HD49801FB Datasheet, PDF (16/43 Pages) List of Unclassifed Manufacturers – Digital Signal Processing IC for CCD Cameras

HD49801FB
State Data A6: Color difference gain, base clip
This data determines the signal levels of the color difference signals.
HD49801FB
C clip CL_C
R-Y gain G_R-Y
R-Y gain G_R-Y
Address
D3 D2 D1 D7 D6 D5 D4 D3 D2 D1 D7 D6 D5 D4 D3 D2 D1 0 1 0 1
• Color difference gain control characteristics
8
R-Y
– ¹²⁸ to + ¹²⁷
256
256
–CL _C
+CL _C
Base clip
G_R-Y
×
Out
8
In
(R-Y)'
8
B-Y
– ¹²⁸ to + ¹²⁷
256
256
–CL _C
+CL _C
0 to ⁷
256
CL_C
G_B-Y
×
8
(B-Y)'
G_R-Y, G_B-Y = D7 × 2⁰ + D6 × 2^–1 + D5 × 2^–2 + D4 × 2^–3 + D3 × 2^–4 + D2 × 2^–5 + D1 × 2^–6
(0 to 2)
• Base clip level control characteristics
C_LC max = 7/256 = 0.0273437
C_LC = D3 × 2^–6 + D2 × 2^–7 + D1 × 2^–8
• Setting the gains
(a) The ratio of the gains R-Y and B-Y is determined by the color reproduction.
(b) Increase the color difference gain from the gain ratio from item (a) above.
(c) Set the gain to have a 10% to 20% margin from the gain at the point the output signal clips in item
(b) above.
I.e., (set gain) = (clipping gain) × 0.8 to 0.9
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