1. In an image display system for displaying, on a viewable display screen, information defined by a plurality of graphics processing language (GPL) commands, a video graphics processor for receiving the GPL commands that define the information for display on the display screen and operable for interpreting the received GPL commands to generate from the received GPL commands video imaging data representing the information, said generated video imaging data comprising a multiplicity of video imaging data points transferable to the display screen for displaying the information on the display screen; and a comparator processor for receiving the GPL commands that define the information for display on the display screen and operable for interpreting the received GPL commands to generate from the received GPL commands selected points of light comprising a limited subset of said multiplicity of video imaging data points generated by said video graphics processor, said comparator processor being further operable for comparing each of said generated points of light to a respective corresponding video imaging data point of said video imaging data generated by said video graphics processor to thereby validate the video imaging data generated by and operation of said video graphics processor.