Bm3d

Video Single output Transform

Block-Matching 3D denoiser.

FFmpeg filter: bm3d — the official reference.

Add it to a graph. The explicit form works for every filter — bind it to its inputs and read the result from outputs():

$node   = $video->addFilter(new Bm3d(…), [$other]);
$result = $node->outputs()[0];

Shorthand. Single-output filters can skip the node — apply() returns the result stream directly:

$result = $video->apply(new Bm3d(…), $other);

When to use it

TODO — when this filter shines: what it’s the right tool for, what to reach for instead when it isn’t, and how it composes with neighbouring filters.

How to use it

TODO — prose: how the filter actually works and what its key parameters mean (the explanation FFmpeg’s terse option help omits).

Examples

TODO — runnable PHP, with the equivalent ffmpeg CLI alongside.

Gotchas

TODO

See also

TODO

Parameters

Parameter	Type	Default	Range / values	Description
sigma	float	1	0–99999.9	set denoising strength
block	int	16	8–64	set size of local patch
bstep	int	4	1–64	set sliding step for processing blocks
group	int	1	1–256	set maximal number of similar blocks
range	int	9	≥ 1	set block matching range
mstep	int	1	1–64	set step for block matching
thmse	float	0	≥ 0	set threshold of mean square error for block matching
hdthr	float	2.7	≥ 0	set hard threshold for 3D transfer domain
estim	Bm3dMode	basic	basic, final	set filtering estimation mode
ref	bool	false	—	have reference stream
planes	int	7	0–15	set planes to filter

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Maps to FFmpeg’s bm3d filter. Verified against ffmpeg n7.1.1.