摘要:
Online camera calibration methods have been proposed whereby calibration information is extracted from the images that the system captures during normal operation and is used to continually update system parameters. However, such existing methods do not cope well with structure-poor scenes having little texture and/or 3D structure such as in a home or office environment. By considering camera families (a set of cameras that are manufactured at least partially in a common manner) it is possible to provide calibration methods which are suitable for use with structure-poor scenes. A prior distribution of camera parameters for a family of cameras is estimated and used to obtain accurate calibration results for individual cameras of the camera family even where the calibration is carried out online, in an environment which is structure-poor.
摘要:
Online camera calibration methods have been proposed whereby calibration information is extracted from the images that the system captures during normal operation and is used to continually update system parameters. However, such existing methods do not cope well with structure-poor scenes having little texture and/or 3D structure such as in a home or office environment. By considering camera families (a set of cameras that are manufactured at least partially in a common manner) it is possible to provide calibration methods which are suitable for use with structure-poor scenes. A prior distribution of camera parameters for a family of cameras is estimated and used to obtain accurate calibration results for individual cameras of the camera family even where the calibration is carried out online, in an environment which is structure-poor.
摘要:
A pose of an object is estimated by first defining a set of pair features as pairs of geometric primitives, wherein the geometric primitives include oriented surface points, oriented boundary points, and boundary line segments. Model pair features are determined based on the set of pair features for a model of the object. Scene pair features are determined based on the set of pair features from data acquired by a 3D sensor, and then the model pair features are matched with the scene pair features to estimate the pose of the object.
摘要:
A three-dimensional (3D) pose of a 3D object in an environment is determined by extracting features from an image acquired of the environment by a camera. The features are matched to a 3D model of the environment to determine correspondences. A camera reference frame of the image and a world reference frame of the environment are transformed to a corresponding intermediate camera reference frame and a corresponding world reference frame using the correspondences. Geometrical constraints are applied to the intermediate camera reference frame and the intermediate world reference frame to obtain a constrained intermediate world reference frame and a constrained world reference frame. The 3D pose is then determined from parameters of the constrained intermediate world reference frame and the constrained world reference frame.
摘要:
A location and orientation in an environment is determined by first acquiring a real omni-directional image of an unknown skyline in the environment. A set of virtual omni-directional images of known skylines are synthesized from a 3D model of the environment, wherein each virtual omni-directional image is associated with a known location and orientation. The real omni-directional image with each virtual omni-directional images to determine a best matching virtual omni-directional image with the associated known location and orientation.
摘要:
Poses of a movable camera relative to an environment are obtained by determining point correspondences from a set of initial images and then applying 2-point motion estimation to the point correspondences to determine a set of initial poses of the camera. A point cloud is generated from the set of initial poses and the point correspondences. Then, for each next image, the point correspondences and corresponding poses are determined, while updating the point cloud.
摘要:
An image is segmented into superpixels by constructing a graph with vertices connected by edges, wherein each vertex corresponds to a pixel in the image, and each edge is associated with a weight indicating a similarity of the corresponding pixels, A subset of edges in the graph are selected to segment the graph into subgraphs, wherein the selecting maximizes an objective function based on an entropy rate and a balancing term. The edges with maximum gains are added to the graph until a number of subgraphs is equal to some threshold.
摘要:
A three-dimensional (3D) location of a reflection point of a ray between a point in a scene (PS) and a center of projection (COP) of a camera of a catadioptric system is determined. The catadioptric system is non-central and includes the camera and a reflector, wherein a surface of the reflector is a quadric surface rotationally symmetric around an axis of symmetry. The 3D location of the reflection point is determined based on a law of reflection, an equation of the reflector, and an equation describing a reflection plane defined by the COP, the PS, and a point of intersection of a normal to the reflector at the reflection point with the axis of symmetry.
摘要:
Embodiment of invention discloses a system and a method for determining a three-dimensional (3D) location of a folding point of a ray between a point in a scene (PS) and a center of projection (COP) of a camera of a catadioptric system. One embodiment maps the catadioptric system, including 3D locations of the PS and the COP on a two-dimensional (2D) plane defined by an axis of symmetry of a folding optical element and the PS to produce a conic and 2D locations of the PS and COP on the 2D plane, and determines a 2D location of the folding point on the 2D plane based on the conic, the 2D locations of the PS and the COP. Next, the embodiment determines the 3D location of the folding point from the 2D location of the folding point on the 2D plane.
摘要:
Three-dimensional data are registered by selecting a first set of primitives from the data in a first coordinate system, wherein the first set of primitives includes at least one plane, at least one point, and a third primitive that is either a point or a plane, and selecting a second set of primitives from the data in a second coordinate system, wherein the second set of primitives includes at least one plane, at least one point, and a third primitive corresponding to the third primitive in the first set of primitives. Then, the planes are registered with each other, as are the points, to obtain registered primitives.