MN673794 Datasheet, PDF (19/42 Pages) Panasonic Semiconductor – LSI FOR MPEG

MN673794
6. Noise Reduction (NR)
Figure 3.6-1 shows the block diagram of noise reduction.
The input signal will be output with the NR-ROM output signal subtracted.
Furthermore, the output signal will be delayed in fields or frames, and the difference from the input signal will be
input into the NR-ROM. This is called recursive noise reduction with a variable recursive coefficient.
Figure 3.6-2 shows the characteristics of the NR-ROM.
The field/frame differential signal contains a movement or noise signal.
When the field/frame differential signal is high, the signal is considered a movement signal. When the signal is
low, it is considered a noise signal. The strength or gain of the filed/frame differential signal for noise reduction
can be changed by register settings.
Figure 3.6-3 shows the characteristics of noise reduction.
For details, refer to the table of registers.
Input
ROM
Frame/Field
memory
Fig. 3.6-1 NR Block Diagram
Output
ROM
output
yupslp
cupslp
yupslp
cupslp
NR
gain
yupslp
cupslp
yupslp
cupslp
Frame/Field
Differential value
Fig. 3.6-2 NR-ROM characteristics
yupslp
cupslp
yupslp
cupslp
Frame/Field
Differential value
Fig. 3.6-3 NR characteristics
SDF00032BEM
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