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Epipolar Geometry for Central Catadioptric Cameras
, 2002
"... Central catadioptric cameras are cameras which combine lenses and mirrors to capture a very wide field of view with a central projection. In this paper we extend the classical epipolar geometry of perspective cameras to all central catadioptric cameras. Epipolar geometry is formulated as the geometr ..."
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Cited by 85 (5 self)
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Central catadioptric cameras are cameras which combine lenses and mirrors to capture a very wide field of view with a central projection. In this paper we extend the classical epipolar geometry of perspective cameras to all central catadioptric cameras. Epipolar geometry is formulated as the geometry of corresponding rays in a three-dimensional space. Using the model of image formation of central catadioptric cameras, the constraint on corresponding image points is then derived. It is shown that the corresponding points lie on epipolar conics. In addition, the shape of the conics for all types of central catadioptric cameras is classified. Finally, the theory is verified by experiments with real central catadioptric cameras.
For a recent report
- Core Experiment ROI 1: ROI refinement", ISO/IEC JTC1/SC29/WG1 N990
, 1995
"... Abstract This report gives a report of the developed methods and techniques of multimodal recognizers that are used in the M4 domain. This includes the description of recognizers in the auditory domain, like phoneme recognition and localization, the video domain, represented by gesture recognition, ..."
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Cited by 42 (2 self)
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Abstract This report gives a report of the developed methods and techniques of multimodal recognizers that are used in the M4 domain. This includes the description of recognizers in the auditory domain, like phoneme recognition and localization, the video domain, represented by gesture recognition, person identification, person tracking and gaze tracking, and multimodal multimodal approaches for tracking and localization of people. The outcome of these approaches give a sufficient input for the more higher level approaches in WP3 for efficient meeting analysis and multimodal access. M4 Deliverable D2.2 1
Multi-view geometry for general camera models
- PROCEEDINGS OF THE 2005 IEEE COMPUTER SOCIETY CONFERENCE ON COMPUTER VISION AND PATTERN RECOGNITION (CVPR’05) - VOLUME 1
, 2005
"... We consider calibration and structure from motion tasks for a previously introduced, highly general imaging model, where cameras are modeled as possibly unconstrained sets of projection rays. This allows to describe most existing camera types (at least for those operating in the visible domain), in ..."
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Cited by 34 (4 self)
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We consider calibration and structure from motion tasks for a previously introduced, highly general imaging model, where cameras are modeled as possibly unconstrained sets of projection rays. This allows to describe most existing camera types (at least for those operating in the visible domain), including pinhole cameras, sensors with radial or more general distortions, catadioptric cameras (central or non-central), etc. Generic algorithms for calibration and structure from motion tasks (pose and motion estimation and 3D point triangulation) are outlined. The foundation for a multi-view geometry of non-central cameras is given, leading to the formulation of multi-view matching tensors, analogous to the fundamental matrices, trifocal and quadrifocal tensors of perspective cameras. Besides this, we also introduce a natural hierarchy of camera models: the most general model has unconstrained projection rays whereas the most constrained model dealt with here is the central model, where all rays pass through a single point.
A method for 3d reconstruction of piecewise planar objects from single panoramic images
- 1st International IEEE Workshop on Omnidirectional Vision at CVPR, 2000
"... We present an approach for 3D reconstruction of objects from a single panoramic image. Obviously, constraints on the 3D structure are needed to perform this task. Our approach is based on user-provided coplanarity, perpendicularity and parallelism constraints. The method is described in detail for t ..."
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Cited by 18 (1 self)
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We present an approach for 3D reconstruction of objects from a single panoramic image. Obviously, constraints on the 3D structure are needed to perform this task. Our approach is based on user-provided coplanarity, perpendicularity and parallelism constraints. The method is described in detail for the case of a parabolic mirror-based omnidirectional sensor and results are provided.
Panoramic cameras for 3D computation
, 2000
"... In this paper, we review design and principles of existing panoramic cameras. Panoramic cameras which enable 3D computation in reasonable time for real time applications are emphasized. We classify panoramic cameras w.r.t. their construction, field of view, and existence of a single projective cente ..."
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Cited by 12 (1 self)
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In this paper, we review design and principles of existing panoramic cameras. Panoramic cameras which enable 3D computation in reasonable time for real time applications are emphasized. We classify panoramic cameras w.r.t. their construction, field of view, and existence of a single projective center. Using this classification we state a utility of the central catadioptric panoramic cameras. We show from which mirrors and conventional cameras can be constructed and expose that they are the only ones for which the epipolar geometry can be simply generalized. 1 Introduction A wide field of view eases the search for correspondences as corresponding points do not so often disappear from the field of view and helps to stabilize ego-motion estimation algorithms so that the rotation of the camera can be well distinguished from its translation [6]. As the panoramic cameras see a large part of the scene around them in each image, they can provide more complete reconstructions from fewer image...
