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Levels

Node icon
Color

Adjusts the tonal range with input/output levels and gamma, per-channel or master.

Levels is a fundamental tonal adjustment. The input range clips shadows (Input Black) and highlights (Input White), compressing the tonal range. Gamma adjusts midtones: values below 1.0 darken, above 1.0 brighten. The output range then remaps the result to a new brightness window.

Each channel (Red, Green, Blue, Alpha) can be adjusted independently, or use Master to adjust all at once. The histogram shows the image’s current tonal distribution.

Parameters

Section titled “Parameters”

Color

ChannelChoice
Default: Master

Channel to adjust

  • MasterAdjust all RGB channels together — affects overall brightness and contrast.
  • RedAdjust only the red channel — affects red/cyan color balance.
  • GreenAdjust only the green channel — affects green/magenta color balance.
  • BlueAdjust only the blue channel — affects blue/yellow color balance.
  • AlphaAdjust the alpha (transparency) channel — affects opacity levels.
Show HistogramToggle
Default: true

Display histogram visualization

Input BlackNumber
Default: 0.0 Range: 0.0–1.0

Shadow clipping; pixels at or below become Output Black

Input WhiteNumber
Default: 1.0 Range: 0.0–1.0

Highlight clipping; pixels at or above become Output White

GammaNumber
Default: 1.0 Range: 0.01–9.99

Midtone correction; <1 darkens, >1 brightens

Output BlackNumber
Default: 0.0 Range: 0.0–1.0

Darkest output value after adjustment

Output WhiteNumber
Default: 1.0 Range: 0.0–1.0

Brightest output value after 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

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

Usage Tips

Section titled “Usage Tips”
  • Drag Input Black right to clip dark noise; drag Input White left to boost dim highlights.
  • Use Output Black > 0 to lift the shadows (no pure black) for a faded/matte look.
  • Adjust individual channels to correct color casts. For example, reduce Input White on Blue to warm up an image.
  • Connect a mask input to apply the tonal adjustment to only part of the image.
Section titled “Related Nodes”