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33
Detailed real-time urban 3D reconstruction from video.
- IJCV,
, 2008
"... Abstract The paper presents a system for automatic, georegistered, real-time 3D reconstruction from video of urban scenes. The system collects video streams, as well as GPS and inertia measurements in order to place the reconstructed models in geo-registered coordinates. It is designed using curren ..."
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Cited by 185 (22 self)
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Abstract The paper presents a system for automatic, georegistered, real-time 3D reconstruction from video of urban scenes. The system collects video streams, as well as GPS and inertia measurements in order to place the reconstructed models in geo-registered coordinates. It is designed using current state of the art real-time modules for all processing steps. It employs commodity graphics hardware and standard CPU's to achieve real-time performance. We present the main considerations in designing the system and the steps of the processing pipeline. Our system extends existing algorithms to meet the robustness and variability necessary to operate out of the lab. To account for the large dynamic range of outdoor videos the processing pipeline estimates global camera gain changes in the feature tracking stage and efficiently compensates for these in stereo estimation without impacting the real-time performance. The required accuracy for many applications is achieved with a two-step stereo reconstruction process exploiting the redundancy across frames. We show results on real video sequences comprising hundreds of thousands of frames.
P.: Generic and real-time structure from motion
- In: BMVC (2007
"... We introduce a generic and incremental Structure from Motion method. By generic, we mean that the proposed method is independent of any specific camera model. During the incremental 3D reconstruction, parameters of 3D points and camera poses are refined simultaneously by a generic local bundle adjus ..."
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Cited by 39 (4 self)
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We introduce a generic and incremental Structure from Motion method. By generic, we mean that the proposed method is independent of any specific camera model. During the incremental 3D reconstruction, parameters of 3D points and camera poses are refined simultaneously by a generic local bundle adjustment that minimizes an angular error between rays. This method has three main advantages: it is generic, fast and accurate. The proposed method is evaluated by experiments on real data with three kinds of calibrated cameras: stereo rig, perspective and catadioptric cameras. 1
Fast and Robust Numerical Solutions to Minimal Problems for Cameras with Radial Distortion
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Improving numerical accuracy in gröbner basis polynomial equation solvers
- In International Conference on Computer Vision
, 2007
"... This paper presents techniques for improving the numerical stability of Gröbner basis solvers for polynomial equations. Recently Gröbner basis methods have been used succesfully to solve polynomial equations arising in global optimization e.g. three view triangulation and in many important minimal c ..."
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Cited by 22 (6 self)
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This paper presents techniques for improving the numerical stability of Gröbner basis solvers for polynomial equations. Recently Gröbner basis methods have been used succesfully to solve polynomial equations arising in global optimization e.g. three view triangulation and in many important minimal cases of structure from motion. Such methods work extremely well for problems of reasonably low degree, involving a few variables. Currently, the limiting factor in using these methods for larger and more demanding problems is numerical difficulties. In the paper we (i) show how to change basis in the quotient space R[x]/I and propose a strategy for selecting a basis which improves the conditioning of a crucial elimination step, (ii) use this technique to devise a Gröbner basis with improved precision and (iii) show how solving for the eigenvalues instead of eigenvectors can be used to improve precision further while retaining the same speed. We study these methods on some of the latest reported uses of Gröbner basis methods and demonstrate dramatically improved numerical precision using these new techniques making it possible to solve a larger class of problems than previously. 1.
A linear approach to motion estimation using generalized camera models
- In: CVPR
, 2008
"... A well-known theoretical result for motion estimation using the generalized camera model is that 17 corresponding image rays can be used to solve linearly for the motion of a generalized camera. However, this paper shows that for many common configurations of the generalized camera models (e.g., mul ..."
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Cited by 22 (7 self)
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A well-known theoretical result for motion estimation using the generalized camera model is that 17 corresponding image rays can be used to solve linearly for the motion of a generalized camera. However, this paper shows that for many common configurations of the generalized camera models (e.g., multi-camera rig, catadioptric camera etc.), such a simple 17-point algorithm does not exist, due to some previously overlooked ambiguities. We further discover that, despite the above ambiguities, we are still able to solve the motion estimation problem effectively by a new algorithm proposed in this paper. Our algorithm is essentially linear, easy to implement, and the computational efficiency is very high. Experiments on both real and simulated data show that the new algorithm achieves reasonably high accuracy as well. 1.
Robust 6dof motion estimation for non-overlapping, multi-camera systems
- in IEEE Workshop on Applications of Computer Vision
"... This paper introduces a novel, robust approach for 6DOF motion estimation of a multi-camera system with non-overlapping views. The proposed approach is able to solve the pose estimation, including scale, for a two camera system with non-overlapping views. In contrast to previous approaches, it degra ..."
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Cited by 14 (9 self)
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This paper introduces a novel, robust approach for 6DOF motion estimation of a multi-camera system with non-overlapping views. The proposed approach is able to solve the pose estimation, including scale, for a two camera system with non-overlapping views. In contrast to previous approaches, it degrades gracefully if the motion is close to degenerate. For degenerate motions the technique estimates the remaining 5DOF. The proposed technique is evaluated on real and synthetic sequences. 1.
A Column-Pivoting Based Strategy for Monomial Ordering in Numerical Gröbner Basis Calculations
"... Abstract. This paper presents a new fast approach to improving stability in polynomial equation solving. Gröbner basis techniques for equation solving have been applied successfully to several geometric computer vision problems. However, in many cases these methods are plagued by numerical problems. ..."
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Cited by 10 (3 self)
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Abstract. This paper presents a new fast approach to improving stability in polynomial equation solving. Gröbner basis techniques for equation solving have been applied successfully to several geometric computer vision problems. However, in many cases these methods are plagued by numerical problems. An interesting approach to stabilising the computations is to study basis selection for the quotient space C[x]/I. In this paper, the exact matrix computations involved in the solution procedure are clarified and using this knowledge we propose a new fast basis selection scheme based on QR-factorization with column pivoting. We also propose an adaptive scheme for truncation of the Gröbner basis to further improve stability. The new basis selection strategy is studied on some of the latest reported uses of Gröbner basis methods in computer vision and we demonstrate a fourfold increase in speed and nearly as good over-all precision as the previous SVD-based method. Moreover, we get typically get similar or better reduction of the largest errors. 1 1
Fast and Robust Numerical Solutions to Minimal Problems for Cameras with Radial Distortion
, 2009
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Image-Based Localization Using Hybrid Feature Correspondences
"... Where am I and what am I seeing? This is a classical vision problem and this paper presents a solution based on efficient use of a combination of 2D and 3D features. Given a model of a scene, the objective is to find the relative camera location of a new input image. Unlike traditional hypothesize-a ..."
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Cited by 5 (2 self)
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Where am I and what am I seeing? This is a classical vision problem and this paper presents a solution based on efficient use of a combination of 2D and 3D features. Given a model of a scene, the objective is to find the relative camera location of a new input image. Unlike traditional hypothesize-and-test methods that try to estimate the unknown camera position based on 3D model features only, or alternatively, based on 2D model features only, we show that using a mixture of such features, that is, a hybrid correspondence set, may improve performance. We use minimal cases of structure-from-motion for hypothesis generation in a RANSAC engine. For this purpose, several new and useful minimal cases are derived for calibrated, semi-calibrated and uncalibrated settings. Based on algebraic geometry methods, we show how these minimal hybrid cases can be solved efficiently. The whole approach has been validated on both synthetic and real data, and we demonstrate improvements compared to previous work.
