Cobalt Digital Inc 9932-EMDE, Руководство по эксплуатации продукта, Страница: 79 / 104

9932EMDE-OM (V1.4) 9932-EMDE PRODUCT MANUAL
3-41
Operating Instructions
9932-EMDE Function Menu List and Descriptions
Table 3-2 9932-EMDE Function Menu List — continued
Alpha Threshold keying allows cost-effective luminance keying
from low-cost generic file-based graphic sources. With the graphic
source applied to both the card Key and Fill inputs, the card Key
Alpha and Key Threshold controls can be set to easily optimize the
key/fill as shown below.
Key Threshold setting, when reduced, more readily
allows the key/fill input to assert itself over more
variations of program video luma levels. In the
example to the right, progressively reducing the
threshold setting allows more of the key/fill to assert
iteslf over the program video.
Key Alpha setting, when increased, increases the
opacity of the key/fill. In the example to the right,
progressively increasing the alpha setting increases
the key/fill opacity.
When both settings are optimized, the key/fill
appears consistent in opacity and free from edge
distortions or graphic bleed lines appearing in the
image.
Alpha Threshold
mode setting is
suited for graphic
sources using
black
backgrounds.
Reverse Alpha
Threshold mode setting is suited for graphic sources using
white backgrounds.
When using either alpha
threshold modes, set the Key
Source and Fill Source to use
the same source (in this
example, SDI input D).