Oriented and horizontal bounding box are two typical output forms in the field of remote sensing object detection. Most present state-of-the-art detectors perform object detection in Cartesian coordinates with anchor mechanism. In these methods, the design of oriented detectors is much more complicated than the horizontal ones, because the former usually needs to devise more complex rotated anchors. In this paper, we perform object detection in polar coordinates rather than in Cartesian coordinates, and propose a novel anchor-free detector for remote sensing images. Our model, which is named as Polar Remote Sensing Object Detector (P-RSDet), takes the center point of each object as the pole point and the horizontal positive direction as the polar axis to establish the polar coordinate system. In this coordinates system, P-RSDet unifies the representation of horizontal and oriented bounding box, and makes the acquisition of oriented output form be as simple as the horizontal one. Compared with previous detectors, the design of our network is simpler and fewer output parameters need to be regressed. Experiments on DOTA, UCAS-AOD and NWPU VHR-10 datasets show that our P-RSDet achieves competitive performances on both horizontal and oriented detection fields
翻译:在遥感物体探测领域,定向和横向捆绑框是两种典型的输出形式,大多数现有最先进的探测器在带有锚机制的笛卡尔坐标坐标上进行物体探测。在这些方法中,定向探测器的设计比水平探测器复杂得多,因为前者通常需要设计更复杂的旋转锚,因为前者通常需要设计更复杂的旋转锚。在本文中,我们在极地坐标而不是笛卡尔坐标上进行物体探测,并为遥感图像提出一个新的无锚定位探测器。我们的模型,称为极地遥感物体探测器(P-RSDet),以每个物体的中心点为极点,以极地轴为横向正向,建立极地坐标系统。在这个坐标系统中,P-RSDet将横向和定向捆绑框的表示统一起来,并使定向输出表的获取像水平坐标一样简单。与以前的探测器相比,我们的网络设计需要更简单、更少的输出参数才能被再次反射。在DOTA、UCAS-AOD和NWPU VHR-10的实验显示我们水平探测场上的竞争性性表现。