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Blur Color

ToolSets / Filter

Filter

2026-09-07

ToolSets/filter/blurColor.nk

blur

filter

lightness

CIE-LCH

color

utility

softening

View on GitHub

Blurs lightness in CIE-LCH after a LogC conversion while chroma and hue stay sharp. Single size control for Nuke.

Blur Color sends the image through AlexaV3LogC into CIE-LCH, blurs the lightness channel, then converts back. Chroma and hue are taken from the unblurred LCH image so only lightness is softened.

Use it when you need to reduce luminance detail without smearing color edges—beauty work, gentle CG softening, or any pass where hue fringing from a full blur would hurt.

Behavior is a straight filter: one input, one output, and a single size knob linked to the internal blur. No other controls are exposed.

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