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Local Contrast

Node icon
Color

Enhances local detail and clarity using CLAHE (Contrast Limited Adaptive Histogram Equalization).

The Local Contrast node applied to a source image: original (left) and result (right).
Side-by-side comparison: the original image on the left and the same image after the Local Contrast node on the right.

Unlike global Levels or Curves, Local Contrast divides the image into a grid of tiles (Columns and Rows, in the Tile Grid section) and equalizes each tile’s histogram on its own, bringing out texture in shadows and highlights at once.

Parameters

Section titled “Parameters”

Pins

ImagePixels
InputRequired
MaskMask
InputOptional
ImagePixels
Output

Enhancement

Clip LimitNumber
Default: 2.0 Range: 1.0–40.0

Contrast amplification limit. Higher = stronger local contrast boost, lower = subtler enhancement.

Values above 10 may introduce noise.

Tile Grid

ColumnsInteger
Default: 8 Range: 2–128

Horizontal tile grid size. Smaller = more localized enhancement, larger = broader, more global adjustment

RowsInteger
Default: 8 Range: 2–128

Vertical tile grid size. Smaller = more localized enhancement, larger = broader, more global adjustment

Mask

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

How the connected color image is read as a mask

  • 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 (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”
  • A Clip Limit of 2 to 4 gives subtle clarity without artifacts.
  • Use it after Denoise to restore detail that denoising softened.
  • Connect a mask input to enhance detail in specific regions only.
Section titled “Related Nodes”