ALLIED Vision Technologies Guppy F-503 - Manual (Page 109)

Description of the data path
GUPPY Technical Manual V7.1.0
109
This is for the first line pair:
The first chroma signal R-Y is created by subtracting the averaged pixels:
Formula 2 is used for the first chroma (color difference) signal V.
For the second line pair, the Y signal is formed from these signals as follows:
This is balanced since it is formed in the same way as for the first line pair.
In a like manner, the second chroma (color difference) signal U is approxi-
mated as follows:
In other words, the two chroma signals can be alternatingly retrieved from
the sequence of lines from R – Y and – (B – Y).
This is also true for the second field, which is generated by a vertical shift
by one line. Complementary filtering is thus a way to achieve higher sensi-
tivity at a slight expense of color resolution.
Formula 4: Y signal expressed via RGB and CyMgYeG
Formula 5: First chroma signal V
Formula 6: Y signal for second line pair
Formula 7: Second chroma signal U
Y
1
2
---
2 B

3 G

2 R
 + +   
1
2
---
G Cy +  
Mg Ye +   +    = =
R G +  
Ye =
R B +  
Mg =
G B +  
Cy =
with the assumption:
R Y – 2 R

G –  
Mg Ye +  
G Cy +   –   = =
Y
1
2
---
G Ye +  
Mg Cy +   +   
1
2
---
2 B

3 G

2 R
 + +    = =
B Y –   – 2 B

G –   – G Ye +  
Mg Cy +   –   = =