| 摘要 |
A method and apparatus are provided for preventing the existence of pseudo-sync pulses and added AGC pulses in an original video tape with copy protection from producing a poor t.v. picture when simply played on a VCR and viewed on a t.v. monitor. In a first embodiment, the horizontal sync pulses are amplified to eliminate jitter in the signal due to confusion with the chrominance or color burst signal. Further, the color burst signal may be subject to variable gain to correct the color tint. Finally, if desired all portions of an input video signal may be amplified, except for portions of the signal where pseudo-sync pulses and added AGC pulses are normally found, in order to brighten the signal. In another embodiment, all portions of the signal are amplified and the portions of the signal corresponding to pseudo-sync pulses and AGC pulses are attenuated to their normal 1 volt peak-to-peak level. The result of the present invention is such as to reestablish the normal horizontal sync pulse to its normal level, to put the color burst in its proper, ratio and to increase the video dynamic range.
|
