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Brightness/Contrast

Brightness/Contrast
Color

Simple brightness and contrast adjustment with two modes: S-Curve for smooth results or Linear for classic gain.

Brightness/Contrast is the fastest way to make an image brighter, darker, or punchier. Brightness shifts the overall tone up or down, and Contrast controls the separation between lights and darks.

S-Curve mode (default) uses a sigmoid function that gently rolls off highlights and shadows, producing natural results without harsh clipping. Linear mode uses simple gain around the midpoint. It is more aggressive and clips sooner at the extremes.

Parameters

Section titled “Parameters”

Pins

ImagePixels
InputRequired
MaskMask
InputOptional
ImagePixels
Output

Adjust

ModeChoice
Default: S-Curve
  • S-CurveSmooth sigmoid contrast that boosts midtone separation while gently rolling off highlights and shadows.
  • LinearClassic gain around midpoint. More aggressive, and clips at extremes.
BrightnessNumber
Default: 0.0 Range: -100.0–100.0

Brightness offset. Positive brightens, negative darkens

ContrastNumber
Default: 0.0 Range: -100.0–100.0

Contrast gain around midpoint. Positive increases, negative decreases

Mask

Mask FromChoice
Default: Luminance
Color image connected to the mask input

How the connected color image is read as a mask. Luminance: the image's brightness. Alpha: the image's transparency. Red / Green / Blue: a single channel

  • LuminanceRead the image's brightness as the mask. The default.
  • AlphaRead the image's transparency as the mask.
  • RedUse the red channel as the mask.
  • GreenUse the green channel as the mask.
  • BlueUse the blue channel as the mask.
Mask FitChoice
Default: None (native size)
Mask connected

How the mask is sized when it doesn't match the image. None: center at native size, no scaling. Stretch: scale to exactly match image dimensions. Fit: scale to fit inside image, preserving aspect ratio. Fill: scale to fill image, cropping overflow

  • None (native size)Center the mask at its native size, with no resizing. Unmasked regions are unaffected.
  • StretchStretch the mask to exactly match the image dimensions. May distort the mask shape.
  • Fit (letterbox)Scale the mask to fit inside the image, preserving aspect ratio. Letterboxes where needed.
  • Fill (crop)Scale the mask to fill the image, preserving aspect ratio. Crops edges if aspect ratios differ.

Usage Tips

Section titled “Usage Tips”
  • Use S-Curve mode (default) for most work, as it produces more natural results than Linear.
  • In S-Curve mode (the default), brightness is applied before contrast, so a small brightness boost followed by a contrast increase can bring out midtone detail.
  • For more precise tonal control, use Levels or Curves instead.
  • Connect a mask input to limit the adjustment to specific regions of the image.
Section titled “Related Nodes”