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Blur

Node icon
Filter

Smooths an image with eight blur algorithms: Gaussian, Box, Median, Motion, Bilateral, Edge-Preserving, Radial, and Zoom.

The Blur node softens an image using one of eight algorithms. Gaussian is the standard all-purpose blur. Box is faster but lower quality. Median removes noise while preserving edges (great for salt-and-pepper noise). Motion simulates camera motion in a direction. Bilateral smooths flat areas while keeping edges sharp. Edge-Preserving is the most sophisticated, creating a painted, stylized look. Radial smears rotationally around a center point (set the Center X/Y and Spin Angle). Zoom smears toward or away from a center point (set the Center X/Y and Zoom Amount) for hyperspace and dolly-zoom effects.

The “Blur Alpha” toggle controls whether transparency is also blurred. Turn it off to soften the image while keeping sharp transparent edges, which is useful for sprites.

Parameters

Section titled “Parameters”

Pins

ImageImage
InputRequired
MaskMask
InputOptional
ImageImage
Output

Filter

TypeChoice
Default: Gaussian

Blur algorithm

  • GaussianThe standard smooth blur. Natural-looking falloff, good for most purposes.
  • BoxSimple averaging blur. Faster than Gaussian but with less natural falloff.
  • MedianReplaces each pixel with the median of its neighbors. Excellent for removing salt-and-pepper noise while keeping edges sharp.
  • MotionDirectional blur that simulates camera movement. Set the angle and distance.
  • BilateralSmooths flat areas while preserving edges. Great for skin retouching and noise reduction without losing detail.
  • Edge PreserveCreates a painted, stylized look while keeping important edges intact.
  • RadialRotational smear around a center point. Use Spin Angle to control the arc.
  • ZoomRadial smear toward or away from a center point. Use Zoom Amount to control the streak length.
RadiusNumber · px/%
Default: 5.0 Range: 0.0–200.0 px / 0–100%
Gaussian / Box / Median only

Blur strength. 0 = no blur, higher = more blur

Blur AlphaToggle
Default: false

Also blur the alpha channel. Uncheck to preserve sharp transparency edges

AngleNumber
Default: 0.0 Range: 0.0–360.0
Motion only

Direction of motion blur in degrees. 0 = horizontal right

DistanceInteger · px/%
Default: 20 Range: 1–500 px / 0–100%
Motion only

Motion streak length. Higher = longer motion trail

DiameterInteger
Default: 9 Range: 1–15
Bilateral only

Neighborhood diameter. Smaller = faster, less smoothing

Color ThresholdNumber
Default: 75 Range: 10–150
Bilateral only

How similar colors must be to blur together

SpreadNumber
Default: 75 Range: 10–150
Bilateral only

How far the smoothing reaches

AlgorithmChoice
Default: 0 Range: Recursive / Norm. Conv.
Edge Preserve only

Recursive: faster. Normalized Convolution: smoother results

SmoothnessNumber
Default: 60 Range: 1–200
Edge Preserve only

How much the image is smoothed

SimplifyNumber
Default: 0.40 Range: 0.01–1.00
Edge Preserve only

How much detail is flattened. Lower = more detail preserved

Center X (%)Number
Default: 50.0 Range: 0.0–100.0
Radial / Zoom only

Horizontal blur center

Center Y (%)Number
Default: 50.0 Range: 0.0–100.0
Radial / Zoom only

Vertical blur center

Spin AngleNumber
Default: 15.0 Range: 0.0–180.0
Radial only

Total rotation arc to smear over, in degrees. 0 = no blur, 180 = half-rotation smear

Zoom Amount (%)Number
Default: 5.0 Range: 0.0–100.0
Zoom only

Strength of the radial smear

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 — 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”
  • Bilateral blur is great for skin smoothing because it removes noise while keeping edge detail.
  • Use a small Gaussian blur (1–3) before Edge Detect for cleaner results.
  • Motion blur with a large distance creates dramatic speed lines.
  • Radial blur with a small Spin Angle adds gentle camera shake; large angles create vortex effects around the center.
  • Zoom blur is great for hyperspace, speed, and dramatic focal-point emphasis. Drag the center off the image for off-screen zooms.
  • Uncheck Blur Alpha when working with game sprites to keep crisp silhouettes.
  • Connect a mask input to blur only specific regions, such as selective focus or privacy blurring.
Section titled “Related Nodes”