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Posterize

Node icon
Color

Reduces the number of color levels for a flat, stylized look, with optional dithering.

The Posterize 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 Posterize node on the right.

Posterize reduces the number of distinct values each channel can have. At 8 levels, you get the classic poster/pop-art effect. At 2 levels, each channel is binary (on/off). Higher values create subtler banding.

Per-channel mode lets you set different level counts for R, G, and B independently. Dithering adds a subtle pattern to reduce visible banding.

Parameters

Section titled “Parameters”

Pins

ImagePixels
InputRequired
MaskMask
InputOptional
ImagePixels
Output

Color

LevelsInteger
Default: 32 Range: 2–256
When Per Channel is off

Distinct values per R, G, B channel, applied independently to each channel. Total unique colors can reach levels cubed (2 = up to 8, 4 = up to 64).

  • 8: the classic poster effect.
  • 256: no change (passthrough).
Per ChannelToggle
Default: false

Enable separate level controls for Red, Green, and Blue.

Off: all channels use the same number of levels.

Red LevelsInteger
Default: 32 Range: 2–256
When Per Channel is on

Distinct values for the red channel. 2 = on/off, 256 = unchanged.

Green LevelsInteger
Default: 32 Range: 2–256
When Per Channel is on

Distinct values for the green channel. 2 = on/off, 256 = unchanged.

Blue LevelsInteger
Default: 32 Range: 2–256
When Per Channel is on

Distinct values for the blue channel. 2 = on/off, 256 = unchanged.

DitherToggle
Default: false

Apply ordered (Bayer 4x4) dithering to reduce visible banding between color levels.

Creates a stippled pattern that simulates more colors than the level count allows.

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”
  • Low levels (2–4) create bold graphic effects; 8–16 creates subtle stylization.
  • Enable dithering to smooth out color transitions at low level counts.
  • Combine with Quantize for even more control over the final palette.
  • Connect a mask input to posterize only specific regions, useful for selective stylization.
Section titled “Related Nodes”