Split Horizontal and Vertical
Enables separate horizontal and vertical blur behavior.
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Blur & FocusBeginner
GaussianBlur
Smooth Gaussian image blur
Applies a smooth Gaussian blur with separate horizontal/vertical channel adjustments, border handling and mask support.
GaussianBlur
DaVinci Resolve · Fusion
Applies a smooth Gaussian blur with separate horizontal/vertical channel adjustments, border handling and mask support.
Overview
What GaussianBlur does
Applies a smooth Gaussian blur with separate horizontal/vertical channel adjustments, border handling and mask support.
GaussianBlur weights nearby pixels more strongly than distant ones, producing a smooth falloff that suits soft masks, text backplates, glow branches, shadows and background plates better than a hard box filter.
Split Horizontal and Vertical plus the channel controls let RGB and alpha be softened differently. At large radii, choose Border Type deliberately so the filter does not pull black into the frame edges.
Mental model
Unlike a box average, GaussianBlur weights nearby pixels more strongly toward the center, producing a smoother and more natural technical blur.
Common uses
Soften backgrounds
Blur masks and mattes
Reduce high-frequency detail
Prepare images for glow or displacement
Create gentle directional softness
Flow anatomy
Inputs & outputs
The port structure shows how this node fits into a Fusion graph.
Input
Source image for the operation.
Effect Mask
Optional mask that limits where the node affects the image.
GaussianBlur
Fusion node
Output
The processed result from this node.
Inspector
Important parameters
Start with these controls before reaching for more complicated workarounds.
Strength
Sets blur radius/strength.
Horizontal Channel Adjustment: Red
Sets Horizontal Channel Adjustment to Red.
Horizontal Channel Adjustment: Green
Sets Horizontal Channel Adjustment to Green.
Horizontal Channel Adjustment: Blue
Sets Horizontal Channel Adjustment to Blue.
Horizontal Channel Adjustment: Alpha
Sets Horizontal Channel Adjustment to Alpha.
Vertical Channel Adjustment: Red
Sets Vertical Channel Adjustment to Red.
Vertical Channel Adjustment: Green
Sets Vertical Channel Adjustment to Green.
Vertical Channel Adjustment: Blue
Sets Vertical Channel Adjustment to Blue.
Vertical Channel Adjustment: Alpha
Sets Vertical Channel Adjustment to Alpha.
Border Type
Defines edge handling: Black, Replicate, Reflect or Wrap-Around.
Border Type: Black
Sets Border Type to Black.
Border Type: Replicate
Sets Border Type to Replicate.
Border Type: Reflect
Sets Border Type to Reflect.
Border Type: Wrap-Around
Sets Border Type to Wrap-Around.
Effect Mask
Limits the blur spatially.
Practical setup
A reliable workflow
- 1
Connect the image.
- 2
Set a small Strength and increase gradually.
- 3
Split axes only when different X/Y blur is required.
- 4
Choose Reflect or Replicate if black borders appear.
- 5
Use a mask for localized softness.
Typical node chain
Input→
GaussianBlur→
Output
Examples
Where this node fits in real work
Background softening
Create a clean soft background behind a subject.
MediaInGaussianBlurMerge
Matte feathering
Smooth a generated matte before compositing.
BitmapGaussianBlurMatteControl
Troubleshooting
Common mistakes
Using Black border mode and creating dark contamination
Over-blurring alpha edges
Applying expensive blur where BoxBlur is sufficient
Forgetting that masks can limit the effect cleanly
Production notes
Practical tips
GaussianBlur is a good default when you want smooth rather than optical bokeh.
Keep edge handling in mind whenever the blur reaches the frame boundary.
Related nodes