Abstract: A method and apparatus for rendering textured spheres and spherical environment maps. The method of the present invention provides for real time rotation of a textured sphere and panning of the view into a spherical environment map, along multiple axes without the need for special rendering hardware. A two-level indexing scheme for accessing pixel data in a texture map, is used to identify shading values for pixels in a display window. The two-level indexing scheme is comprised of a screen look-up table and a parametric look-up table. The screen look-up table has the dimensions of the display window, whereas the parametric look-up table has the dimensions of the parametric spherical environment map (wherein the pixel addresses are rotated 90 degrees from the origin).

Abstract: Each one of three different, separate pixel density converters, which are alternative embodiments, operates upon an electrical signal representing successive pixels of an image. The first pixel density signal converter repeats an integration process by adding together multi-valued data representing intensity levels of two adjacent pixels, dividing by two, then repeating for such already integrated pixels to integrate a fixed number of pixels into one pixel, converting the result to a binary signal, the conversion comprising comparing the represented pixel intensity value to a fixed threshold value, and then transmitting a succession of such signals representing a plurality of adjacent data-reduced pixels. The second pixel density converter achieves comparable data reduction in a transmitted signal upon a basis of adding together a fixed number of pixels, more than two, dividing by the fixed number and performing a similar binary conversion.

Abstract: A method and apparatus of the alternately displaying two separate data entry views of an electronic mail object. A first data entry view graphically displays a visual metaphor of at least one sheet of note paper partially overlying an envelope, with only a portion of the envelope visible in the display. A second data entry view graphically displays a visual metaphor of an envelope overlying a portion of at least one sheet of note paper, with only a portion of the sheet of note paper visible in the display. In either view, the overlying displayed sheet of note paper or envelope is active for the entry of message text or destination information, respectively, while the partially displayed envelope or sheet of note paper is inactive to such data entry.

Abstract: A data processing system executes a spreadsheet program that supports callbacks from dynamic-link libraries. The dynamic-link libraries may callback into the spreadsheet program through an entry point provided in the spreadsheet program. These callbacks allow execution of spreadsheet program functions and commands from within the dynamic-link library. The ability to callback to the spreadsheet program from the dynamic-link library results in substantial savings in time and memory space.

Abstract: The virtual reality imaging system takes a multidimensional space that contains real world objects and phenomena, be they static or dynamic in nature, and enables a user to define a point and/or a path through this multidimensional space. The apparatus then displays the view to the user that would be seen from the point and/or path through the multidimensional space. This view is filtered through user definable characteristics that refine the real world phenomena and objects to a perspective that is of interest to the user. This filtered view presents the user with a virtual view of the reality contained within this multidimensional space, which virtual reality presents data to the user of only objects, views and phenomena that are of particular interest to the user.

Abstract: A method and system for the automatic alteration of a display of multiple user selectable menu options. A counter is associated with each user selectable menu option. The counter associated with a user selectable menu option is then incremented in response to each selection by a user of the user selectable menu option. The display of the user selectable menu option is automatically altered in response to a state of the associated counter.

Abstract: When processing an image it is often necessary to combine parts of its matrix mathematically, e.g. to multiply a part of this matrix with a given weighting function. In this context scalar products of vectors are important operations. The invention provides a coding procedure wherein two of the elements of two vectors are transformed to one encoded element, respectively, and are then stored. This has the result that the calculation of the scalar product requires two encoding operations of the elements and one multiplication of the encoded elements. When calculating another scalar product with at least partly the same elements the encoding operations of a number of elements are already done and the stored encoded elements can be used. This has the consequence that the calculation of this other scalar product requires at least partly no encoding operations but only multiplications of the stored encoded elements.

Abstract: A method for visualizing vector fields uses texture mapping for the vectors to create an animated vector field. Vectors are textured with one dimensional texture maps composed of alternating visible and invisible segments. Successively applied texture maps differ from each other in order to create a moving line effect on the vectors being visualized. A fading effect is further provided by varying the intensity of the visible segments.

Abstract: A process for producing a compressed image of a color picture. The color picture is optically scanned to obtain an array of optical parameters representing the basic colors at each coordinate point of the picture which are then converted into digital values. From such digital values, a selection is made of sets of data values representing a series of elements of the picture having discontinuities therein. A model is formulated for each of the elements having a first component containing all of the discontinuities and a second component representing the differentiable content of the elements. The second component is represented by a Taylor polynomial having a selected polynomial degree of at least 2. A maximum allowable error is then selected. The coefficients of the polynomials of the second component are calculated at selected points of a grid with a grid pitch defined by a specified formula. A compressed color picture is derived from the data values constituting the compressed image.

Abstract: Soft-edge processing of a video color image is effected in accordance with a stylus nib pressure. Initially, a display circle unit is determined having center coordinance corresponding to display coordinance of a stylus and having a radius corresponding to a nib pressure of the nib stylus. A display region is set encompassing the display circle unit, the display region having a plurality of pixels. A distance from each pixel located outside the circle unit within the display region to the circle unit is determined. This distance is then used as the basis for determining a Z value of the pixel which is indicative of the relative illumination of the pixel to effect soft-edge processing of the image.

Abstract: An interactive audiovisual work for telling a story includes a story element selector for selecting one of a plurality of differing actuatable story elements to be active, a character selector for selecting one of a plurality of differing actuatable characters to be active, and an identifier, active after a story element is selected, for identifying the character intended to be selected to be active at a given time according to the story. A microprocessor, responsive to the story element selector, the character selector and the character identifier, causes the selected character to speak a first-level message associated with the selected story element if the selected character and the identified character are the same, and a second-level message associated with the selected character otherwise, the first-level message being more specific and closely related to the selected story element than the second-level message.

