ml87v21071 Oki Semiconductor, ml87v21071 Datasheet - Page 31

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

OKI Semiconductor
• Principles of Adaptive Noise Reduction
Adaptive noise reduction is achieved through the selection of noise reduction data, which utilizes the
correlative relationships between frames, fields, and lines for the pixels for which noise reduction is to be
performed, as shown in Figure F2-3 (3).
The distinguishing characteristics of each correlation are as shown below.
Between frames
Between fields
Between lines
This IC detects motions and edges between lines, frames, and fields, based on the features described above, to
select data after better correlated NR and achieve effective noise reduction.
→Effective for moving images, but not effective for edges (medium NR, no
Figure F2-1 (3) Noise Reduction Correlation
: Same position (most effective), time difference 2V (less effective)
→Effective for still images (good NR, substantial afterimage)
: Position 0.5H different (effective), time difference 1V(effective)
→More effective for moving images than frames, more effective for still images than
: Position 1H different (less effective), time difference 0 (most effective)
lines (medium NR, medium afterimage)
afterimage, no NR for edges)
Direction of V
Time axis
: NR-target pixel
: NR
1V
2V
1V
1H
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