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Curves

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Color

Fine-tune tonality with bezier curve adjustments per channel. The most precise tonal control available.

Curves provides per-channel tonal adjustment using a bezier spline. Each point on the curve maps an input brightness to an output brightness. The Master channel affects all RGB channels; individual R, G, B channels adjust colors independently.

Curves gives you more precise control than Levels because you can target specific tonal ranges (like just the quarter-tones or three-quarter-tones) that Levels can’t address.

Parameters

Section titled “Parameters”

Color

ChannelChoice
Default: Master

Active channel

  • MasterAdjust all RGB channels together with a single curve.
  • RedAdjust only the red channel curve.
  • GreenAdjust only the green channel curve.
  • BlueAdjust only the blue channel curve.
Master curvejson-array
Default: [[0,0],[255,255]] Range: [x,y] 0–255

Master tonal adjustment spline

Red curvejson-array
Default: [[0,0],[255,255]] Range: [x,y] 0–255

Red channel tonal adjustment

Green curvejson-array
Default: [[0,0],[255,255]] Range: [x,y] 0–255

Green channel tonal adjustment

Blue curvejson-array
Default: [[0,0],[255,255]] Range: [x,y] 0–255

Blue channel tonal adjustment

Mask

Mask FitChoice
Default: None

Mask sizing

  • NoneCenter the mask at its native size — no resizing. Unmasked regions are unaffected.
  • StretchStretch the mask to exactly match the image dimensions. May distort the mask shape.
  • FitScale the mask to fit inside the image, preserving aspect ratio. Letterboxes where needed.
  • FillScale the mask to fill the image, preserving aspect ratio. Crops edges if aspect ratios differ.
Notes

Mask Fit only visible when mask is connected.

Pins: image (required), mask (optional). When mask is connected, the curve effect is blended with the original using the mask (white = full effect, black = original).

Usage Tips

Section titled “Usage Tips”
  • An S-curve (lift shadows, push highlights) is the classic contrast boost.
  • Pull the bottom-left point up to lift shadows for a matte/faded look.
  • Use individual channel curves to create cross-process or film emulation effects.
  • Double-click or Ctrl+click on the curve to add control points. Right-click or Alt+click a point to remove it.
  • Connect a mask input to apply the curve adjustment to only part of the image.
Section titled “Related Nodes”