Turn on Alpha for any layer and its matte becomes a deliverable channel — no separate mask-building pass, no extra tool required. Every layer with Alpha enabled folds Add or Subtract into one combined per-frame channel, refined with the same matte tools as the Mask tab, and delivered embedded in your file or as its own independent sequence.
Turn alpha on for any layer — a colour qualifier, a geometric shape, a Segment layer — and it contributes to one combined alpha for the clip, folded Add (union) or Subtract (punch a hole) in whatever order the layers already sit in. There's nothing extra to build: the same selection that's grading the shot is the selection that becomes its matte.
Before delivery, the combined alpha runs through the same refinement engine as the Mask tab's finesse strip — despeckle, hole fill, expand/contract, feather, intensity, invert, plus gamma and a lo/hi threshold specific to the Alpha tab — so a matte that needs cleaning up doesn't need a trip to another application first.
Delivery is two independent questions, not one mode picker. Does this format's own file carry alpha in it — gated per format, since not every codec can. And separately, should a standalone matte sequence also be written, in its own EXR, DPX, or PNG choice, regardless of what the main deliverable format is. Turn on either, both, or neither.
Same engine, same controls, wherever a matte needs cleaning up in Transduce.
| Control | What it does |
|---|---|
| Despeckle / Hole Fill | Connected-component area thresholds — clear small false-positive islands or fill small holes without a manual paint pass. |
| Expand / Contract | Grow or shrink the matte edge in pixels. |
| Feather | Edge-aware guided-filter softness, not a blind Gaussian blur — see Guided-Filter Feathering. |
| Intensity | Overall matte strength — dial the whole alpha up or down. |
| Gamma / Lo / Hi | Alpha-specific tone shaping and threshold clamp, for mattes that need a harder or softer roll-off. |
| Invert | Flip subject and background without rebuilding the selection. |
| Question | Behaviour |
|---|---|
| Embed in the main file? | Per-format — on for encoders that carry alpha (EXR, PNG, ProRes, DPX RGBA) when their own "Include Alpha Channel" option is on. |
| Write a standalone matte? | One global toggle, independent of the main format — its own dedicated EXR/DPX/PNG matte encoder, so a matte sequence can exist even when the main deliverable can't carry alpha at all. |
The selection that graded the shot is the selection you hand off — embedded, standalone, or both.