| 摘要 |
<p>Apparatus for generating halos about CRT display symbols, to distinguish them from background video, reads, from an image memory (43), video Bit signals corresponding to a CRT picture element PI.J, and the immediately surrounding CRT picture elements. A digital signal is generated therefrom representing a first Boolean function (44). The intensity of the background illumination at PI.J is unaltered, in response to a digital signal of zero, and is diminished by one-half, in response to a digital signal of ONE. A preferred embodiment reads additional signals and employs a second Boolean function. </p> |
