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10. Image
Black level
Δ
G
ΔΒ
Δ
R
R
G
B
Image 10-30
One can conclude here that a good color tracking can only be met by using three previously (input) balanced
color signals
Analog Digital Conversion
The analog color signals must pass through an Analog/Digital conversion circuit prior to any digital processing in the PMP.
A typical ADC transforms the analog value into an 8 bit coded digital signal.
The graphic shows that when converting a signal containing a DC offset component the range of the converter is not optimally used.
Black level
Δ
R
ADC
0
255
i1 : superfluous information
i2 : video information
Image 10-31
One can conclude here that a good data conversion can only be met by using three previously (input) balanced
color signals
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
fi
le).
10.3.7.2 Adjusting the input balance
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
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R5905303 HDQ 2K40 02/03/2015
Summary of Contents for HDQ--2K40
Page 1: ...HDQ 2K40 User and Installation manual R5905303 09 02 03 2015 ...
Page 4: ......
Page 10: ...Table of contents 6 R5905303 HDQ 2K40 02 03 2015 ...
Page 18: ...1 Safety 14 R5905303 HDQ 2K40 02 03 2015 ...
Page 54: ...4 Input Communication 50 R5905303 HDQ 2K40 02 03 2015 ...
Page 78: ...6 Getting started 74 R5905303 HDQ 2K40 02 03 2015 ...
Page 118: ...9 Input 114 R5905303 HDQ 2K40 02 03 2015 ...
Page 148: ...10 Image 144 R5905303 HDQ 2K40 02 03 2015 ...
Page 166: ...11 Layout 162 R5905303 HDQ 2K40 02 03 2015 ...
Page 176: ...12 Lamp 172 R5905303 HDQ 2K40 02 03 2015 ...
Page 302: ...15 Service 298 R5905303 HDQ 2K40 02 03 2015 ...
Page 318: ...17 Removal and installation of the projector covers 314 R5905303 HDQ 2K40 02 03 2015 ...
Page 322: ...A Specifications 318 R5905303 HDQ 2K40 02 03 2015 ...
Page 326: ...B Standard source files 322 R5905303 HDQ 2K40 02 03 2015 ...
Page 330: ...C DMX chart 326 R5905303 HDQ 2K40 02 03 2015 ...
Page 334: ...D Environmental information 330 R5905303 HDQ 2K40 02 03 2015 ...