Glossary
Interlaced
An Interlaced video format starts at the top of the
screen and draws all the odd number scan lines and
then all the even number scan lines in sequence. This
results in half the image being drawn in one pass and
the other half of the image being drawn in the second.
These two passes are called Fields, where the first pass
is called Field 1 and the second pass is called Field
2. When both Field 1 and Field 2 have been drawn,
resulting in a complete image, you have a single
Frame.
Progressive
A Progressive scan video format draws each scan
line in sequence, starting from the top of the screen
and working to the bottom. Unlike Interlaced, with
Progressive scan the entire image is drawn at one time,
in a single pass. This means that there are no fields in a
Progressive scan image.
Auto Key
A pairing of two video signals, a key video and a key
alpha, to create a key. In the switcher, you associate the
fill and alpha so that the switcher knows which alpha
to use when the video is selected.
Auto Transition
An automatic transition in which the manual
movement of the fader handle is simulated
electronically. The transition starts when the
AUTO
TRANS
button is pressed and takes place over a pre-
selected time period, measured in frames.
Chroma Key
Chroma Key is a key in which the hole is cut based on
a color value, or hue, rather than a luminance value or
alpha signal. The color is removed and replaced with
background video from another source.
Cut
An instantaneous switch from one video signal to
another.
Dissolve
A transition from one video signal to another in
which one signal is faded down, while the other is
simultaneously faded up. The terms mix or cross-fade
are often used interchangeably with dissolve.
Field
One half of a complete picture (or frame) interval
containing all of the odd, or all of the even, lines in
interlaced scanning. One scan of a TV screen is called
a field; two fields are required to make a complete
picture (which is a frame).
Force, Mask
An effect that forces the masked region to the
foreground but is not bound by the key. For example,
if you have a key and apply a mask to it. The masked
area is bound by the edges of the key. When force is
turned on, the masked area is filled with the video from
the key (nothing appears masked) but you can move
the mask outside of the key and the key video is still
filling the masked region.
Frame
One complete picture consisting of two fields of
interlaced scanning lines.
File Transfer Protocol
A network protocol that is used to transfer files from
one host computer to another over a TCP-based
network.
Gain
Gain represents the range of signal values present in
a video signal from a lowest to a highest point (from
black to white for example). Increasing gain expands
this range, while decreasing gain compresses this
range. Clipping occurs if applied gain changes cause
output signal values to fall outside the allowable range.
Generally, increasing the gain for a specific color
component causes the video signal colors to become
increasingly saturated with that color. Similarly,
decreasing the gain for a specific color component
progressively removes that color component from the
output video signal.
Gamma
Gamma corrections introduce non-linear corrections to
a video signal. A gamma correction can be described
as taking a point on the output versus input video
signal line and pulling it perpendicularly away from
the line. The result is a Bezier curve between the start,
the new point, and the end point. Generally, increasing
the gamma value adds more of the component to the
video signal in the location of the gamma offset point.
Decreasing the gamma value reduces the amount of
the component in the video signal in the location of
the gamma offset point. Moving the gamma offset
point allows you to select which part of the input video
Carbonite Black UltraChrome User Manual (v1.0) — Glossary •
43