Barco BarcoiQ GRAPHICS 500, Owner'S Manual

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7. Image Menu
Image 7-23
7.7 Blanking
Blanking in the Image menu
The blanking in general allows to blank unwanted video information (noise in the top or bottom of the image).
The blanking in the image menu is the same as in the Display settings menu except for the fact that here the blanking settings are
stored in the image files. In other words each custom file or source has its own blanking values.
See the blanking procedure in the Display settings menu.
If the selected source is not entirely displayed always check first the blanking settings in the image menu
since the active custom file may contains blanking.
7.8 Input balance
Introduction: Unbalanced color signals
When transporting signals, there is always a risk of deterioration of the information contained in the signals.
In case of information contained in the amplitude of the signals which is the case of data color signals (R, G, B),image 7-24 ,we are
quite sure that the amplitude of these color signals is subject to alterations.
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 7-25
B
Black level
0.7V
Image 7-24
R5976367 BARCOIQ GRAPHICS 500 01/02/2007 69