title: MatteOFX
media types:
Video experimental
description: Pixel-by-pixel merge operation between two or more inputs.
Input A is first merged with B (or with a black and transparent background if B is not connected), then A2, if connected, is merged with the intermediary result, then A3, etc.
A description of most operators is available in the W3C Compositing and Blending Level 1 Recommendation https://www.w3.org/TR/compositing-1/ and a complete explanation of the Porter-Duff compositing operators can be found in "Compositing Digital Images", by T. Porter and T. Duff (Proc. SIGGRAPH 1984) http://keithp.com/~keithp/porterduff/p253-porter.pdf
Note that if an input with only RGB components is connected to A or B, its alpha channel is considered to be opaque (one) by default, thus the output will be completely opaque if the checkbox for channel A of input B is checked. One reason for this behaviour is that non-zero RGB values with a zero A value are not valid alpha-premultiplied RGBA values. If the user wishes to keep the background fully transparent, it can only be black, which is equivalent to not using the merge operator. Non-black fully transparent pixels should never appear anywhere in a proper compositing graph.
See also:
version: 2
creator: mr.fantastic mrfantastic@firemail.cc
license: GPLv2
URL: https://openeffects.org/
title: Operation
description:
The operation used to merge the input A and B images.
The operator formula is applied to each component: A and B represent the input component (Red, Green, Blue, or Alpha) of each input, and a and b represent the alpha channel of each input.
If Alpha masking is checked, the output alpha is computed using a different formula (a+b - a*b).
Alpha masking is always enabled for HSL modes (hue, saturation, color, luminosity).
type: string
readonly: no
required: no
animation: yes
default: matte
values:
title: Bounding Box
description:
What to use to produce the output image's bounding box.
type: string
readonly: no
required: no
animation: yes
default: Union
values:
title: Alpha masking
description:
When enabled, the input images are unchanged where the other image has 0 alpha, and the output alpha is set to a+b - a*b. When disabled the alpha channel is processed as any other channel. Option is disabled for operations where it does not apply or makes no difference.
type: boolean
readonly: no
required: no
animation: yes
default: 0
description:
Channels to use from A input(s) (other channels are set to zero).
type: string
readonly: yes
required: no
animation: yes
default: A Channels
title: R
description:
Use red channel from A input(s).
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: G
description:
Use green channel from A input(s).
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: B
description:
Use blue channel from A input(s).
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: A
description:
Use alpha channel from A input(s).
type: boolean
readonly: no
required: no
animation: yes
default: 1
description:
Channels to use from B input (other channels are set to zero).
type: string
readonly: yes
required: no
animation: yes
default: B Channels
title: R
description:
Use red channel from B input.
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: G
description:
Use green channel from B input.
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: B
description:
Use blue channel from B input.
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: A
description:
Use alpha channel from B input.
type: boolean
readonly: no
required: no
animation: yes
default: 1
description:
Channels from result to write to output (other channels are taken from B input).
type: string
readonly: yes
required: no
animation: yes
default: Output
title: R
description:
Write red channel to output.
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: G
description:
Write green channel to output.
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: B
description:
Write blue channel to output.
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: A
description:
Write alpha channel to output.
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: Invert Mask
description:
When checked, the effect is fully applied where the mask is 0.
type: boolean
readonly: no
required: no
animation: yes
title: Mix
description:
Mix factor between the original and the transformed image.
type: float
readonly: no
required: no
animation: yes
minimum: 0
maximum: 1
default: 1
title: Top-Left Origin
description:
Set to 1 to use MLT top-left image origin instead of the OFX bottom-left origin. Use for plugins that crash or produce incorrect output with negative row bytes.
type: boolean
readonly: no
required: no
minimum: 0
maximum: 1
default: 0
widget: checkbox
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