Method and system for compression and reconstruction of cultural data for use in a digital moving map display

摘要

A method and digital system for the compression and reconstruction of cultural data for use with display systems, such as a system for producing a real time moving map display of terrain, provides a modified footprint/common boundary technique for data compression in which the footprint extends forward of the last point generated along a line in the direction of the line to that point. The particular scheme for compressed data reconstruction employs the storage of footprint data in such a manner that change in line direction information is automatically provided along with the necessary delta data information so that the direction of the line can be constantly updated as each point is generated. The compression of area cultural features involves a double compression of data based on a common boundary approach and the inner compression techniques of the modified footprint technique. In addition, in the reconstruction of compressed cultural data, changes in scale factor are accommodated along with feature deselection based on the selected scale factor.