title: GradeOFX
media types:
Video experimental
description: Modify the tonal spread of an image from the white and black points.
This node can also be used to match colors of 2 images: The darkest and lightest points of the target image are converted to black and white using the blackpoint and whitepoint values. These 2 values are then moved to new values using the black(for dark point) and white(for white point). You can also apply multiply/offset/gamma for other color fixing you may need.
Here is the formula used:
A = multiply * (white - black) / (whitepoint - blackpoint)
B = offset + black - A * blackpoint
output = pow(A * input + B, 1 / gamma).
A special use for Grade is to generate a mask image with soft edges by thresholding an input image. Set the "Black Point" and "White Point" to values just below and just above the threshold, and check the "Clamp Black" and "Clamp White" options. If a binary mask containing only 0 and 1 is preferred, the Clamp plugin can be used instead.
See also: https://web.archive.org/web/20220627014345/http://www.opticalenquiry.com/nuke/index.php?title=Grade and https://web.archive.org/web/20210728000722/http://opticalenquiry.com/nuke/index.php?title=Integration#Matching_colorr
version: 2
creator: mr.fantastic mrfantastic@firemail.cc
license: GPLv2
URL: https://openeffects.org/
title: R
description:
Process red channel.
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: G
description:
Process green channel.
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: B
description:
Process blue channel.
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: A
description:
Process alpha channel.
type: boolean
readonly: no
required: no
animation: yes
default: 0
title: Black Point
description:
Set the color of the darkest pixels in the image.
type: color
readonly: no
required: no
animation: yes
default: #00000000
widget: color
title: White Point
description:
Set the color of the brightest pixels in the image.
type: color
readonly: no
required: no
animation: yes
default: #FFFFFFFF
widget: color
title: Lift
description:
Colors corresponding to the blackpoint are set to this value.
type: color
readonly: no
required: no
animation: yes
default: #00000000
widget: color
title: Gain
description:
Colors corresponding to the whitepoint are set to this value.
type: color
readonly: no
required: no
animation: yes
default: #FFFFFFFF
widget: color
title: Multiply
description:
Multiplies the result by this value.
type: color
readonly: no
required: no
animation: yes
default: #FFFFFFFF
widget: color
title: Offset
description:
Adds this value to the result (this applies to black and white).
type: color
readonly: no
required: no
animation: yes
default: #00000000
widget: color
title: Gamma
description:
Final gamma correction. Negative values are not affected by gamma.
type: color
readonly: no
required: no
animation: yes
default: #FFFFFFFF
widget: color
title: Reverse
description:
Apply the inverse correction. Useful to apply the inverse of a Grade downstream: copy-and-paste or clone the upstream node, and invert the downstream one.
type: boolean
readonly: no
required: no
animation: yes
default: 0
title: Clamp Black
description:
All colors below 0 on output are set to 0.
type: boolean
readonly: no
required: no
animation: yes
default: 1
title: Clamp White
description:
All colors above 1 on output are set to 1.
type: boolean
readonly: no
required: no
animation: yes
default: 0
title: (Un)premult
description:
Divide the image by the alpha channel before processing, and re-multiply it afterwards. Use if the input images are premultiplied.
type: boolean
readonly: no
required: no
animation: yes
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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