Abstract: A system and method to calibrate an uncollimated laser diode for three-dimensional imaging applications. A method includes providing an optical comparator having an uncollimated laser diode as a light source to generate a shadow with sharp boundaries when used to illuminate an opaque occluder, wherein a two lines source model of light propagation is used to describe a behavior of the uncollimated laser diode, the two lines source model defined by two three-dimensional (3D) lines as model parameters, the uncollimated laser diode calibrated by estimating the two lines as a function of a sample of a ray field emitted by the uncollimated laser diode.

Abstract: A system and method to capture the surface geometry a three-dimensional object in a scene using unsynchronized structured lighting is disclosed. The method and system includes a pattern projector configured and arranged to project a sequence of image patterns onto the scene at a pattern frame rate, a camera configured and arranged to capture a sequence of unsynchronized image patterns of the scene at an image capture rate, and a processor configured and arranged to synthesize a sequence of synchronized image frames from the unsynchronized image patterns of the scene. Each of the synchronized image frames corresponds to one image pattern of the sequence of image patterns.

Abstract: The invention is a computer implemented method, device, system, or article for reconstructing a surface of an object from a data set of the object comprising a plurality of partially oriented three dimensional points; each partially oriented three dimensional point comprising a point location and a point orientation vector; the point orientation vector being a fully specified point orientation vector, a partially specified orientation vector, or a missing point orientation vector. In particular, the invention comprises estimating the partially specified point orientation vectors and the missing point orientation vectors, resulting in a set of completely oriented three dimensional points; estimating a signed distance function from the set of completely oriented three dimensional points, and evaluating the smooth signed distance function on vertices of a volumetric mesh.

Abstract: A system and method to capture the surface geometry a three-dimensional object in a scene using unsynchronized structured lighting is disclosed. The method and system includes a pattern projector configured and arranged to project a sequence of image patterns onto the scene at a pattern frame rate, a camera configured and arranged to capture a sequence of unsynchronized image patterns of the scene at an image capture rate, and a processor configured and arranged to synthesize a sequence of synchronized image frames from the unsynchronized image patterns of the scene. Each of the synchronized image frames corresponds to one image pattern of the sequence of image patterns.

Abstract: Techniques for scanning through structured light techniques that are robust to global illumination effects and that provide an accurate determination of position as provided. According to some aspects, described techniques may be computationally efficient compared with conventional techniques by making use of a novel approach of selecting frequencies of patterns for projection onto a target that mathematically enable efficient calculations. In particular, the selected frequencies may be chosen so that there is a known relationship between the frequencies. This relationship may be derived from Chebyshev polynomials and also relates the chosen frequencies to a low frequency pattern.

Abstract: A method obtains the shape of a target by projecting and recording images of dual frequency fringe patterns. Locations in each projector image plane are encoded into the patterns and projected onto die target while images are recorded. The resulting images show the patterns superimposed onto the target. The images are decoded to recover relative phase values for the patterns primary and dual frequencies. The relative phases are unwrapped into absolute phases and converted back to projector image plane locations. The relation between camera pixels and decoded projector locations is saved as a correspondence image representing the measured shape of the target. Correspondence images with a geometric triangulation method create a 3D model of the target. Dual frequency hinge patterns have a low frequency embedded into a high frequency sinusoidal, both frequencies are recovered in closed form by the decoding method, thus, enabling direct phase unwrapping.

Abstract: A system and method to capture the surface geometry a three-dimensional object in a scene using unsynchronized structured lighting is disclosed. The method and system includes a pattern projector configured and arranged to project a sequence of image patterns onto the scene at a pattern frame rate, a camera configured and arranged to capture a sequence of unsynchronized image patterns of the scene at an image capture rate, and a processor configured and arranged to synthesize a sequence of synchronized image frames from the unsynchronized image patterns of the scene. Each of the synchronized image frames corresponds to one image pattern of the sequence of image patterns.

Abstract: The invention is a computer implemented method, device, system, or article for reconstructing a surface of an object. In particular, the invention comprises estimating a non-convex hull signed distance function parameters from a data set of an object and evaluating the non-convex hull signed distance function on vertices of a volumetric mesh. The invention further comprises approximating the zero level set of the non-convex hull signed distance function by a polygonal mesh using an isosurface algorithm to provide surface reconstruction of an object.

Abstract: The invention is a computer implemented method, device, system, or article for reconstructing a surface of an object. In particular, the invention comprises estimating a non-convex hull signed distance function parameters from a data set of an object and evaluating the non-convex hull signed distance function on vertices of a volumetric mesh. The invention further comprises approximating the zero level set of the non-convex hull signed distance function by a polygonal mesh using an isosurface algorithm to provide surface reconstruction of an object.

Abstract: A method for the problem of reconstructing a watertight surface defined by an implicit equation from a finite set of oriented points. As in other surface reconstruction approaches disctretizations of this continuous formulation reduce to the solution of sparse least-squares problems. Rather than forcing the implicit function to approximate the indicator function of the volume bounded by the surface, in the present formulation the implicit function is a smooth approximation of the signed distance function to the surface. Then solution thus introduced is a very simple hybrid FE/FD discretization, which together with an octree partitioning of space, and the Dual Marching Cubes algorithm produces accurate and adaptive meshes.

