| 摘要 |
A color enhancement circuit according to the present invention extracts "sine-squared" (haversine) pulses representing absolute values for the derivatives of R-Y and B-Y color difference "sine-squared" transitions; multiples by offset, sign-inverted luminance, and adds the luminance-weighted "singe-squared" pulses to the composite video as color enhancement signals which exceed the NTSC-legal chroma bandwidth but are within the NTSC-legal luminance bandwidth. The pulses augment luminance during chroma transitions, restoring luminance contributions from chrominance which are lost when chroma subcarrier packet risetimes and bandwidth are limited by NTSC broadcast requirements.
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