Abstract: Controlling the attributes (such as transparency) of volume-rendered images via a window/level mechanism when the images are displayed is disclosed. A volume-rendered image includes a set of voxel data representing an object. The set of voxel data has a range of voxel values, and each voxel datum (or voxel) has at least a voxel value and an attribute value (such as a transparency value). In one embodiment, a computerized system includes a characteristic selector, a level point and window set, and a viewer. The characteristic selector permits a user to select a characteristic to control an attribute of the set of voxel data, such as transparency. The level point and window set permits the user to set the level point and the window within the range of voxel values, where the window is centered at the level point and the characteristic is at least applicable within the window.

Abstract: Labeling objects on a computerized map in an efficient manner while avoiding collisions with both more and less important objects. A first list contains objects to be labeled on the computerized map, the objects being both points and non-points. Each of the objects in the first list has a label selection priority. A second list contains the a collection of objects from the first list having the lowest label selection priority. The system can draw each object in the first list to the computerized map in ascending order of label selection priority. As each object is drawn, the system labels the object with a label while avoiding collisions between the label and objects in the second list having a higher label selection priority than the object.

Abstract: A scheme that generates image processing source code for custom applications automatically by using structured image (SI) technology in a way that takes advantage of the unbound and incomplete features of SI. Resulting custom applications developed by this method can be defined and converted to running source code in minutes, or shipped to a co-user of the system in a compact portable form for remote code generation.Nested sub-component references and associated image processing operations necessary to generate an output raster image are obtained from a structured image template. Image processing operations and the order of said operations within an image processing definition are stored within the structured image definition. Unbound structured image references to undefined component objects and incomplete structured image references to image processing operations and parameters not explicitly defined within said structured image are input options.

Abstract: Starting with a solid model of a 3D object, an accurate skeleton is produced by minimizing internal and edge errors of an initial approximate skeleton. To produce the initial approximate skeleton, the boundary of the solid is densely sampled to obtain a set of surface data points. Delaunay triangulation is performed on the surface data points and exterior and spurious tetrahedra are removed, leaving substantially interior tetrahedra. Circumspheres are constructed that enclose the tetrahedra, and the centers of the circumspheres are connected based on tetrahedra adjacency, to form a Voronoi diagram. Closed Voronoi cells are identified comprising the initial approximate skeleton. The position of skeleton interior vertices are then adjusted to minimize their error, producing a refined polygonal approximation of the skeleton interior geometry. Positions of the skeleton edge vertices are adjusted to minimize the edge error, yielding an accurate polygonal approximation of the skeleton.

Abstract: A system for reading texture data from a memory without need to use a cache unit in such a manner that the read speed is not affected by the size of the memory, wherein a memory address is supplied to a memory address comparing unit, a memory address comparing unit compares the memory address of the current pixel and the memory address of the immediately preceding adjacent pixel, the compared result being supplied as information to a compared result storing unit which stores the information. A memory accessing unit receives a memory address different from the memory address of the adjacent pixel and reads texture data the corresponding address in a memory, the texture data being stored in a texture data storing unit. A texture data restructuring unit reads texture data from the texture data storing unit corresponding to the information read from the compared result storing unit and restructures the texture data accordingly.

Abstract: A method and system for generating symbols in real time on a display screen. The method and system can be applied to generating symbols for assisting in aircraft piloting and navigation. For the plotted lines generated on a matrix screen such as a liquid crystal display screen, the visual appearance deteriorates since the eye is sensitive to the steps produced by the matrix array. To improve the appearance, the plotted lines are widened and they are modulated in luminosity and in color. This is done by replacing each point of a theoretical plotted line by a micro-zone of N.times.M points modulated in intensity according to a table of instructed-value coefficients. Coefficients are computed for each point of the widened plotted line on the basis of this table and on the basis of coefficients previously computed for the same points.

