Secam color difference signal processing method
AssigneeOki Electric Industry Co., Ltd.
InventorYasuhiko Okamoto
Life of this patent
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Abstract
A SECAM video signal is decoded by selecting different combinations of chrominance signals according to the luminance difference between the current line and the preceding line. The chrominance signals from the current line and the preceding line are selected when this difference is smaller than a threshold. The chrominance signals from the current line and the next line are selected when the difference is greater than the threshold. The average value of the chrominance signals in the preceding and following lines may be calculated and selected in place of the chrominance signal from the preceding line.
Claims20
A method of processing a SECAM color difference signal, comprising:
- processing a SECAM video signal to obtain a first luminance signal and a first chrominance signal;
- delaying the first luminance signal by one horizontal interval to obtain a second luminance signal;
- delaying the first chrominance signal by one horizontal interval to obtain a second chrominance signal;
- delaying the second chrominance signal by one horizontal interval to obtain a third chrominance signal;
- calculating a difference between the first luminance signal and the second luminance signal;
- and
- selecting different combinations of the first, second, and third chrominance signals according to the difference.
A decoder for decoding a SECAM video signal including a luminance signal and a chrominance signal, the decoder comprising:
- a first delay circuit for delaying the chrominance signal by one horizontal interval to obtain a first delayed chrominance signal;
- a second delay circuit for delaying the first delayed chrominance signal by one horizontal interval to obtain a second delayed chrominance signal;
- a third delay circuit for delaying the luminance signal by one horizontal interval to obtain a delayed luminance signal;
- a luminance difference comparator for taking a difference between the luminance signal and the delayed luminance signal and generating a control signal from the difference;
- and
- a selector for selecting different combinations of the chrominance signal, the first delayed chrominance signal, and the second delayed chrominance signal according to the control signal.
Dependencies are inferred from the claim text.