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Blur Color

ToolSets / Filter

Filter

2026-09-07

ToolSets/filter/blurColor.nk

filter

blur

colorspace

lch

lightness

logc

utility

View on GitHub

Blurs Lightness in CIE-LCH after an AlexaV3LogC conversion, keeping chroma and hue sharp. Single size control.

Blur Color converts the input to AlexaV3LogC, then to CIE-LCH. It blurs that image, copies the blurred red channel onto the unblurred stream, and converts back through CIE-LCH and AlexaV3LogC. In CIE-LCH, RGB carries Lightness, Chroma, and Hue, so only Lightness is softened.

Use it when a straight RGB blur is too uniform across channels and you want softness on luminance-like detail while chroma and hue stay sharp. The colorspace path is fixed inside the Group.

Size is the only exposed control and drives the internal Blur. The result returns through the inverse conversions so the node can sit inline in a comp.

Script code

version 10.5 v6
push $cut_paste_input
Group {
 name blurColor
 tile_color 0x421010ff
 selected true
 xpos 1385
 ypos -4220
 addUserKnob {20 User l blurColor}
 addUserKnob {41 size T Blur1.size}
 addUserKnob {26 ""}
 addUserKnob {26 lbl l "" +STARTLINE T "Blur Color v1.0"}
 addUserKnob {22 btn l DerekVFX.ca T "nuke.tcl('start', 'https://derekvfx.ca')" +STARTLINE}
}
 Input {
  inputs 0
  name Input
  xpos 447
  ypos 61
 }
 Colorspace {
  colorspace_out AlexaV3LogC
  name Colorspace1
  label "\[value colorspace_in] - \[value colorspace_out]"
  xpos 447
  ypos 171
 }
 Colorspace {
  colorspace_out CIE-LCH
  name Colorspace3
  label "\[value colorspace_in] - \[value colorspace_out]"
  xpos 441
  ypos 243
 }
set Nfc93820 [stack 0]
push $Nfc93820
 Blur {
  channels rgba
  name Blur1
  label "\[value size] px"
  xpos 335
  ypos 301
 }
 Copy {
  inputs 2
  from0 rgba.red
  to0 rgba.red
  name Copy1
  xpos 441
  ypos 339
 }
 Colorspace {
  colorspace_in CIE-LCH
  name Colorspace4
  label "\[value colorspace_in] - \[value colorspace_out]"
  xpos 447
  ypos 385
 }
 Colorspace {
  colorspace_in AlexaV3LogC
  name Colorspace2
  label "\[value colorspace_in] - \[value colorspace_out]"
  xpos 447
  ypos 472
 }
set N17b32900 [stack 0]
push $N17b32900

 Output {
  name Output1
  xpos 447
  ypos 1055
 }
end_group