| 摘要 |
An enhancement system is disclosed for enhancing the signal scrambling effects generated by, for example, a sync suppression scrambling system, while at the same time providing for compatibility with sync suppression scrambled signal decoding circuits of existing television sets. To this end, first and last portions of selected television lines in a field of video are modified by the selective application at various times of a signal of about blanking level to provide horizontal enhancement via fake horizontal sync pulses. In a modified technique, a selected number of the first and last television lines in the video field are modified by the selective application of a signal from about blanking level to about gray level to also provide vertical enhancement via resulting fake vertical sync pulses during the scrambling process. |
