Barco R9010570 - Manual (Page 63)

7. Advanced
B
Black level
0.7V
Image 7-36
Black level
∆ G ∆Β
∆ R
R
G
B
Image 7-37
The objective of input balancing
The objective in input balancing is to “set” the same black level and the same white level for the three colors of a particular input
source.
Black level setting : brightness
White level setting : contrast
The same absolute black and white level for the three colors allows the same reference for Brightness and contrast control of the
picture !
These two references also set the range in which the ADC will work for that particular source ( this explains also why each input
balance setting is linked to a particular source and thus saved in the image file).
How can it be done ?
To balance the three color signals of a particular source there are conditions; in fact we must know the black and the white level of
the source i.e. :
1.
the source in question must be able to generate a white signal, ideally a 100% white (background) full screen pattern
2. the source in question must be able to generate a black signal, ideally a 100 % black (background) full screen pattern
A B
Image 7-38
White balance : In the projector, we will set the contrast for each color until we get a 100% light output picture when projecting a
100% white image (image A)
Black balance : In the projector, we will set the brightness for each color until we get a 0% light output picture when projecting a
100% black image (image B).
The changeover from min to max is indicated by the apparition of bright spots also called “digital noise”
R59770079 BARCO ID H250/500 23/07/2007 59