Abstract: A computer-implemented method and apparatus for reparameterizing a parametric function representing an animation feature in an animation system where the parametric function is represented by a curve having unequal arc-length per unit parameter. The system samples at intervals of the parameter along the length of the curve and then calculates the arc-length over each interval. Thereafter, one or more differentiable curves are fitted to the parameter, arc-length pairs.

Abstract: A computer-implemented method modifies a curve in response to a user action through a graphical user interface in the computer system, with the curve being defined by control points. Each of the control points is identified in response to user input as a fixed control point, a selected control point, or a free control point. A displacement of selected points is received, and a free slope control point of the curve is mapped to a point Tp on a line t. An interpolation curve IC(t) is defined on the line t, and a point Tp is projected to the value of the interpolation curve IC(t) at t equals Tp to find a scale factor. The scale factor is multiplied by the displacement of the selected points to determine the displacement of the free control point. A computer-implemented graphical user interface method creates a Bezier curve segment on a display in a computer system. A selection of a first segment end point is received through a graphical user interface in the computer system.

Abstract: A technique and system to enhance the synthesis of solid models from two drawings. The two-dimensional coordinates of a vertex are extracted in each of a top view and a front view and, if their x-coordinates are equal to each other, the combination of their Y-coordinate values is determined to be the two-dimensional coordinates of a candidate vertex in a side view. Then, candidate line segments for the side view are extracted from the line segments connecting two candidate vertices. The process does not extract those line segments for which no corresponding line segment exists in the top and front views and those line segments for which corresponding horizontal or vertical line segments exist in the top and front views, but which are not horizontal or vertical in the side view.

Abstract: The current invention provides both location and magnitude representations in a geographic information system (GIS) environment. To indicate the locations, symbols are plotted on a map. To indicate magnitude, repeated symbols are stacked on top of each other. The higher the stack of symbols, the bigger the magnitude. The number of symbols to be stacked will be proportional to any scaling scheme. The position or coordinate of the symbols to be stacked will be based on any mathematical function. The size the symbols to be stacked will be based on any mathematical function. The color of the symbols to be stacked will be based on any function applicable to color. The shape of the symbols to be stacked will be based on any function applicable to shape or object, or according to a look-up table.

Abstract: Distortion of normal vectors when approximating shape data with normal vectors is restrained. At step ST1, original polygon date is input. At step ST2, each edge is evaluated for performing removal of an edge. At step ST3, the evaluation values are sorted by magnitude and the edge having the minimum value is selected. At step ST4, the edge having the minimum evaluation value selected at step ST3 is removed. At step ST5, the position of vertices remaining after removal of the edge is decided. At step ST6, a normal vector which has become unnecessary on removal of the edge is removed and the remaining normal vectors are changed. At step ST7, an approximated model is drawn. The processing from steps ST2 to ST6 is repeatedly executed in accordance with a desired precision.

Abstract: A method and apparatus for simultaneously displaying numerical data on contribution of various parts to a whole by breaking up the data into the different parts that contributed to the whole and assigning a different color to each. Then the amount of each of these parts is determined and the measurements are plotted by combining the colors into a hue, where the color of the hue represents the relative contribution of the each part for each piece of numerical data.

Abstract: A solid model is constructed from surface point data that represent layers of an object. The model is represented as the level set of an implicit function that is fitted to the surface point data. In the two-dimensional application of the technique, a Delaunay triangulation is performed for each layer. In this step, surface points are connected to form Delaunay triangles; the data points are the vertices of the Delaunay triangles. A circumcircle is then created around each Delaunay triangle, passing through the three vertices of the triangle. To decimate the circumcircle data, overlapping circumspheres are merged according to a merging criterion. A pseudo-union of implicit functions for the reduced number of circumcircles provides an initial implicit function for the layer. Errors in the implicit function are substantially reduced by optimizing the position and/or radii of the circumcircles.

Abstract: Described is a simple and robust method and system for generating new views from arbitrary camera positions without depth information or feature matching, simply by combining and resampling the available images. This technique interprets input images as two-dimensional slices of a four dimensional function--the light field. This function completely characterizes the flow of light through unobstructed space in a static scene with fixed illumination. A sampled representation for light fields allows for both efficient creation and display of inward and outward looking views. Light fields may be created from large arrays of both rendered and digitized image. The latter are acquired with a video camera mounted on a computer-controlled gantry. Once a light field has been created, new views may be constructed in real time by extracting slices in appropriate directions.

