Hughes Aircraft Company

Arthur F Griffin

Norton L Moise

Caesar P Ancheta

A process for extracting the precise perimeter of buildings from down-looking terrain images. The process works for any rectilinear building shape, and no restrictions are placed on the orientation or scale of the buildings within an image. The process has the advantages of robustness and execution speed. The process is robust in that it can extract building perimeters from a digitized image in the presence of multiple noise sources. The execution speed is proportional to N+M, where the size of the image is N by M pixels.

Rectilinear object image matcher

A method for use with a vehicle simulator which provides for the rapid update of displayed terrain data in areas of non-visible terrain surfaces and terrain image discontinuities. The method is for use with a system which projects a time-varying computer-generated image scene representative of the terrain as viewed from a moving vehicle. The image scene is derived from a digital data base stored in slow speed secondary memory. The method includes the steps of predicting, by means of line-of-sight sampling ray, which segments of the data base could be visible after a predetermined time interval. The data base is accessed for the predicted segments of data and these segments are retrieved therefrom. The data segments designated are then stored in predetermined memory locations in high-speed main memory. Finally, selected ones of the stored segments are displayed based on the actual vehicle path and position after the predetermined time interval has elapsed.

Predictive look ahead memory management for computer image generation in

The present invention's fundamental technique for transferring data between two operationally-juxtaposed memories basically entails thress steps: First, a sequential accessing of specified portions of the memories; second, a pair-wise comparison of the accessed data items; and third, a 'diagonal' exchange between the subject memories of certain ones of the data items. The technique thus begins with the sequential accessing, within each of the subject memories, of each of a plurality of memory portions. This sequential accessing thereby establishes within each memory a presently-accessed portion and a plurality of subsequently-accessed portions. The pair-wise comparison of the data items from the respective presently-accessed portions is performed next. Upon the occurrence of a match condition between the paired items, the presently-accessed item from a given one of the memories is then 'diagonally' exchanged with the item from a subsequently-accessed portion in the other memory. In a more-specific embodiment of the invention, a self-associating information-retrieval capability may be realized by utilizing the fundamental data-transfer technique as the basic mechanism for exchanging information between adjacent levels of a branched-hierarchy memory array.

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Redondo Beach, CA, United States of America

Arthur F Griffin