Difference Matte

Difference Matte operator properties for Script Engine. Builds a transparency matte by comparing the current frame against a reference still (a clean plate of the empty background) and treating any pixels that differ as foreground. Useful for locked-off camera shots that do not use a green/blue screen, security camera extraction, museum or product shots against a fixed wall, and any situation where the camera is static and only the subject moves. Sensitive to camera shake and lighting changes — pair with a stable mount and consistent lighting for best results.

Property	Type	Access	Description
`ShowAdvancedOptions`	`bool`	`get/set`	Reveals additional fine-tuning controls (colour tolerance, refinement, debug). Leave off for simple use; turn on when you need to tune individual channels or matte morphology.
`CleanPlatePath`	`Uri`	`get/set`	Path to the still image of the empty background (no subject). Capture the clean plate with the exact same camera, lens, exposure, and lighting as the live shot.
`ReloadCleanPlateCmd`	`Command`	`get`	Reload the clean plate image from disk — use after replacing the file on disk without changing its path.
`Threshold`	`int`	`get/set`	Minimum difference required for a pixel to count as foreground. [min=0, max=100, default=10]. Lower to catch subtle differences (more sensitive); raise to ignore camera noise and small lighting changes.
`Softness`	`int`	`get/set`	Width of the soft transition around matte edges. [min=0, max=100, default=20]. Raise for natural feathered edges; lower for crisper hard edges.
`PreBlur`	`int`	`get/set`	Smoothing applied before comparison to reduce sensitivity to noise. [min=0, max=10, default=0]. Raise if noisy footage is producing speckled edges; keep at 0 for clean, low-noise sources.
`DiffMode`	`DifferenceMode`	`get/set`	How the difference between frames is measured (RGB average, Luminance, Max Channel). Luminance is forgiving of slight colour shifts; Max Channel is most sensitive; RGB is balanced.
`RedTolerance`	`int`	`get/set`	Tolerance for red-channel differences. [min=0, max=50, default=0]. Raise to ignore small red shifts (e.g. warming light); lower to catch every difference.
`GreenTolerance`	`int`	`get/set`	Tolerance for green-channel differences. [min=0, max=50, default=0]. Raise to ignore small green shifts; useful when live lighting drifts slightly from the clean plate.
`BlueTolerance`	`int`	`get/set`	Tolerance for blue-channel differences. [min=0, max=50, default=0]. Raise to ignore small blue shifts (e.g. cooling light); lower to catch every difference.
`ExpandContract`	`int`	`get/set`	Grows or shrinks the matte. [min=-100, max=100, default=0]. Positive expands (good for catching halos); negative contracts (good for choking edges away from background bleed).
`Denoise`	`int`	`get/set`	Removes small isolated pixels (matte noise). [min=0, max=10, default=0]. Raise if the matte has speckles or stray pixels; keep at 0 for fine details like wisps of hair.
`OutMode`	`MatteOutputMode`	`get/set`	What to output (Composite, Matte Only, Foreground Only, Difference visualisation). Switch to Matte Only or Difference while tuning to inspect the matte; switch back to Composite for the final result.
`InvertMatte`	`bool`	`get/set`	Swap foreground and background regions of the matte. Use when you want to keep the static background and remove the moving subject instead.
`ShowCleanPlate`	`bool`	`get/set`	Show the loaded clean plate image as the operator output (for verification).
`Minilog`	`FormattedMessage`	`get/set`	Status message about clean plate loading and runtime warnings.

Inherits from: AbstractOperator, AbstractAudioMetering.

See also: Difference Matte in Operators — user-facing introduction, screenshots, and section summaries.