| 摘要 |
A full dynamic-range video enhancer employs a detail process for lower level transitions in a video signal stream and a spectrum expander for higher level transitions. The characteristics of the detail processor enhancement signal are such that when combined with the main signal path, the rise times of lower level transitions are shortened, but with substantially no accompanying increase in the overall spectral bandwidth. The characteristics of the spectrum expander enhancement signal are such that when combined with the main signal path, the rise times of higher level transitions are shortened, but with an accompanying increase in the overall spectral bandwidth while maintaining low preshoot and overshoot characteristics. For a rising transition level the video enhancer provides enhancement initially by the detail processor, then a combination of the detail processor and the spectrum expander, and then by the spectrum expander. The video enhancer may advantageously be used in a television receiver following a line doubler.
|
