Grass Valley DD35 Family v.3.1.5 - Manual (Page 197)

3. Menu Operation DD35 Production Switcher
3 – 45 Operating Instructions – Rev. 16 / 10.2001
Cleanup / Density or Clip / Gain mode:
Each keyer provides the possibility of processing the key signal with Cleanup /
Density or Clip / Gain mode. Either method can be used for acceptable keying re-
sult. The better choise is determined by the selected key source and associated
key signal. The choise should be made before making any key adjustments, subse-
quent switching between the two types will affect the keying result.
Both methods enhance the characteristic curve of the key signal. The only differ-
ence is the invariant center of rotation of the characteristic curve.
The automatic button 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.