Abstract: Methods and systems for utilizing a parallel conversational thread during a remote collaboration are described. In one embodiment, a managing entity is utilized to establish a first communications path for a remote collaboration of at least two parties. Then, a request for a parallel conversation is received from at least one of the at least two parties during the remote collaboration. The managing entity then establishes a second communications path for the parallel conversation between the at least two parties. Wherein, the enabling of the parallel conversation on the second communications path is performed without inhibiting the first communications path, such that a portion of a first party can have a parallel conversation with a portion of a second party on the second communications path while the first communications path for the remote collaboration remains active.

Abstract: A method for real-time video communication. Specifically, one embodiment of the present invention discloses a method of video conferencing that captures a plurality of real-time video streams of a local participant from a plurality of sample viewpoints. From the plurality of video streams, a new view synthesis technique can be applied to generate a video image stream in real-time of the local participant rendered from a second location of a second participant with respect to a first location of the local participant in a coordinate space of a virtual environment. A change in either of the locations leads to the modifying of the video image stream, thereby enabling real-time video communication from the local participant to the second participant.

Abstract: A retractable camera apparatus is disclosed. Through the use of the apparatus in accordance with the present invention, a video teleconferencing environment can communicate, in real time, such personal features as gesture, expression and body language. The apparatus includes a housing portion, at least one arm portion coupled to the housing portion wherein the at least one arm portion is capable of being moved between a retracted position and a deployed position and at least one camera coupled to the at least one arm portion.

Abstract: A method of varying focus in a scene. Specifically, one embodiment of the present invention discloses a method for modeling a scene using a parametric texture map (PTM) under varying focus conditions of one or more dimensions: e.g., focus depth and depth of field. A dataset of photographs is obtained under separate focus conditions. Approximation of the dataset creates an associated PTM representation that is capable of generating scenes of the photographic scene under varying focus conditions anywhere within the range of focus conditions specified by the initial data set. In addition, extrapolation yields results outside the range of focus conditions.

Abstract: A method for real-time video communication. Specifically, one embodiment of the present invention discloses a method of video conferencing that captures a plurality of real-time video streams of a local participant from a plurality of sample viewpoints. From the plurality of video streams, a new view synthesis technique can be applied to generate a video image stream in real-time of the local participant rendered from a second location of a second participant with respect to a first location of the local participant in a coordinate space of a virtual environment. A change in either of the locations leads to the modifying of the video image stream, thereby enabling real-time video communication from the local participant to the second participant.

Abstract: A graphics system that enhances shape perception. The presently preferred embodiment of the system utilizes the mathematical machinery of parametric texture maps. In general, parametric texture maps allow the graphics system to render surface features of a 3D object in a manner that is direction dependent but without the time consuming and expensive calculations involved in the evaluation of lighting equations on a per pixel basis. A parametric texture map holds a set of parameters that define a surface structure in a manner in which the appearance of the surface structure varies in response to a direction vector. The direction vector may be any user-defined vector including a light source vector or a half-angle vector. The parameters are those of a predetermined equation, the evaluation of which does not involve vector calculations. The equation may take any form including a polynomial equation or a non-polynomial equation. The graphic system renders a polygon with the surface structure using the equation.

Abstract: A method of varying focus in a scene. Specifically, one embodiment of the present invention discloses a method for modeling a scene using a parametric texture map (PTM) under varying focus conditions of one or more dimensions: e.g., focus depth and depth of field. A dataset of photographs is obtained under separate focus conditions. Approximation of the dataset creates an associated PTM representation that is capable of generating scenes of the photographic scene under varying focus conditions anywhere within the range of focus conditions specified by the initial data set. In addition, extrapolation yields results outside the range of focus conditions.

Abstract: A graphics system that employs parametric texture maps. The graphics system renders surface features of a 3D object in a manner that is direction dependent but without the time consuming and expensive calculations involved in the evaluation of lighting equations on a per pixel basis. A parametric texture map holds a set of parameters that define a surface structure in a manner in which the appearance of the surface structure varies in response to a direction vector. The direction vector may be any user-defined vector including a light source vector or a half-angle vector. The parameters are those of a predetermined equation, the evaluation of which does not involve vector calculations. The equation may take any form including a polynomial equation or a non-polynomial equation. The graphic system renders a polygon with the surface structure using the equation.

Abstract: A method of generating a three-dimensional model of a scene from a plurality of photographs of the scene. The method includes voxels in an interior region and an exterior region of the scene in question and then examines the voxels to determine if they are empty or part of the objects in the scene. The interior region is divided into a plurality of interior voxels, that are preferably of the same size. The exterior region surrounds the interior space and is divided into exterior voxels having different sizes. The size of the exterior voxels increases as a function of the distance between the voxel and the interior region. The voxels that are furthest from the interior region are preferably infinite in size.

