![background image](http://html1.mh-extra.com/html/barco/hdf-w-series/hdf-w-series_installation-manual_474143094.webp)
9. Image
An example of alteration may be a DC component added to the signal, in the form of a DC offset repositioning the black level, since
this
black level
(
“brightness”
) will become crucial later on (clamping circuit) it will result in “black not being black”.
Another value that is subject to alteration is the amplitude of the signal, resulting in an altered “Gain” of the signal (
“white level”
or
contrast
).
The alterations of the three color signals will happen independently i.e. the colors will end to be unbalanced, image 9-29
B
Black level
0.7V
Image 9-28
Black level
Δ
G
ΔΒ
Δ
R
R
G
B
Image 9-29
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 9-30
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 !
90
R5905158 HDF W SERIES 10/07/2012
Содержание HDF W series
Страница 1: ...HDF W series Installation manual R5905158 01 10 07 2012 ...
Страница 4: ......
Страница 14: ...1 Safety 10 R5905158 HDF W SERIES 10 07 2012 ...
Страница 35: ...3 Physical installation Image 3 30 1 2 3 F Image 3 31 Center focusing R5905158 HDF W SERIES 10 07 2012 31 ...
Страница 42: ...3 Physical installation 38 R5905158 HDF W SERIES 10 07 2012 ...
Страница 60: ...5 Getting started 56 R5905158 HDF W SERIES 10 07 2012 ...
Страница 66: ...6 Quick set up adjustment 62 R5905158 HDF W SERIES 10 07 2012 ...
Страница 86: ...8 Input 82 R5905158 HDF W SERIES 10 07 2012 ...
Страница 126: ...10 Layout 122 R5905158 HDF W SERIES 10 07 2012 ...
Страница 136: ...11 Lamp 132 R5905158 HDF W SERIES 10 07 2012 ...
Страница 166: ...12 Alignment 162 R5905158 HDF W SERIES 10 07 2012 ...
Страница 224: ...14 Service 220 R5905158 HDF W SERIES 10 07 2012 ...
Страница 226: ...15 Maintenance 222 R5905158 HDF W SERIES 10 07 2012 ...
Страница 243: ...17 Servicing 1 Image 17 14 Z axis alignment R5905158 HDF W SERIES 10 07 2012 239 ...
Страница 244: ...17 Servicing 240 R5905158 HDF W SERIES 10 07 2012 ...
Страница 254: ...C Standard source files 250 R5905158 HDF W SERIES 10 07 2012 ...
Страница 258: ...D DMX chart 254 R5905158 HDF W SERIES 10 07 2012 ...
Страница 264: ...E Stacking HDF W series projectors 260 R5905158 HDF W SERIES 10 07 2012 ...