ml87v21071 Oki Semiconductor, ml87v21071 Datasheet - Page 33

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

2.1.2 Detected Noise Between Frames, Fields and Lines
OKI Semiconductor
The differences are calculated between
- one pixel in the current field and one pixel preceding by one frame,
- one pixel in the current field and two pixels by one field, and
- one pixel in the current field and one pixel preceding by one line.
Among the absolute values of these differences, the smallest value is selected.
From the differential values between frames and between fields (∆Y, ∆C), the signal with a low level of absolute
value for the differential values (|∆Y|, |∆C|) is judged to be the noise component and the signal with a high level is
judged to be the motion component. The data judged to be the noise is extracted as the motion level detection
noise.
The detected noise is output after being filtered by the area covered by the input noise detection line, the noise
convergence line, and the noise upper limit line. The inclination of the input noise detection line is set by
YSLT[1:0](SUB:4Ah-bit[5:4]) and CSLT[1:0](SUB:4Bh-bit[5:4]), the inclination and offset of the noise
convergence line are set by YSLT[3:2](SUB:4Ah-bit[7:6]), YNS[5:0] (SUB:4Ch-bit[5:0]), CSLT[3:2]
(SUB:4Bh-bit[7:6]) and CNS[5:0] (SUB:4Dh-bit[5:0]), and the offset of the noise upper limit line, which has 0
inclination, is set by YLM[4:0] (SUB:4Eh-bit[4:0]) and CLM[4:0] (SUB:4Fh-bit[4:0]). (Figure F2-1-1)
31(MAX)
detection noise
Field-recursive
[3]
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
Figure F2-1-2 Field-Recursive Noise Motion Level Detection Noise Characteristics
output
YSLT/CSLT
0
[1]
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
[2]
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
Table F2-1-2 Non-Linear Filter Noise Detection Area Settings
Noise convergence line
[0]
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Inclination
Noise convergence line offset: YNS[5:0], CNS[5:0] = 0 to 63
Noise detection line
7/8
3/4
1/2
7/8
3/4
1/2
7/8
3/4
1/2
7/8
3/4
1/2
1
1
1
1
Input noise detection line inclination
Noise detection area
Offset
0
1 or 7/8 or 3/4 or 1/2
Inclination
Noise convergence line inclination
Noise convergence line
–3/4
–1/2
–3/2
–1
-1 or -3/4 or -1/2 or -3/2
Non-noise detection area
CNS[5:0]
YNS[5:0]
Offset
Noise detection line
Noise upper limit line
Inclination
63(MAX)
Noise upper limit line
0
YLM[4:0], CLM[4:0]
(Differential absolute
Noise upper limit
value of difference
PEDL87V21071-01
|∆Y|, |∆C|) input
between fields
line offset:
= 0 to 31
CLM[4:0]
YLM[4:0]
ML87V21071
Offset
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