METHOD AND APPARATUS OF PERSPECTIVE TRANSFORMATION IN SCANNED RASTER VISUAL DISPLAY

摘要

1377821 Simulator display system SINGER CO 11 April 1972 [15 April 1971 23 Dec 1971] 16581/72 Heading H4F In an aircraft simulator or other type of trainer a simulated scene of the earth's surface as viewed from the observer's viewpoint is produced by raster scanning a spot across a simulated display window, the scanned spot being modulated by a video signal produced by scanning an image source depicting the relevant portion of the earth's surface as viewed from an image viewpoint which is different from the observer's viewpoint, this difference in viewpoints being compensated for by modifying the raster scanning of the image source, i.e. the shape of the image source analyzing raster is modified to give a desired perspective change. Specifically the line of sight from the observer passing through the instantaneous spot position on the display window is used to determine the point of intersection with the earth's surface, and the point on the image source (such as a film) corresponding to this earth intersection point is computed and the analyzing spot appropriately positioned on the image source. The image source may comprise a frame of film, the image picked up by a probe in a camera model system, a displayed digitally generated image, or an orthophoto transparency, which is analyzed by a television camera or flying spot scanner. The display may be produced by one or more C.R.T.'s, television projectors or laser projectors. A detailed description of the analyzing raster computation is given in the Specification.