| 摘要 |
In the system disclosed, scanning is carried out on the image source side with a frame corresponding to an enlarged 16:9 picture ratio. On the emitter side, every fourth line of the picture signal is first isolated and the remaining lines are compressed. A 4:3 standard receiver reproduces a corresponding image in the "letter box" format. The 16:9 receiver should reconstruct the original picture signal. First solution: the isolated lines are expanded for the duration of a complete picture, modulated to a second picture carrier at the upper end of the transmission channel outside the standard intermediate frequency resonance curve, and then demodulated, expanded and reintroduced into the 16:9 receiver. Second solution: analog-coded line difference signals in the level between the black and synchronization pulses are transmitted in the freed spaces at the upper and lower edges of the picture, decoded in the 16:9 receiver and reused. Third solution: additional digital data, e.g. motion vectors, are transmitted in the spaces freed at the upper and lower edges of the picture, and used by the 16:9 receiver to interpolate the missing lines. Application to television receiving sets with 4:3 and 16:9 picture ratio. |
