Microsoft Technology Licensing, LLC

Leland Stanford Junior University

Donald P Mitchell

John Carlton Platt

Steven Mark Drucker

J Turner Whitted

James Frederick Blinn

Michael David Marr

Bodin Dresevic

Patrick M Hanrahan

Claude Betrisey

Craig E Kolb

Kirk J Marple

Image data processing and image rendering methods and systems whereby images are displayed on display devices having pixels with separately controllable pixel sub-components. Image data, such as data encoded in a three-channel signal, is passed through a low-pass filter to remove frequencies higher than a selected cutoff frequency, which obtain samples from the color components of the signal that map spatially different image regions to individual pixel sub-components. It has been found that color aliasing effects can be significantly reduces at a cutoff frequency somewhat higher than the Nyquist frequency, while enhancing the spatial resolution of the image. The image data is then passed through sampling filters, A generalized set of filters includes nine filters, one for each combination of one color and one pixel sub-component. The filtering coefficients of the filters can be selected to optimize of approximate an optimization of an error metric, which represents the color and luminance errors perceived on the display device. In this manner, a desired balance between color accuracy and luminance accuracy can be obtained. The samples mapped to individual pixel sub-components are used to generate luminous intensity values for the displayed image.

Filtering image data to obtain samples mapped to pixel sub-components of a display device

Image data processing and image rendering methods and systems whereby images are displayed on display devices having pixels with separately controllable pixel sub-components. Image data, such as data encoded in a three-channel signal, is passed through a low-pass filter to remove frequencies higher than a selected cutoff frequency, which obtain samples from the color components of the signal that map spatially different image regions to individual pixel sub-components. It has been found that color aliasing effects can be significantly reduces at a cutoff frequency somewhat higher than the Nyquist frequency, while enhancing the spatial resolution of the image. The image data is then pass through sampling filters, A generalized set of filters includes nine filters, one for each combination of one color and one pixel sub-component. The filtering coefficients of the filters can be selected to optimize of approximate an optimization of an error metric, which represents the color and luminance errors perceived on the display device. In this manner, a desired balance between color accuracy and luminance accuracy can be obtained. The samples mapped to individual pixel sub-components are used to generate luminous intensity values for the displayed image.

Techniques for improving the resolution of images (either analog images, analytic images, or images having a higher resolution than that of a display device) to be rendered on patterned displays. In one aspect of the present invention, an overscaling or oversampling process may accept analytic character information, such as contours for example, and a scale factor or grid and overscale or oversample the analytic character information to produce an overscaled or oversampled image. The overscaled or oversampled image generated has a higher resolution than the display upon which the character is to be rendered. Displaced samples of the overscaled or oversampled image are then combined (or filtered). An analytic image, such as a line drawing for example, may be applied to the oversampling/overscaling process as was the case with the character analytic image. However, since the analytic image may have different units than that of the character analytic image, the scale factor applied may be different. Since an ultra resolution image is already &ldquo;digitized&rdquo;, that is, not merely mathematically expressed contours or lines between points, it may be applied directly to a process for combining displaced samples of the ultra-resolution image to generate another ultra-resolution image (or an image with sub-pixel information). The functionality of the overscaling/oversampling process and the processes for combining displaced samples may be combined into a single step analytic to digital sub-pixel resolution conversion process.

Methods apparatus and data structures for enhancing the resolution of images to be rendered on patterned display devices

A virtual world environment (VWE) employing a client-server architecture to organize data defining the VWE and objects contained therein in a system of distributed databases. An object in the VWE is one of four basic types including: an artifact, an avatar, a portal, and a room. A world database is maintained by a server computer and is the central storehouse for data defining the entire VWE. Each user has a client computer that is coupled in communication with the server computer. The client computer administers a local database defining at least a portion of the VWE. Each object that is affected by a change in another object is said to be in a bystander region of the other object. The local database maintained by the user's client computer is only updated by the server computer to include changes to the objects associated with the client computer (user) in the bystander region of the other object, i.e., changes evident to an object associated with the user. As a result, many more users can be supported by the server computer and data transmission over the network link between the server and client computers is minimized.

Virtual environment bystander updating in client server architecture

A collision of a moving object with another object in a 3D virtual world is efficiently determined in real time so that the technique is usable over a network. An object in the 3D virtual world is projected onto a 2D plane. The projection of the object is bounded by a two-sided edge cycle that is formed from a sequence of line segments having endpoints that are consecutively joined at an ordered series of vertices. One side, which is formed by a counterclockwise ordering of the line segments and their respective vertices, is characterized as 'front facing.' The other side is characterized as 'back facing.' Additionally, the front and back facing characterization of a side of the edge cycle is determined by the disposition of the moving object, i.e., the closest side of the edge cycle to the moving object is its back facing side. A path line segment is developed for the projection of a path of a moving object onto the 2D plane, and a path line equation is determined for the path line segment. The path line equation is employed to identify any positive to negative sign transition between consecutive vertices of a front facing line segment of the edge cycle. An edge cycle line equation is then evaluated with the endpoints of the path line segment for the moving object to determine if the path line segment has intersected the line segment of the edge cycle during a particular time period.

Edge cycle collision detection in graphics environment

A physical camera is modeled to render an image in a computer graphics system. When given the manufacturer's specifications of the physical camera's lenses, including the dimensions and indices of refraction of its lenses, stops, and shutter characteristics, the location of the film surface relative to the lens system, and the orientation of the camera within the scene, the invention accurately and efficiently mimics the physical principles of image formation creating an image which approximates an image produced by the physical camera. The procedure comprises four main elements: (1) the geometric relationships between the lens system, object, and film plane are modeled by precise placement and movement of lens elements, (2) image geometry is computed by using principles of geometric optics, (3) an exit pupil is calculated in order to define a region for efficiently sampling rays, (4) the image irradiance, or exposure at a pixel, is computed according to radiometric principles.

Camera simulation system

Geometric data for a three-dimensional surface are compressed in regard to the data representing the continuity between triangles in a mesh that represents the three-dimensional surface. The geometric data include information defining the vertices of the triangles comprising the mesh, an indication of the triangle faces, and corner normals to each of the vertices shared by triangles having a common vertex, which indicates the continuity or discontinuity between adjacent triangles of the surface. Vertex rotation continuity (VRC) data are determined for each vertex shared by adjacent triangles, indicating whether the transition between the adjacent triangles is continuous or discontinuous. Further, a dihedral angle between each pair of adjacent triangles is determined and associated with the VRC bit. The VRC data are sorted by the associated dihedral angles, enabling an optimal dihedral angle to be selected. The optimal dihedral angle is chosen so as to minimize the number of errors in predicting the nature of the transition between adjacent triangles based on the dihedral angle between the adjacent triangle. Next, exception data are generated by comparing the dihedral angle for each pair of adjacent triangles to the optimal dihedral angle to predict a VRC bit, and noting any errors within the exception data. The exception data are encoded to further reduce the size of the compressed data used to represent the three-dimensional surface. The compressed data require less space for storage and are more efficiently transmitted to a remote site.

Growing community of inventors

Bellevue, WA, United States of America

Donald P Mitchell