The Experts below are selected from a list of 44382 Experts worldwide ranked by ideXlab platform
Gerd Hirzinger - One of the best experts on this subject based on the ideXlab platform.
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more accurate pinhole Camera Calibration with imperfect planar target
International Conference on Computer Vision, 2011Co-Authors: Klaus H Strobl, Gerd HirzingerAbstract:This paper presents a novel approach to Camera Calibration that improves final accuracy with respect to standard methods using precision planar targets, even if now inaccurate, unmeasured, roughly planar targets can be used. The work builds on a recent trend in Camera Calibration, namely concurrent optimization of scene structure together with the intrinsic Camera parameters [4, 8, 1]. A novel formulation is presented that allows maximum likelihood estimation in the case of inaccurate targets, as it extends the Camera extrinsic parameters into a tight parametrization of the whole scene structure. It furthermore observes the special characteristics of multi-view perspective projection of planar targets. Its natural extensions to stereo Camera Calibration and hand-eye Calibration are also presented. Experiments demonstrate improvements in the parametrization of the Camera model as well as in eventual stereo reconstruction.
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ICCV Workshops - More accurate pinhole Camera Calibration with imperfect planar target
2011 IEEE International Conference on Computer Vision Workshops (ICCV Workshops), 2011Co-Authors: Klaus H Strobl, Gerd HirzingerAbstract:This paper presents a novel approach to Camera Calibration that improves final accuracy with respect to standard methods using precision planar targets, even if now inaccurate, unmeasured, roughly planar targets can be used. The work builds on a recent trend in Camera Calibration, namely concurrent optimization of scene structure together with the intrinsic Camera parameters [4, 8, 1]. A novel formulation is presented that allows maximum likelihood estimation in the case of inaccurate targets, as it extends the Camera extrinsic parameters into a tight parametrization of the whole scene structure. It furthermore observes the special characteristics of multi-view perspective projection of planar targets. Its natural extensions to stereo Camera Calibration and hand-eye Calibration are also presented. Experiments demonstrate improvements in the parametrization of the Camera model as well as in eventual stereo reconstruction.
Edmond Boyer - One of the best experts on this subject based on the ideXlab platform.
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On Using Silhouettes for Camera Calibration
2006Co-Authors: Edmond BoyerAbstract:This paper addresses the problem of Camera Calibration using object silhouettes in image sequences. It is known that silhouettes encode information on Camera parameters by the fact that their associated viewing cones should present a common intersection in space. In this paper, we investigate how to evaluate Calibration parameters given a set of silhouettes, and how to optimize such parameters with silhouette cues only. The objective is to provide on-line tools for silhouette based modeling applications in multiple Camera environments. Our contributions with respect to existing works in this field is first to establish the exact constraint that Camera parameters should satisfy with respect to silhouettes, and second to derive from this constraint new practical criteria to evaluate and to optimize Camera parameters. Results on both synthetic and real data illustrate the interest of the proposed framework.
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Camera Calibration Using Silhouettes
2005Co-Authors: Edmond BoyerAbstract:This report addresses the problem of estimating Camera parameters from images where object silhouettes only are known. Several modeling applications make use of silhouettes, and while Calibration methods are well known when considering points or lines matched along image sequences, the problem appears to be more difficult when considering silhouettes. However, such primitives encode also information on Camera parameters by the fact that their associated viewing cones should present a common intersection in space. In this paper, we investigate the problem both on the theoretical and practical viewpoint. In particular, we clarify why, and how, a set of image silhouettes of the same scene give constraints on Camera parameters; these constraints justifying a Calibration approach. The main contributions of this paper with respect to existing works is first to establish the optimal criterion that Camera parameters should satisfy with respect to silhouettes, and second to provide a practical approach based on this criterion. Results on both synthetic and real data are shown to give insights into the method potential for Camera Calibration.
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Camera Calibration and 3d reconstruction from single images using parallelepipeds
International Conference on Computer Vision, 2001Co-Authors: M Wilczkowiak, Edmond Boyer, Peter SturmAbstract:In this paper parallelepipeds and their use in Camera Calibration and 3D reconstruction processes are studied. Parallelepipeds naturally characterize rigidity constraints present in a scene, such as parallelism and orthogonality. A subclass of parallelepipeds-the cuboids-has been frequently used over the past to partially calibrate Cameras. However, the full potential of parallelepipeds, in Camera Calibration as well as in scene reconstruction, has never been clearly established. We propose a new framework for the use of parallelepipeds which is based on an extensive study of this potential. In particular, we exhibit the complete duality that exists between the intrinsic metric characteristics of a parallelepiped and the intrinsic parameters of a Camera. Our framework allows to fully exploit parallelepipeds and thus overcomes several limitations of Calibration approaches based on cuboids. To illustrate this framework, we present an original and very efficient interactive method for 3D reconstruction from single images. This method allows to quickly build a scene model from a single uncalibrated image.
Klaus H Strobl - One of the best experts on this subject based on the ideXlab platform.
