ml87v21071 Oki Semiconductor, ml87v21071 Datasheet - Page 35

• Manufacturer Part Number: ml87v21071
• Description: Video Signal Noise Reduction Ic With A Built-in Frame Memory
• Manufacturer: Oki Semiconductor

OKI Semiconductor
• 4 Continuous Code Detection
If 4 continuous codes are detected to be the same and their low frequency differential data absolute values are
equal to or greater than the continuous code motion detection level 1/2(YMS[3:1]), the data is judged to have
much motion, and the 4 continuous code motion flag (YMT4) = 1 is set.
If the absolute value is less than the continuous motion detection level, the data is judged to have little motion, and
the 4 continuous code motion flag (YMT4) = 0 is set.
By setting YMDM( SUB:50h-bit[4]) = 1, the detection precision of the 4-continuous code motion flag can be
improved.
• 5 Continuous Code Detection
If 5 continuous codes are detected to be the same and their low frequency differential data absolute values are
equal to or greater than the continuous code motion detection level 1/4 (YMS[3:2]), the data is judged to have
much motion, and the 5 continuous code motion flag (YMT5) = 1 is set.
If the absolute value is less than the continuous motion detection level, the data is judged to have little motion, and
the 5 continuous code motion flag (YMT5)=0 is raised.
By setting YMDM( SUB:50h-bit[4]) = 1, the detection precision of the 5-continuous code motion flag can be
improved.
From the differential data between fields, including chrominance signal motion and noise, the high frequency
component (∆HC) is filtered with the LPF, extracting only the low frequency differential data (∆LC).
Chrominance LPF: F(z) = (1/4)z
The low frequency differential data is assumed to have a large proportion of the motion component, so the
absolute value of that data (|∆LC|) is compared with the chrominance noise convergence level set in CNS[5:0] to
determine the amount of motion.
If the result shows that the differential absolute value is greater than the noise convergence level, the data is
judged to have a lot of motion, and the chrominance motion flag (CMT) = 1 is set.
If the differential absolute value is less than the noise convergence level, it is determined that there is not much
motion in the data, and the motion flag (CMT) = 0 is set.
This motion flag is used in adjacent pixel motion compensation.
Chrominance Level Motion Detection
Table F2-1-3 (3) Luminance 4 Continuous Code Motion Detection
Table F2-1-3 (4) Luminance 5 Continuous Code Motion Detection
Table F2-1-3 (5) Chrominance Level Motion Detection
Motion detection condition
Motion detection condition
Motion detection condition
-2
| ∆ LY| ≥ YMS[3:1]
| ∆ LY| < YMS[3:1]
| ∆ LY| ≥ YMS[3:2]
| ∆ LY| < YMS[3:2]
| ∆ LC| > CNS[5:0]
| ∆ LC| ≤ CNS[5:0]
+ (1/2)z
| ∆ LC| > 64
| ∆ LY| > 8
| ∆ LY| > 4
0
+ (1/4)z
2
Motion flag (YMT4)
Motion flag (YMT5)
Motion flag (CMT)
1
1
0
1
1
0
1
1
0
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