Grass Valley DD35 Family v.3.1.5 - Manual (Page 217)

3. Menu Operation DD35 Production Switcher
3 – 65 Operating Instructions – Rev. 16 / 10.2001
3.7.5.2 Function Buttons
For details refer to section Introduction.
The Key PVW button displays the keying result or the key signal on the preview
monitor to permit optimization.
This function permits adjusting a keyer which is not selected in the Transition panel.
If you press Key PVW repeatedly, the following signals can successively be
switched to the preview monitor:
D
original key fill signal on current background picture
D
key control signal as black-and-white signal.
Cleanup / Density or Clip / Gain mode:
Each keyer provides the possibility of processing the key signal with the Cleanup
/ Density or Clip / Gain mode. Either method can be used for acceptable keying
results. The better choise is determined by the selected key source and the associ-
ated key signal. The choise should be made before making any key adjustment,
subsequent switching between the two types will affect the keying results.
Both methods enhance the characteristic curve of the key signal. The only differ-
ence is the invariant center of rotation of the characteristic curve.
Each automatic run resets all four parameters.
The Cleanup / Density method influences only one end of the key area and keeps
the other one invariant.
Cleanup influences only the area of the background. Key levels are
increasingly limited to black, i.e. ”cleaned”. Noise and
slight shadows in this area will disappear.
Density influences only the area of the foreground. Key levels are
increasingly limited to white to the unity value ”1”, which
corresponds to the ”dense” foreground.
The Clip / Gain method influences both ends of the key area and leaves only one
selectable, average clip value invariant.
Clip determines that key signal level in the proximity of which linear,
unlimited keying has to be performed (effective only at Gain > 1).
Gain determines by gain change the width of the area around
Clip within which linear, unlimited keying has to be performed.
Delegate
PVW