,and several even helped the missionaries compose the maps.The concept was updated progressively by Matteo Ricci,Giulio Aleni,Johann Adam Schall von Bell,Francesco Sambiasi,and Ferdinand Verbiest.Chinese scholars copied the missionaries'relevant maps and textual introductions without much modification.However,they paid little attention to advancements in the idea,and many of them circulated outdated knowledge.It was not until the middle-and late-nineteenth century that Chinese scholars reexamined the correctness of this hypothetical continent.
文摘为提高ORB-SLAM2 (oriented fast and rotated brief, and simultaneous localization and mapping)系统的位姿估计精度并解决仅能生成稀疏地图的问题,提出了融合迭代最近点拟合(iterative closest point, ICP)算法与曼哈顿世界假说的位姿估计策略并在系统中加入稠密建图线程。首先通过ORB(oriented fast and rotated brief)特征点法、最小显著性差异(least-significant difference, LSD)算法和聚集层次聚类(agglomerative hierarchical clustering, AHC)方法提取点、线、面特征,其中点、线特征与上一帧匹配,面特征在全局地图匹配。然后采用基于surfel的稠密建图策略将图像划分为非平面与平面区域,非平面采用ICP算法计算位姿,平面则通过面与面的正交关系确定曼哈顿世界从而使用不同估计策略,其中曼哈顿世界场景通过位姿解耦实现基于曼哈顿帧观测的无漂移旋转估计,而该场景的平移以及非曼哈顿世界场景的位姿采用追踪的点、线、面特征进行估计和优化;最后根据关键帧和相应位姿实现稠密建图。采用慕尼黑工业大学(technische universit?t münchen, TUM)数据集验证所提建图方法,经过与ORB-SLAM2算法比较,均方根误差平均减少0.24 cm,平均定位精度提高7.17%,验证了所提方法进行稠密建图的可行性和有效性。