Abstract: A system and method to calibrate an uncollimated laser diode for three-dimensional imaging applications. A method includes providing an optical comparator having an uncollimated laser diode as a light source to generate a shadow with sharp boundaries when used to illuminate an opaque occluder, wherein a two lines source model of light propagation is used to describe a behavior of the uncollimated laser diode, the two lines source model defined by two three-dimensional (3D) lines as model parameters, the uncollimated laser diode calibrated by estimating the two lines as a function of a sample of a ray field emitted by the uncollimated laser diode.

Abstract: Techniques for scanning through structured light techniques that are robust to global illumination effects and that provide an accurate determination of position as provided. According to some aspects, described techniques may be computationally efficient compared with conventional techniques by making use of a novel approach of selecting frequencies of patterns for projection onto a target that mathematically enable efficient calculations. In particular, the selected frequencies may be chosen so that there is a known relationship between the frequencies. This relationship may be derived from Chebyshev polynomials and also relates the chosen frequencies to a low frequency pattern.

Abstract: The invention is a computer implemented method, device, system, or article for reconstructing a surface of an object. In particular, the invention comprises estimating a non-convex hull signed distance function parameters from a data set of an object and evaluating the non-convex hull signed distance function on vertices of a volumetric mesh. The invention further comprises approximating the zero level set of the non-convex hull signed distance function by a polygonal mesh using an isosurface algorithm to provide surface reconstruction of an object.

Abstract: A method obtains the shape of a target by projecting and recording images of dual frequency fringe patterns. Locations in each projector image plane are encoded into the patterns and projected onto die target while images are recorded. The resulting images show the patterns superimposed onto the target. The images are decoded to recover relative phase values for the patterns primary and dual frequencies. The relative phases are unwrapped into absolute phases and converted back to projector image plane locations. The relation between camera pixels and decoded projector locations is saved as a correspondence image representing the measured shape of the target. Correspondence images with a geometric triangulation method create a 3D model of the target. Dual frequency hinge patterns have a low frequency embedded into a high frequency sinusoidal, both frequencies are recovered in closed form by the decoding method, thus, enabling direct phase unwrapping.

Abstract: A method that estimates the coordinates of the calibration points in the projector image plane using local homographies obtained from the imaging camera. First, a dense set of correspondences between projector and camera pixels is found by projecting onto the calibration object an identical pattern sequence as the one later projected when scanning the target, reusing most of the software components written for the scanning application. Second, the set of correspondences is used to compute a group of local homographies that allow projection back of any of the points in the calibration object onto the projector image plane with sub-pixel precision. In the end, the data projector is then calibrated as a normal camera.

Abstract: Some aspects include a virtual reality device configured to present to a user a virtual environment. The virtual reality device comprises a tracking device including at least one camera to acquire image data, the tracking device, when worn by the user, configured to determine a position associated with the user and a stereoscopic display device configured to display at least a portion of a representation of the virtual environment, wherein the representation of the virtual environment is based, at least in part, on the determined position associated with the user, wherein the display device and the tracking device are configured to be worn by the user.

Abstract: Some aspects include a virtual reality device configured to present to a user a virtual environment. The virtual reality device comprises a tracking device including at least one camera to acquire image data, the tracking device, when worn by the user, configured to determine a position associated with the user and a stereoscopic display device configured to display at least a portion of a representation of the virtual environment, wherein the representation of the virtual environment is based, at least in part, on the determined position associated with the user, wherein the display device and the tracking device are configured to be worn by the user.

Abstract: A system and method to capture the surface geometry a three-dimensional object in a scene using unsynchronized structured lighting is disclosed. The method and system includes a pattern projector configured and arranged to project a sequence of image patterns onto the scene at a pattern frame rate, a camera configured and arranged to capture a sequence of unsynchronized image patterns of the scene at an image capture rate, and a processor configured and arranged to synthesize a sequence of synchronized image frames from the unsynchronized image patterns of the scene. Each of the synchronized image frames corresponds to one image pattern of the sequence of image patterns.

Abstract: A method obtains the shape of a target by projecting and recording images of dual frequency fringe patterns. Locations in each projector image plane are encoded into the patterns and projected onto die target while images are recorded. The resulting images show the patterns superimposed onto the target. The images are decoded to recover relative phase values for the patterns primary and dual frequencies. The relative phases are unwrapped into absolute phases and converted back to projector image plane locations. The relation between camera pixels and decoded projector locations is saved as a correspondence image representing the measured shape of the target. Correspondence images with a geometric triangulation method create a 3D model of the target. Dual frequency hinge patterns have a low frequency embedded into a high frequency sinusoidal, both frequencies are recovered in closed form by the decoding method, thus, enabling direct phase unwrapping.

Abstract: The invention is a computer implemented method, device, system, or article for reconstructing a surface of an object. In particular, the invention comprises estimating a non-convex hull signed distance function parameters from a data set of an object and evaluating the non-convex hull signed distance function on vertices of a volumetric mesh. The invention further comprises approximating the zero level set of the non-convex hull signed distance function by a polygonal mesh using an isosurface algorithm to provide surface reconstruction of an object.