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Estimating six degrees of freedom poses of a planar object from images is an important problem with numerous applications ranging from robotics to augmented reality. While the state-of-the-art Perspective-n-Point algorithms perform well in pose estimation, the success hinges on whether feature points can be extracted and matched correctly on target objects with rich texture. In this work, we propose a two-step robust direct method for six-dimensional pose estimation that performs accurately on both textured and textureless planar target objects. First, the pose of a planar target object with respect to a calibrated camera is approximately estimated by posing it as a template matching problem. Second, each object pose is refined and disambiguated using a dense alignment scheme. Extensive experiments on both synthetic and real datasets demonstrate that the proposed direct pose estimation algorithm performs favorably against state-of-the-art feature-based approaches in terms of robustness and accuracy under varying conditions. Furthermore, we show that the proposed dense alignment scheme can also be used for accurate pose tracking in video sequences.

We propose a system for real-time six degrees of freedom (6DoF) tracking of a passive stylus that achieves sub-millimeter accuracy, which is suitable for writing or drawing in mixed reality applications. Our system is particularly easy to implement, requiring only a monocular camera, a 3D printed dodecahedron, and hand-glued binary square markers. The accuracy and performance we achieve are due to model-based tracking using a calibrated model and a combination of sparse pose estimation and dense alignment. We demonstrate the system performance in terms of speed and accuracy on a number of synthetic and real datasets, showing that it can be competitive with state-of-the-art multi-camera motion capture systems. We also demonstrate several applications of the technology ranging from 2D and 3D drawing in VR to general object manipulation and board games.

Real-time recovering an accurate 6 DoF pose of a known planar target is essential for augmented reality and robotics applications. Despite several pose estimation tracking systems have been proposed over recent years, there is still the need for a more efficient and more accurate solution for general planar objects. In this work, we develop an innovative GPU implementation of a real-time pose estimation and tracking system. It consists of a pose estimation unit and a pose tracker unit. While the former computes an initial pose of a target using direct method, the latter realizes accurate pose tracking with a hierarchical search scheme. Experiments on both synthetic and real datasets demonstrate that the proposed algorithm performs favorably with various planar targets. By implementing our method on an embedded GPU, the system achieves to work at 11 FPS and is suitable for real-time applications.

Estimating 3D pose of a known object from a given 2D image is an important problem with numerous studies for robotics and augmented reality applications. While the state-of-the-art Perspective-n-Point algorithms perform well in pose estimation, the success hinges on whether feature points can be extracted and matched correctly on targets with rich texture. In this work, we propose a robust direct method for 3D pose estimation with high accuracy that performs well on both textured and textureless planar targets. First, the pose of a planar target with respect to a calibrated camera is approximately estimated by posing it as a template matching problem. Next, the object pose is further refined and disambiguated with a gradient descent search scheme. Extensive experiments on both synthetic and real datasets demonstrate the proposed direct pose estimation algorithm performs favorably against state-of-the-art feature-based approaches in terms of robustness and accuracy under several varying conditions.

Estimation of a object pose from camera is a well-developing topic in computer vision. In theory, the pose from a calibrated camera can be uniquely determined. But in practice, most of the real-time pose estimation algorithms suffer from pose ambiguity due to low accuracy of the target object. We think that pose ambiguityiXtwo distinct local minima of the according error functioniXexist because of the phenomenon of geometric illusions. Both of the ambiguous poses are plausible. After obtaining the solution of two minima (pose candidates), we develop a real-time algorithm for stable pose estimation of a target objects with a motion model. In the experimental results, the proposed algorithm diminish the significance of pose jumping and pose jittering effectively. To the best of our knowledge, this is the first work to solve the pose ambiguity problem with motion model in real-time application.