Glossary
AE Plug-in: component of PatchMaker distribution designed according to AE plug-in interface specifications and destined for implementation of bidirectional communication between the applications.
Alpha channel: portion of the image containing information about pixel transparency rather than color. Alpha channel is important for overlays, see Alpha channel in overlay.
Footage: a sequences of frames stored on disk as a series of still images or as an AVI movie.
Key frame: a frame of the underlay which has a mask associated with it that determines objects to be tracked. The key frame is a property of the tracking segment, and is not subject to change.
Mask: a binary image that defines objects in the scene, the motion of which is to be tracked. The frame which the mask is associated with is called the key frame.
Match frame: the single frame of the underlay at which the overlay position is fixed by user rather than computed by the tracking algorithm.
In stabilizing, match frame is called the fixing frame, and represents the frame that remains untransformed, while all other frames are transformed in such way that the masked object holds the same position as it has at the fixing frame.
Overlay (Patch): an image (still overlay) or a video sequence (live overlay) containing objects that should be superimposed over the underlay according to the motion of objects in it. Overlay also stands for the set of (partially) opaque pixels in such image or video sequence.
PatchMaker Project: a file with '.pmp' extension which stores references to the footage, arrangement of tracking segments, current settings of the algorithm parameters, and all the computed data from a PatchMaker session.
Segment: the definition of a tracking procedure that is determined by a key frame, a mask associated with it, a set of parameters for the tracking algorithm, and tracking bounds in forward and backward direction.
Underlay: a video sequence containing objects, the motion of which is to be determined by motion tracking.
Work Area: continuous range of frames in composition referred to by some operations in PatchMaker, such as playback and rendering.