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more accurate pinhole Camera Calibration with imperfect planar target
International Conference on Computer Vision, 2011Co-Authors: Klaus H Strobl, Gerd HirzingerAbstract:This paper presents a novel approach to Camera Calibration that improves final accuracy with respect to standard methods using precision planar targets, even if now inaccurate, unmeasured, roughly planar targets can be used. The work builds on a recent trend in Camera Calibration, namely concurrent optimization of scene structure together with the intrinsic Camera parameters [4, 8, 1]. A novel formulation is presented that allows maximum likelihood estimation in the case of inaccurate targets, as it extends the Camera extrinsic parameters into a tight parametrization of the whole scene structure. It furthermore observes the special characteristics of multi-view perspective projection of planar targets. Its natural extensions to stereo Camera Calibration and hand-eye Calibration are also presented. Experiments demonstrate improvements in the parametrization of the Camera model as well as in eventual stereo reconstruction.
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ICCV Workshops - More accurate pinhole Camera Calibration with imperfect planar target
2011 IEEE International Conference on Computer Vision Workshops (ICCV Workshops), 2011Co-Authors: Klaus H Strobl, Gerd HirzingerAbstract:This paper presents a novel approach to Camera Calibration that improves final accuracy with respect to standard methods using precision planar targets, even if now inaccurate, unmeasured, roughly planar targets can be used. The work builds on a recent trend in Camera Calibration, namely concurrent optimization of scene structure together with the intrinsic Camera parameters [4, 8, 1]. A novel formulation is presented that allows maximum likelihood estimation in the case of inaccurate targets, as it extends the Camera extrinsic parameters into a tight parametrization of the whole scene structure. It furthermore observes the special characteristics of multi-view perspective projection of planar targets. Its natural extensions to stereo Camera Calibration and hand-eye Calibration are also presented. Experiments demonstrate improvements in the parametrization of the Camera model as well as in eventual stereo reconstruction.
Huatsung Chen - One of the best experts on this subject based on the ideXlab platform.
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geometry based Camera Calibration using five point correspondences from a single image
IEEE Transactions on Circuits and Systems for Video Technology, 2017Co-Authors: Huatsung ChenAbstract:As an essential step in many computer vision tasks, Camera Calibration has been studied extensively. In this paper, we propose a novel Calibration technique that, based on geometric analysis, Camera parameters can be estimated effectively and accurately from just one view of only five corresponding points. Our core contribution is the geometric analysis for deriving the basic equations to realize Camera Calibration from four coplanar corresponding points and a fifth noncoplanar one. The position, orientation, and focal length of a zooming Camera can be directly estimated with unique solution. The estimated parameters are further optimized by the bundle adjustment technique. The proposed Calibration method is examined and evaluated on both computer simulated data and real images. The experimental results confirm the validity of the proposed method that Camera parameters can be estimated with sufficient accuracy using just five-point correspondences from a single image, even in the presence of image noise.
Jean Ponce - One of the best experts on this subject based on the ideXlab platform.
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Accurate Camera Calibration from multi-view stereo and bundle adjustment
International Journal of Computer Vision, 2009Co-Authors: Yasutaka Furukawa, Jean PonceAbstract:The advent of high-resolution digital Cameras and sophisticated multi-view stereo algorithms offers the promise of unprecedented geometric fidelity in image-based modeling tasks, but it also puts unprecedented demands on Camera Calibration to fulfill these promises. This paper presents a novel approach to Camera Calibration where top-down information from rough Camera parameter estimates and the output of a multi-view-stereo system on scaled-down input images is used to effectively guide the search for additional image correspondences and significantly improve Camera Calibration parameters using a standard bundle ad-justment algorithm (Lourakis and Argyros 2008). The pro-posed method has been tested on six real datasets including objects without salient features for which image correspon-dences cannot be found in a purely bottom-up fashion, and objects with high curvature and thin structures that are lost in visual hull construction even with small errors in Camera parameters. Three different methods have been used to qual-itatively assess the improvements of the Camera parameters. The implementation of the proposed algorithm is publicly available at Furukawa and Ponce (2008b).
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accurate Camera Calibration from multi view stereo and bundle adjustment
Computer Vision and Pattern Recognition, 2008Co-Authors: Yasutaka Furukawa, Jean PonceAbstract:The advent of high-resolution digital Cameras and sophisticated multi-view stereo algorithms offers the promises of unprecedented geometric fidelity in image-based modeling tasks, but it also puts unprecedented demands on Camera Calibration to fulfill these promises. This paper presents a novel approach to Camera Calibration where top-down information from rough Camera parameter estimates and the output of a publicly available multiview-stereo system (Furukawa et al.) on scaled-down input images are used to effectively guide the search for additional image correspondences and significantly improve Camera Calibration parameters using a standard bundle adjustment algorithm (Lourakis et al.). The proposed method has been tested on several real datasets-including objects without salient features for which image correspondences cannot be found in a purely bottom-up fashion, and image-based modeling tasks-including the construction of visual hulls where thin structures are lost without our Calibration procedure.
