COLOURIZER & COMPOSITOR
The
Colourizer & Compositor
section is a voltage controlled analogue video mixer. It features two RGB
input channels, individual RGB controls and several advanced colour processing effects. We designed
this section to be capable of addressing all the essential colour mixing required for a small to medium
sized modular video synthesis system. The output of this section is sent directly to the
Output Encoder
.
Frontpanel
A. Channel A RGB input jacks.
RGB inputs to Channel A.
B. Channel B RGB input jacks.
RGB inputs to Channel B.
C. Composite input jack.
Voltage control over the selected
Composite mode
(D)
.
D. Composite mode switch.
Selects formula used to
combine Channel A
(A)
and Channel B
(B)
:
E. RGB colour controls.
Clockwise rotation adds the
selected colour, while counterclockwise subtracts.
F. Colourize input jack.
Voltage source of the RGB colour controls
(E).
Connected to 1V by default.
G. Mix A on/off switch.
Adds the output of the RGB colour controls
(E)
to Channel A
(A)
.
H. Mix B on/off switch.
Adds the output of the RGB colour controls
(E)
to Channel B
(B)
.
I. Spectrum on/off switch.
Translates the value of the Colourize input
(F)
to colour channels:
J. Solarize on/off switch.
Inverts all color values below 0V.
K. Negative on/off switch.
Subtracts all color values from 1V.
Block Diagram
Multiply
(A*B)+((1-B)*VC)
Fade (center)
(A*(1-VC))+(B*VC)
Sum
A+((-B*(1-VC))+(B*VC))
VC = Composite input signal
(C).
0V – 0.5V
Red
0%
Green
0% to 100%
Blue
100% to 0%
0.5V – 1V
Red
0% to 100%
Green
100% to 0%
Blue
0%
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