Abstract: This invention relates to improvements in so-called "virtual reality" computer systems. The display system described enables the effective integration of computer generated images and real, naturally occurring images in the visual display units which provide the user with his entire visual stimulation. Areas of the user's notional field of view where computer-generated imagery is required (for example the cockpit canopy in an aircraft flight simulator) are coloured with a predetermined colour or intensity. Two video cameras are provided, each of which is mounted so that its field of view corresponds to a respective one of the notional fields of view of the user's eyes. The signals from the video cameras are analysed to determine the presence of the predetermined colour or intensity, thereby giving an indication that a computer generated image is required for that part of the video camera's field of view.

Abstract: A method and system for creating objects in a computer system having a display screen and a device for manipulating objects on the screen. The method includes displaying an object dispenser icon on the screen and a dispensable object mini-icon on the object dispenser icon. Objects may be created by dragging dispensable object icons out of the object dispenser icon, or by opening the dispensable object mini-icon. The objects dispensed by the dispenser may be modified by opening the object dispenser icon or by "dropping" a modified object icon on the dispenser icon. The dispenser icon may be moved about the display screen.

Abstract: A method is provided for writing directly to a frame buffer which provides signals to an output display of a computer system. The computer system has a first processor running a window management program controlling the furnishing of data in a first format to the frame buffer, and a second processor running application programs in a second format for display. A signal is provided from the second processor to the window management program indicating that an application program running on the second processor has information to be displayed. Then a window is set up for the display of the application program running on the second processor under control of the window management program. The second processor is signaled that the window exists and provided information regarding the position and clipping of the window.

Abstract: An apparatus and method for reproducing the color of blended colorants on an electronic display such as a cathode ray tube, liquid crystal display or other type of electronic device that utilizes RGB values. Predictions of blended colorants on or in substrates can be made from XYZ measurements of samples prepared with no colorants, one colorant, and pairs of colorants. The calculation method uses light absorption, light scattering, and light absorption blend coefficients. An image digitizer can be used to obtain XYZ values from samples. Furthermore, image digitizer RGB values are converted into XYZ values with a non-linear model using a simple method. Furthermore, the above process to generate XYZ values from image digitizer RGB values can be used to generate RGB values from XYZ values for electronic display.

Abstract: The method of this invention simulates a 16-bit color composite satellite picture upon an 8-bit color display system, a simulated picture being of substantially equal quality as a 16-bit picture, a simulated picture can be placed on a personal computer system or workstation having an 8-bit color display system. The two 8-bit images for creating the 16-bit color picture are combined in a unique manner so that a resulting 8-bit color composite picture is presented on the 8-bit color display system. The 8-bit picture produced generally has greater contrast than the picture produced on the 16 bit system.

Abstract: A parametric height-field ray-tracing process facilitates the construction of a perspective view display for terrain visualization by employing a map providing data in the form of a height field and wherein, prior to initiation of a ray tracing program, the set of voxels of the height field is transformed into a set of cones of empty space opening upwardly wherein the location of the vertex of each cone is near the height of the corresponding voxel. Each cone opens to a maximum cone angle which avoids intersection between the surface of the cone and vertical perturbations of the terrain such as buildings or hills. Ray tracing is conducted by calculating intercepts of a ray with surfaces of a succession of cones wherein the next cone of the succession is obtained by selecting the cone having a vertex beneath the location of the previous intersection. This procedure reduces greatly the number of computations required for a ray-tracing program.

Abstract: A method is provided for distinguishing nonconvex polygons from complex polygons. The present invention compares the edges of a polygon for self intersection points. Initially, "base" and "compare" edges are designated and bounding boxes for each of these edges are determined. The bounding boxes are then compared and if they intersect the edges may have points in common, whereas if no intersection occurs, then there are no common points and the edges are incremented and a comparison of other edges occurs. If it is determined that bounding boxes intersect, the intersection point for the edges under consideration is determined. If this intersection point lies within both bounding boxes, then the polygon is complex and the test ends. However, if the intersection point is outside either bounding box, then the edges are incremented and processing continues until all relevant edges have been considered.

Abstract: A two- or three-dimensional image of an object is first input into a computer system. An operator may then define one or more regions of the image for application of surface texture. A two-dimensional image of a surface texture is also input into the computer system. A polygonal area or patch, such as a rectangle, of the surface texture is then defined by the operator. A corresponding patch on the object image, which need not have the same shape or orientation as the patch on the texture image, is also defined by the operator. The patches on the texture image and on the object image need not be contiguous, adjacent or uniform. The object patch is assumed to be a perspective view of the corresponding texture patch, and a three-dimensional mapping function from the texture patch to the object patch is calculated.

Abstract: A method of synthesizing a real image and a computer graphic (CG) having a complex shape in which the normal vector of each of two adjacent planes of a rectangular parallelepiped CG circumscribed about the CG having a complex shape is determined from the coordinates of six vertices representing the two planes on the basis of a real image of a rectangular parallelepiped, and parameters for three-dimensional rotational transformation of the rectangular parallelepiped CG required for synthesis are determined on the basis of the normal vectors. A CG having a complex shape for synthesis is produced by rotational transformation thereof on the basis of the parameters, and the CG having a complex shape thus produced is synthesized on the real image.