2011

4-point tracking Tracks four features, also referred to as corner pinning.
With four-point tracking, four trackers are used to generate tracking data for
anchoring the four corners of a bilinear surface to background footage.
alpha The name given to a fourth channel matte when bundled together
with a three-channel color image. Also known as a matte channel. An alpha
channel can be further described as either: 1. A TV signal that defines a portion
of an image or clip to be keyed, or overlaid with a second image. A grayscale
representation of an image used to create a mask for keying images.2. A matte
or mask that defines a portion of an image or clip. The portion of a
four-channel image that is used to store transparency information. 3. A raster
channel defined by a paint or brush stroke.
animation The process of creating the illusion of moving images by
displaying sequential images in rapid succession. In each successive image,
two or more values are changed over time, and the items drawn or recorded
in the images appear to move.
animation curve Also known as function curve or fcurve. It is a graphical
representation of an animated parameter. The time and value of the animated
parameter is displayed on two axes: the vertical axis representing the value,
and the horizontal axis representing the time.
AutoKey A mode that, when activated, sets a keyframe whenever you change
the selected object's properties.
background The composition background defines the rendering plane and
sets its format after which other layers can be created.
bit depth 1. The number of bits used to represent the color of a pixel. Black
and white images use a bit depth of 1; 16-color images use a bit depth of 4,
256-color images use 8, and so on. 2. The number of bits used to represent an
audio sample. The more bits there are, the more accurately you can represent
the amplitude at that point in time.
blue screen A special effects procedure in which the subject is photographed
in front of a uniformly illuminated blue or green background. A new
background image can be substituted for the blue or green during the shoot
or in post production through the use of chroma key. See also keying.
Boolean A system of logic that lets you combine objects using logical
operators, such as And, Or, Xor, Min, and Max. Boolean operators can be used
for combining mattes in a single layer.
browsers A generic term which refers to the program or tool used for
information searching in a window.
878 | Appendix E Glossary