Abstract: A method for providing rapid generation of photo-realistic imagery for use in a display system. The display system includes a memory which contains first and second ortho-rectified data layers. The first data layer includes a digitized photograph of known resolution together with spacing values and the second layer includes digitized elevation data corresponding to the photograph in the first data layer. The method includes the steps of scanning corresponding portions of the first and second data layers out of memory, removing hidden surfaces from the scanned portions, dividing the scanned portions into a plurality of two pixel by two pixel cells so as to form the cells using adjacent pixels from the data layer, further dividing the cells into triangular sections having vertices, projecting the vertices into the viewscreen using the coordinates in the second layer and the known spacing values, and shading the area subtended by the projected vertices.

Abstract: Information on the shape of an object is extracted by generating an image of the object, encoding and ordering the boundary points of the image, selecting points on the outermost portions of the boundary, partitioning the boundary at the selected points into segments of either a first or second kind wherein the segments are distinguished according to a selected smoothness test, and segments of the first kind are smoother than segments of the second kind, partitioning each segment of the second kind into segments of the first or second kind according to the above test, and continuing the partitioning of each of the segments of the second kind into segments of the first or second kind until no further segments of the second kind are identified. An apparatus for performing the above steps is also disclosed.