Video encoding using adaptive filters and variable threshold
US5097322A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 20, 1990 |
| Grant date | Mar 17, 1992 |
| Priority date | — |
| Expiry date | Aug 20, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/646
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An improved apparatus is provided for minimizing cross-color artifacts in the encoding and decoding of quadrature modulated color television signals during the encoding process, so that when the encoded video signals are decoded,s uch artifacts are minimized while a maximum amount of picture detail is preserved. A luminance signal is applied to both a delay element and an adaptive filter. The output of the delay element, a delayed luminance signal, is applied to a subtractor circuit. The output of the adaptive filter, an adaptive compensation signal, is applied to a variable limiter. Within the variable limiter, the adaptive compensation signal is applied to a rectifier/intergrator and a limiter circuit. The output of the rectifier/integrator, a cross-color activity signal, is sent to a scaler/combiner circuit top which is also optionally applied a chrominance activity signal. The scaler/combiner circuit weights these inputs with different factors before summing them. The output of the scaler/combiner circuit is a limiter control signal that is used to control how much of the adaptive compensation signal is applied to the subtractor circuit where it is substracted from the delayed …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.