Abstract: A graphics system that employs parametric texture maps. The graphics system renders surface features of a 3D object in a manner that is direction dependent but without the time consuming and expensive calculations involved in the evaluation of lighting equations on a per pixel basis. A parametric texture map holds a set of parameters that define a surface structure in a manner in which the appearance of the surface structure varies in response to a direction vector. The direction vector may be any user-defined vector including a light source vector or a half-angle vector. The parameters are those of a predetermined equation, the evaluation of which does not involve vector calculations. The equation may take any form including a polynomial equation or a non-polynomial equation. The graphic system renders a polygon with the surface structure using the equation.

Abstract: Methods and apparatus are provided for volumemetric scene reconstruction. Given a set of images of the scene taken from arbitrary but known locations, a 3D model of the scene is reconstructed. Voxels are used to model the scene and exploit the fact that surface points in the scene, and the voxels that represent them, project to consistent colors in the input images. Input cameras may be placed at arbitrary locations in and around the scene. When checking the color consistency of a voxel, the entire set of images from which the voxel is visible is used. A GVC algorithm utilizes item buffers which contain, for each pixel in each image, the ID of the closest voxel that projects onto to the pixel. A GVC-LDI algorithm uses layered depth images which store at each pixel location a list of all the surface voxels that project onto the pixel, sorted according to the distance of the voxel from the image's camera.

Abstract: A graphics system that renders surface features of 3D object in a manner that is direction dependent but without the time consuming and expensive calculations involved in the evaluation of lighting equations on a per pixel basis. The graphics system employs direction-dependent texture maps which hold parameters that define surface structures in a manner in which the appearance of a surface structure varies in response to a direction vector. The direction vector may be light source direction or view direction. The parameters are those of a predetermined polynomial equation the evaluation of which does not involve vector calculations.

Abstract: In order to solve the need for an accurate two-dimensional representation of a three-dimensional image, the invention provides an improved method and apparatus for processing voxel data which avoid the problem of color artifacts coming from zero opacity regions. The three-dimensional image is stored in a computer memory as a three-dimensional data array having object data values associated with sample points in a three-dimensional space. A central processing unit (CPU) processes the object data values to determine voxel colors C and voxel opacities &agr; for the plurality of sample points and then opacity weights the voxel colors to produce a set of opacity weighted colors {tilde over (C)}. Next, the voxel opacities &agr; and the opacity weighted colors {tilde over (C)} from each sample point are composited in a compositor to form the two-dimensional representation. Finally, a display unit visually displays the two-dimensional representation.

Abstract: A method and system for viewing three-dimensional data which corresponds to a structure that has been tracked throughout the three-dimensional data is disclosed. Typically, structures which require tracking so that they can be followed throughout three-dimensional data are non-planar and, therefore, very difficult to view. Initially, tracking data is obtained by tracking a structure through the three-dimensional data. After the structure has been tracked through the three-dimensional data, the structure is displayed on a monitor or display device such that the portion of the three-dimensional data which is pertinent to the tracked structure is distinguishable from other data. As a result, a user can readily and easily view the data associated with the tracked structure.

Abstract: A tracking technique which tracks a structure in three-dimensional data is disclosed. The tracking technique uses a geometric shape to model the structure to be tracked. Tracking is achieved by altering the orientation (and perhaps scale) of the geometric shape at a given three-dimensional point until it best fits the structure being tracked. Using this best fit information, a subsequent point within the structure being tracked can be identified. The tracking continues by thereafter altering the orientation (and perhaps scale) of the geometric shape at or near the subsequent point until a best fit is identified. The invention can be implemented as a digital filter, a tracking system or a method.

Abstract: An apparatus and method adapted for performing volume rendering is disclosed in which the object space is divided between a plurality of processing units. Each processing unit generates a view of the data which is restricted to a portion of the object space. The view so generated are then combined a plurality of compositing processors to form the view of the object.

Abstract: The view generated is the view of a three-dimensional object that would be obtained if the object in question consisted of a translucent material illuminated with a beam of parallel light is generated. The method utilizes a spatial-to-frequency domain transformation that substantially reduces the computational workload. Once the object representation in the frequency domain has been generated, the computational workload needed to generate a projection is significantly less than that needed in other methods.

Abstract: A graphics tablet is presented which has an x-y grid of wire traces embedded on it. Drive wires are coupled to the trace wires in both the x-direction and the y-direction. When a stylus is placed in contact with the graphics tablet, the location of a sector of the graphics tablet where the stylus contacts the graphics tablet may be determined by sequentially placing a signal on each drive wire and measuring the strength of the signal received by the stylus. The closer the stylus is to a particular trace, the stronger the signal which is received by the stylus from the drive wire coupled to that trace. The identity of a plurality of drive wires in the x-direction and a plurality of wires in the y-direction with the strongest received signal can be used to determine a unique address for the location of the sector of the graphics tablet where the stylus contacts the graphics tablet.