The method proceeds as follows: (1) Find a small set of points-called "critical points" -on the two surfaces with the property that if p is a critical point and p matches q, then q is also a critical point. The critical points are taken to be local extrema of either Gaussian or mean curvature. (2) Construct a rotation invariant representation around each critical point by intersecting the surface with spheres of standard radius centered around the critical point. For each of the resulting curves of intersection, compute a "distance map" function equal to the distance from a point on the curve to the center of gravity of the curve as a. function of arc length (normalized so that the domain of the function is the interval [0,1]). Cll the set of contours for a given critical point a "distance profile." (3) Match distance profiles by computing a "correlation" between corresponding distance contours. (4) Use maximal compatible subsets of the set of matching profiles to induce a transformation that maps corresponding critical points together, then use a cellular spatial partitioning technique to find all points on each surface that are within a tolerance of the other surface.

]]>* Create one or more human figures which are correctly scaled according to a specific population, or which meet certain size constraints.

* View the human figure in any of several graphical modes: stick figure, line or shaded polygons, or shaded BUBBLEPERSON.

* Position the figure in any admissible position within joint angle constraints, and with the assistance of a robotics reach positioning algorithm for limbs.

* Combine the figures with three-dimensional polyhedral objects derived from an existing CAD system.

* Create shaded graphics images of bodies in such environments.

* Use all TEMPUS features in an extensible and uniform user-friendly interactive system which does not require any explicit programming knowledge.

A brief summary of the software engineering of this system in a University environment is included. Other features of TEMPUS and differences between TEMPUS and other available body modeling systems are also discussed.

]]>A large number of different graphics hardware devices currently exist with a wide range of available functions. The CORE System provides device independence by shielding the applications programmer from specific hardware characteristics. The shielding is at the functional level: the device-independent (DI) system uses internal routines to convert the application programmer's functional commands to specific commands for the selected hardware device driver (DD). The progammer describes a graphical world to the CORE System in device-independent normalized device coordinates. The programmer also specifies the viewport on the logical view surface (output device) where a picture segment is to be placed.

As the CORE System becomes the accepted standard graphics package, program portability will become more feasible. Program portability means the ability to transport application programs between two sites without requiring structural modifications. The CORE System was designed for functional completeness so that any graphics function a programmer desires is either included within the system or can be easily built on top of CORE System routines.

]]>a) improve the spatial resolution

b) improve the visualisation of the data

c) improve the identification of anatomic structures

Thus, we shall not deal with different hardware, nor with various reconstruction algorithms. We shall assume that the data is given and ask what can be done from there on. Examples, documenting each of the above points, will be presented.

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