A computer-implemented method of image generation that makes efficient use of reprojective techniques to reduce the cost of image generation. The method employs a technique of primitive reprojection in which convex graphics primitives are the reprojected elements. The visibility of elements known to be visible in a previous frame is first determined by transformation and depth-comparison rasterization of these elements. Regions of the image that may contain newly visible elements are located by occlusion-exposure transitions in the depth buffer and from incremental view volume motion. In these regions a depth-prioritized, data-access method of visible surface determination, spatial-subdivision ray casting, is employed to identify newly visible primitives which are added to the list of previously visible primitives for rasterization. The method employs a system of classifying objects based on their dynamic occlusive properties to increase the accuracy, efficiency and versatility of the reprojective approach. Because the method employs a hybrid approach to visible surface determination in which newly visible primitives are identified for each frame it can be implemented as a graphics server employing an efficient on-demand, progressive geometry transmission protocol for client-server image generation. This client-server system employs a method of visibility event encoding in which data representing newly visible and newly invisible primitives for each frame are transmitted to a client unit which is a conventional graphics display system. The visibility event codec method can also be used to encode and store information representing a computer animation for later interactive playback.

System and method of image generation and encoding using primitive reprojection

A computer implemented method of image generation that employs adaptive, progressive, perception-based spatio-temporal importance sampling to reduce the cost of image generation. The method uses an adaptive approach to sampling which employs refinement criteria based on specific spatio-temporal limits of human vision. By using these refinement criteria the method produces an image with a spatio-temporal structure that is closely matched to the spatio-temporal limits of human vision. Using one sampling criteria the spatial sampling density is adjusted in proportion to the sampled region's exposure duration in a manner that substantially reflects the visual systems's increase in acuity as a function of exposure time. Using other criteria the spatial and temporal sampling frequencies of a region of the image stream are adjusted based on the measured or estimated retinal velocity of the sampled element in a manner that substantially reflects both dynamic visual acuity limits of vision and the critical temporal sampling frequency for the perception of smooth motion. The method includes image parallel, shared-memory multiprocessor implementations based on sample reprojection and primitive reprojection, the latter using a technique of adaptive rasterization. In these implementations the natural temporal image coherence and temporal visibility coherence of the image stream produce a temporal locality of data reference that enhances performance of the system. Because temporal image coherence and temporal visibility coherence increase the spatial resolving performance of the human visual system, the performance of the present method parallels the performance of human vision making performance degradations relatively invisible to the user.

System and method of perception-based image generation and encoding

There is disclosed a system which permits an automobile driver to control electrical devices installed on an automobile by moving his or her pupils and mouth intentionally. The system includes a TV camera, a light, a first microprocessor which controls the electrical devices according to the changes in the shape of the driver's mouth, a second microprocessor for performing various arithmetic operations, and memories. Reference values have been previously assigned to various elements of the driver's face and stored in one of the memories. The second microprocessor normalizes the distances between the elements of the face with the distance between the pupils of the eyes and compares the normalized distances with the reference values to calculate the degrees of similarity of the elements.

System for recognizing image

An object-oriented display system which displays an image of a graphical object on a display device, the position at which the object is displayed being a function of the position from which a viewer views the display device so as to simulate an interactive, three-dimensional viewing environment. An object-oriented display system, in which the highest discernible level of data in the frame buffer is an object with preserved association of pixels to the object allows dynamic selection of view. View position data may be employed on-the-fly to dynamically determine display from an arbitrary view position. Object data storage in tile format allows for rapid and simplified display generation.

Interactive display apparatus and method with viewer position compensation

Technology is described for a peripheral display for use with a near-eye display device. The peripheral display is positioned by a near-eye support structure of the near-eye display device for directing a visual representation of an object towards a side of an eye area associated with the near-eye display device. The peripheral display has a lower resolution than a resolution of a front display of the near-eye display device. The peripheral display may include a Fresnel structure. The peripheral display may be used for augmented reality, virtual reality and enhanced vision applications.

Peripheral display for a near-eye display device

Visual system (37) for providing high detail, high resolution imagery anywhere a trainee is looking throughout a wide field of view. An image generation system (38) of visual system (37) accepts inputs from a helmet mounted oculometer system (30) which determines a trainee's instantaneous eye line-of-sight. The image generation system (38) provides a foveal view of high detail, high resolution imagery at the eye line-of-sight. The foveal view is projected on a screen (46) by a foveal projection system (40). The image generation system (38) further provides a peripheral view of low detail, low resolution imagery that is projected on screen (46) by a peripheral projection system (42). The foveal view is merged with the peripheral view by a merge electronics system (44).

Eye line-of-sight responsive wide angle visual system

A simulated view on a viewing surface of a raster scan television display of a changeable illuminated area located on a plane surface is provided. The source of illumination is a cone of light whose apex can be located at any distance from an eyepoint and the plane surface and whose conical surface intersects the plane surface creating the illuminated area. Electronic components determine when a line of sight from the eyepoint through the viewing surface intersects the illuminated area. For each line of sight intersection point lying within the illuminated area, a corresponding illumination is created on the viewing surface.

Simulation technique for generating a visual representation of an illuminated area

Two video signals are precisely gain balanced so that one video signal may be inserted, unnoticeably, into a display derived from the first of the two video signals. To this end, a strobe is generated as the inset video signal is initiated. Both the inset video and the display video signals are sampled at the time said strobe is generated. A difference signal is derived from both samples and the gain of the inset video channel is adjusted in accord with the magnitude of that difference signal in a manner so as to minimize that magnitude.

Precision gain balance of two video sources for a single display

An improved multiple channel, wide-angle visual image projection system producing a movable displayed image. The system permits the use of two or more light projectors for high resolution wide-angle image display while eliminating image abutment and alignment problems. The system forms a composite image from two or more projectors in a strategically aligned prism array, the composite image being optically transferred to a single wide-angle projection lens, gimballed in azimuth and elevation, through a pair of movable servo-driven prisms for projection onto a two-dimensional screen. The projection system is especially suited for use in an area-of-interest, helmet-slaved visual display in a flight simulator.

Wide angle area-of-interest visual image projection system

The invention is a variable gain non-Lambertian screen surface (12) for employment in a visual display system. The screen surface provides constant image brightness, independent of changes in viewing angle (22). It is therefore suitable for off-axis viewing. The screen gain continuously varies from a magnitude of one to infinity at different portions on the screen surface in such a manner that the equivalent gain preceived by an off-axis viewer (16) corresponds to the viewer perceiving constant image brightness, independent of changes in the viewing angle.

David L. Peters

Papers

Eye line-of-sight responsive wide angle visual system

Simulation technique for generating a visual representation of an illuminated area

Precision gain balance of two video sources for a single display

Wide angle area-of-interest visual image projection system

Variable gain screen permitting off-axis viewing with image brightness remaining constant