| 摘要 |
<p>A raster scan display system is provided for composition of plural frame color images. First and second frame buffers, which store first and second frame color images respectively, are accessed in synchronization with a CRT. Then the first and the second frame streams of color pel data are generated from the first and the second frame buffers respectively. Subsequently the first stream of color pel data is compared with a predetermined color, and at the time when the comparison indicates that the colors are not the same, the first stream of color pel data is sent to the CRT. When the comparison indicates that the colors are the same, however, the second stream of color pel data is sent instead. Consequently, the first frame color image except of the part of the predetermined color is superimposed on the second frame color image. It is as if the part of the predetermined color in the first frame color image becomes transparent.</p> |
