Background Match

Sits a keyed foreground into the layer behind it, by matching that layer's levels and letting its light spill over the foreground's edges.

Property	Type	Access	Description
`ShowAdvancedOptions`	`bool`	`get/set`	Reveals the per-channel strengths of the levels match - Black Level, Mid Level and White Level. Leave it off for ordinary use: Amount alone is enough, and the three defaults are chosen so that the match does the right thing without them. Turn it on to bias the match toward one end of the range or to dial the mid-tone cast up and down. [default = No]
`SourceLayerMessage`	`FormattedMessage`	`get/set`	Which layer the operator is matching against. Read-only: the source is always the layer DIRECTLY ABOVE this one in the layer list, which is the layer immediately behind it in the composite - the same layer under either description.
`RefreshInterval`	`BackgroundRefreshInterval`	`get/set`	How often the background is re-measured and its light probe re-blurred.
`RefreshBackgroundCmd`	`Command`	`get/set`	Re-measure the background and rebuild its light probe now, without waiting for the next scheduled refresh. Useful when you have just changed the picture behind and want to see the match update against it straight away.
`RefreshMessage`	`FormattedMessage`	`get/set`	How long ago the background was last sampled. Counts up to the refresh interval and then resets, so it doubles as a sign that sampling is actually running.
`OutputMode`	`BackgroundMatchOutput`	`get/set`	Which stage of the operator to hand back instead of the finished picture. Every intermediate buffer the operator actually uses can be shown on its own - for setting the effect up, for diagnosing it, and so that a test can assert on one stage rather than on a composite in which anything could be responsible for a difference.
`WrapAmount`	`int`	`get/set`	Strength of the light wrap. 0 turns it off and costs nothing.
`WrapMaskMessage`	`FormattedMessage`	`get/set`	Whether a light wrap is being applied, and where its mask comes from.
`MatchAmount`	`int`	`get/set`	Strength of the whole levels match. 0 turns it off and skips both measurement passes. Defaults to off because it is a large colour change and should not happen unannounced the moment the operator is added to a layer. [default = 0]
`MatchBlackLevel`	`int`	`get/set`	How much of the background's black point to take. This is the atmospheric half of the match - lifting and tinting the shadows is what puts a subject into haze - and it is safe at full strength. [default = 100]
`MatchWhiteLevel`	`int`	`get/set`	How much of the background's white point to take. This is the end that crushes or blows out the highlights, so it usually wants far less than the black point. [default = 33]
`MatchMidLevel`	`int`	`get/set`	How much of the background's mid-tone colour to take. This is usually the control that does the work.
`ResetAllCmd`	`Command`	`get/set`	Return every setting to its default.

Inherits from: AbstractOperator, AbstractAudioMetering, NamedModel.

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