Abstract: The present invention provides a unified, automated approach to 3D object interpolation and 3D morphing based on a geometric descriptor known as the skeleton. The skeleton of an object consists of the closure of the set of points minimally equidistant from two points on the object's boundary. An "intermediate 3D object" between a pair of two other 3D objects is obtained as the (trimmed) skeleton of the symmetric difference of the pair of objects. By applying this process recursively, any desired number of intermediate 3D objects between a first and a last object may be obtained to produce a discrete 3D morph. A discrete morph can be thought of as an animation starting from the initial object and ending with the final object after a given number of the intermediate objects. Alternatively, the skeleton is used to identify corresponding points on the surfaces of the objects. Interpolation between the location of the corresponding points is then used to determine a continuum of intermediate 3D objects.

Abstract: A series of autostereograms of a three dimensional scene is displayed. The apparent depth of a reference surface in the scene is varied from one autostereogram of the series to another. A human viewer looks at the autostereograms, adjusting the eyes to viewing of a surface at an arbitrary depth. When the apparent depth of the surface corresponds to the arbitrary depth, the human viewer will perceive a three dimensional effect and signal this with a feedback signal. Upon detection of the feedback signal a further autostereogram is displayed instead of the series of autostereograms. The further autostereogram displays of a further three dimensional scene containing a further reference surface, in which a further apparent depth of the further reference surface is selected according to the apparent depth for which the viewer feedback was received. Thus the further apparent depth is adjusted to the setting of the eyes of the human viewer.

Abstract: A virtual object display apparatus displays an object moved in three-dimensional virtual space. A key frame memory section previously stores move data of each part of the object by unit of action of the object's movement in three-dimensional virtual space. A swing calculation section calculates the change of a basis point of the object by unit of action according to the move data of each part of the object. A display position set section calculates the change of display position corresponding to the change of the basis point in three-dimensional virtual space by unit of action. A display section displays the object movement in three-dimensional virtual space according to the display position by unit of action.

Abstract: A computerized two-dimensional illustration system composes an image of a scene with layered synthetic graphics filters or lenses. The scene is defined by an ordered list of shapes. Some of the shapes in the ordered list of shapes are lenses. Each lens is a shape that has a fill color which is an operator rather than a constant. The operator of a selected lens performs a filtering function on the shapes ordered below it in the list of shapes. To compose a selected lens in the scene, the system first computes an under-list of shapes for the selected lens. The under-list of shapes is used to identify those shapes in the ordered list of shapes to which the filtering function of the selected lens may apply. Depending on the filtering function of a lens, the lens composes in either a back-to-front order or a front-to-back order. A lens composes in a back-to-front order by freezing lenses in the under-list before applying the filtering function of the lens to shapes in the under-list.

Abstract: An image forming apparatus which comprises image inputter for inputting an image, information inputter for inputting information to be added to the image, image producer for producing an output pixel corresponding to the image inputted by the image inputter using a line screen whose line width is changed depending on desired density of the output pixel, position changer for changing a position of the output pixel to be produced in accordance with the information inputted by the information inputter in a line width direction of the line screen within the width of the screen in a process of producing the output pixel corresponding to the inputted image by the image producer, and controller for controlling the image producer to produce the output pixel in the position changed by the position changer using the line screen.

Abstract: A system, method and computer program are provided for a virtual three-dimensional workspace wherein dependent upon the position of the viewpoint with respect to a particular object, that object may be a functional interactive object with the user at the viewpoint if the virtual distance of the viewpoint to the object is within a certain specified distance. However, if the viewpoint moves beyond this distance, then the object is rendered noninteractive and becomes part of an aggregate object at the next distance level. In forming this aggregate object, the selected object joins a plurality of other noninteractive objects.