@conference {11982,
	title = {Global rigidity constraints in image displacement fields},
	booktitle = {Proceedings of Fifth International Conference on Computer Vision, 1995},
	year = {1995},
	month = {1995/06/20/23},
	pages = {245 - 250},
	publisher = {IEEE},
	organization = {IEEE},
	abstract = {Image displacement fields-optical flow fields, stereo disparity fields, normal flow fields-due to rigid motion possess a global geometric structure which is independent of the scene in view. Motion vectors of certain lengths and directions are constrained to lie on the imaging surface at particular loci whose location and form depends solely on the 3D motion parameters. If optical flow fields or stereo disparity fields are considered, then equal vectors are shown to lie on conic sections. Similarly, for normal motion fields, equal vectors lie within regions whose boundaries also constitute conics. By studying various properties of these curves and regions and their relationships, a characterization of the structure of rigid motion fields is given. The goal of this paper is to introduce a concept underlying the global structure of image displacement fields. This concept gives rise to various constraints that could form the basis of algorithms for the recovery of visual information from multiple views},
	keywords = {3D motion parameters, algorithms, Automation, Computer science, Computer vision, conic sections, curves, equal vectors, Fluid flow measurement, global geometric structure, global rigidity constraints, image displacement fields, Image motion analysis, Image segmentation, Image sequences, imaging surface, Laboratories, Layout, Motion estimation, Motion measurement, motion vectors, multiple views, normal flow fields, optical flow fields, regions, rigid motion, stereo disparity fields, Stereo vision, vectors, visual information recovery},
	isbn = {0-8186-7042-8},
	doi = {10.1109/ICCV.1995.466779},
	author = {Ferm{\"u}ller, Cornelia and Aloimonos, J.}
}
@conference {14168,
	title = {Global rigidity constraints in image displacement fields},
	booktitle = {, Fifth International Conference on Computer Vision, 1995. Proceedings},
	year = {1995},
	month = {1995/06/20/23},
	pages = {245 - 250},
	publisher = {IEEE},
	organization = {IEEE},
	abstract = {Image displacement fields-optical flow fields, stereo disparity fields, normal flow fields-due to rigid motion possess a global geometric structure which is independent of the scene in view. Motion vectors of certain lengths and directions are constrained to lie on the imaging surface at particular loci whose location and form depends solely on the 3D motion parameters. If optical flow fields or stereo disparity fields are considered, then equal vectors are shown to lie on conic sections. Similarly, for normal motion fields, equal vectors lie within regions whose boundaries also constitute conics. By studying various properties of these curves and regions and their relationships, a characterization of the structure of rigid motion fields is given. The goal of this paper is to introduce a concept underlying the global structure of image displacement fields. This concept gives rise to various constraints that could form the basis of algorithms for the recovery of visual information from multiple views},
	keywords = {3D motion parameters, algorithms, Automation, Computer science, Computer vision, conic sections, curves, equal vectors, Fluid flow measurement, global geometric structure, global rigidity constraints, image displacement fields, Image motion analysis, Image segmentation, Image sequences, imaging surface, Laboratories, Layout, Motion estimation, Motion measurement, motion vectors, multiple views, normal flow fields, optical flow fields, regions, rigid motion, stereo disparity fields, Stereo vision, vectors, visual information recovery},
	isbn = {0-8186-7042-8},
	doi = {10.1109/ICCV.1995.466779},
	author = {Ferm{\"u}ller, Cornelia and Aloimonos, J.}
}
@conference {14174,
	title = {Global 3D motion estimation},
	booktitle = {, 1993 IEEE Computer Society Conference on Computer Vision and Pattern Recognition, 1993. Proceedings CVPR {\textquoteright}93},
	year = {1993},
	month = {1993/06/15/17},
	pages = {415 - 421},
	publisher = {IEEE},
	organization = {IEEE},
	abstract = {It is shown how a monocular observer can estimate its 3D motion relative to the scene by using normal flow measurements in a global and qualitative way. It is proved that local normal flow measurements form global patterns in the image plane. The position of these patterns is related to the 3D motion parameters. By locating some of these patterns, which depend only on subsets of the motion parameters, through a simple search technique, the 3D motion parameters can be found. The proposed algorithmic procedure is very robust, since it is not affected by small perturbations in the normal flow measurements. The direction of translation and the axis of rotation can be estimated with up to 100\% error in the image measurements},
	keywords = {3D motion parameters, Automation, axis of rotation, Computer vision, direction of translation, Educational institutions, Equations, Fluid flow measurement, global 3D motion estimation, Laboratories, Layout, monocular observer, Motion estimation, Motion measurement, normal flow measurements, Robustness, Rotation measurement, search problems, search technique, State estimation},
	isbn = {0-8186-3880-X},
	doi = {10.1109/CVPR.1993.341097},
	author = {Ferm{\"u}ller, Cornelia}
}
@conference {14176,
	title = {Motion constraint patterns},
	booktitle = {, Proceedings of IEEE Workshop on Qualitative Vision, 1993},
	year = {1993},
	month = {1993/06/14/},
	pages = {128 - 139},
	publisher = {IEEE},
	organization = {IEEE},
	abstract = {The problem of egomotion recovery has been treated by using as input local image motion, with the published algorithms utilizing the geometric constraint relating 2-D local image motion (optical flow, correspondence, derivatives of the image flow) to 3-D motion and structure. Since it has proved very difficult to achieve accurate input (local image motion), a lot of effort has been devoted to the development of robust techniques. A new approach to the problem of egomotion estimation is taken, based on constraints of a global nature. It is proved that local normal flow measurements form global patterns in the image plane. The position of these patterns is related to the three dimensional motion parameters. By locating some of these patterns, which depend only on subsets of the motion parameters, through a simple search technique, the 3-D motion parameters can be found. The proposed algorithmic procedure is very robust, since it is not affected by small perturbations in the normal flow measurements. As a matter of fact, since only the sign of the normal flow measurement is employed, the direction of translation and the axis of rotation can be estimated with up to 100\% error in the image measurements},
	keywords = {3D motion parameters, Automation, computational geometry, Computer vision, correspondence, Educational institutions, egomotion recovery, Fluid flow measurement, geometric constraint, Geometrical optics, Image motion analysis, image plane, Laboratories, local image motion, local normal flow measurements, Motion estimation, Motion measurement, motion parameters, optical flow, Rotation measurement},
	isbn = {0-8186-3692-0},
	doi = {10.1109/WQV.1993.262942},
	author = {Ferm{\"u}ller, Cornelia}
}
