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SynthEyes will read the alpha channel from many common image file formats. The alpha channel can be used for foreground/background object separation during
auto-tracking, planar tracking, or simply passed through during stabilization or undistortion for use in downstream effects.
SynthEyes can also read alpha-channel data from separate alpha files , either if you select them specifically (explicitly), or automatically (implicitly) if they are named appropriately (as controlled by a preference in the Image Input section).
Separate alpha channel data is always an image sequence (never a movie), though it can be added to image sequences or movies. For sequences, the file number in the alpha image must always match the file number in the image itself, to avoid massive confusion.
Tip : If the alpha sequence ends early (or has missing frames), the last alpha frame in a shot will be repeated, making it easy to a single alpha frame for an entire shot.
If the file already contains an alpha channel, there is no search for an implicit separate alpha: the existing alpha channel is preserved. If an explicit separate alpha sequence is specified (you selected it), then that alpha data is used and replaces the existing alpha channel.
The "Keep Alpha" checkbox on the shot settings panel controls whether the alpha data is read and stored, so that you can ignore it (and save memory) if you want. If an implicit alpha sequence is present, you must turn on Keep Alpha manually. If you explicitly select an alpha sequence, Keep Alpha is turned on automatically, though you can turn it off if you like.
©2024 Boris FX, Inc. — UNOFFICIAL — Converted from original PDF.