PEDL87V21071-01
OKI Semiconductor
ML87V21071
2.1.2 Detected Noise Between Frames, Fields and Lines
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)
Table F2-1-2 Non-Linear Filter Noise Detection Area Settings
YSLT/CSLT
Noise detection line
Noise convergence line
Noise upper limit line
[3]
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
[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
[0]
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Inclination
1
Offset
Inclination
Offset
Inclination
Offset
7/8
3/4
1/2
1
7/8
3/4
1/2
1
7/8
3/4
1/2
1
7/8
3/4
1/2
–1
–3/4
–1/2
–3/2
YNS[5:0]
CNS[5:0]
YLM[4:0]
CLM[4:0]
0
0
Field-recursive
detection noise
output
Noise convergence line
Noise detection line
Input noise detection line inclination
1 or 7/8 or 3/4 or 1/2
31(MAX)
Non-noise detection area
Noise convergence line inclination
-1 or -3/4 or -1/2 or -3/2
Noise upper limit
line offset:
Noise upper limit line
YLM[4:0], CLM[4:0]
= 0 to 31
Noise detection area
(Differential absolute
value of difference
between fields
0
63(MAX)
|∆Y|, |∆C|) input
Noise convergence line offset: YNS[5:0], CNS[5:0] = 0 to 63
Figure F2-1-2 Field-Recursive Noise Motion Level Detection Noise Characteristics
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