Method and apparatus for intensity shading in a visual display

摘要

An apparatus for generating computed images on an electronically controlled display surface is provided with an improved intensity shading generator. The shading generator operates by assigning each scan line of a raster display a fixed intensity between first and second points. The sweep position is monitored and each succeeding scan line between an initial position and a break point position of the image is monitored. The sweep intensity is incremented for each sweep line until the break point is reached, at which time new values for intensity are generated. The shading generator of this invention greatly reduces the bandwidth required to generate accurately placed intensity gradients perpendicular to the horizon in a displayed image system.