Framework for designing catadioptric projection and imaging systems
- In Proc. IEEE International Workshop on Projector-Camera Systems
, 2003
"... Current projector systems assume a frontal planar dis-play surface. In order to project onto arbitrary surfaces, one must warp the images digitally before projection. As a result, the image quality degrades due to image re-sampling. In this paper, we propose catadioptric pro-jector systems that use ..."
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Cited by 10 (0 self)
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Current projector systems assume a frontal planar dis-play surface. In order to project onto arbitrary surfaces, one must warp the images digitally before projection. As a result, the image quality degrades due to image re-sampling. In this paper, we propose catadioptric pro-jector systems that use lenses and mirrors, to optically warp images. The warp is specified as a map from points in the image to points on the display surface, called the image-to-scene map. The key problem then is to deter-mine the mirror shape that implements this map. Pre-vious methods for mirror design were case-specific and required considerable designer interaction and skill. In contrast, we present a fully automatic algorithm to deter-mine the mirror shape for any image-to-scene map. We
Face tracking in meeting room scenarios using omnidirectional views
- Proceedings Intern. Conference on Pattern Recognition (ICPR
, 2004
"... The robust localization and tracking of faces in video streams is a fundamental concern for many subsequent multi-modal recognition approaches. Especially in meeting scenarios several independent processing queues often exist that use the position and gaze of faces, such as group action- and face re ..."
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Cited by 10 (5 self)
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The robust localization and tracking of faces in video streams is a fundamental concern for many subsequent multi-modal recognition approaches. Especially in meeting scenarios several independent processing queues often exist that use the position and gaze of faces, such as group action- and face recognizers. The costs for multiple camera recordings of meeting scenarios are obviously higher compared to those of a single omnidirectional camera setup. Therefore it would be desirable to use these easier to acquire omnidirectional recordings. The present work presents an implementation of a robust particle filter based face-tracker using omnidirectional views. It is shown how omnidirectional images have to be unwarped before they can be processed by localization and tracking systems being invented for undistorted material. The performance of the system is evaluated on a part of the PETS-ICVS 2003 Smart Meeting Room dataset. 1.
Range Estimation from a Pair of Omnidirectional Images
- Proc. IEEE Int. Conf. on Robotics and Automation, Seoul, Korea
, 2001
"... In this paper we address the problem of recovering range information from a pair of images obtained from camera viewpoints whose relative poses are known (stereo vision) . The images we deal with are cylindrical reprojections of images captured by an omnidirectional vision sensor. Images obtained by ..."
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Cited by 4 (3 self)
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In this paper we address the problem of recovering range information from a pair of images obtained from camera viewpoints whose relative poses are known (stereo vision) . The images we deal with are cylindrical reprojections of images captured by an omnidirectional vision sensor. Images obtained by such a device have a relatively low spatial resolution in comparison to standard camera images. We analyze the sensitivity of range estimation from image correspondences with respect to errors caused by discretization. The analysis reveals the significance of obtaining subpixel accuracy for range estimation. We present our method and experimental results. The results indicate that high accuracy range estimates can be obtained using our method.
Classification and Characterization of Image Acquisition for 3D Scene Visualization and Reconstruction Applications
"... This paper discusses the techniques of image acquisition for 3D scene visualization and reconstruction applications (3DSVR). The existing image acquisition approaches in 3DSVR applications are briefly reviewed. There are still lacks of the studies about what principles are essential in the design ..."
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Cited by 3 (1 self)
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This paper discusses the techniques of image acquisition for 3D scene visualization and reconstruction applications (3DSVR). The existing image acquisition approaches in 3DSVR applications are briefly reviewed. There are still lacks of the studies about what principles are essential in the design and how we can characterize the limitations of an image acquisition model in a formal way. This paper addresses so me of the main characteristics of existing image acquisition approaches, summarized through a classification scheme and illustrated with many examples. The results of the classification lead to general characterizations in establishing the notions (basic components) for design, analysis and assessment of image acquisition models. The notions introduced include: focal set, receptor set, reflector set etc. The definitions of the notions are given and supported with various examples (e.g. concentric panoramas , cataoptrical panoramas). The observations, important issues, a...
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, 2001
"... The technical description of the deliverable D2: ”Mirror implementation”. ..."
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Cited by 3 (0 self)
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The technical description of the deliverable D2: ”Mirror implementation”.
