| 摘要 |
The invention allows detecting which graphics, if any,have been added to the video signal at any given time by utilizing only the various signals provided by prior art hardware. A first video signal, graphics signal(s), and a second video signal are received. It is then determined which graphics, if any, are present in a given frame of the received second video signal based on comparing actual values of pixels of the received second video signal and calculated values of pixels derived from the first video signal, and the graphics signal(s),and the combination of graphics signal(s)which produces the best match is searched for. |
