Blur Node

../../../_images/compositing_types_filter_blur-node_node.png

Blur Node.

The Blur node blurs an image, providing several blur modes.

Inputs

Image
Standard image input.
Size
The optional Size input will be multiplied with the X and Y blur radius values. It accepts also a value image, to control the blur radius with a mask. The values should be mapped between (0 to 1) for an optimal effect.

Properties

Type

The difference between the types is in the way they handle sharp edges, smooth gradients and preserve the highs and the lows.

Flat
Simply blurs everything uniformly.
Tent
Preserves the high and the lows better by making a linear falloff.
Quadratic
Looks similar to Gaussian but can be a little faster but slightly worse looking.
Cubic
Preserve the highs, but give an almost out-of-focus blur while smoothing sharp edges.
Gaussian
Gives the best looking results but tends to be the slowest.
Fast Gaussian
An approximation of the Gaussian.
Catmull-Rom
Catmull-Rom keeps sharp contrast edges crisp.
Mitch
Preserve the highs, but give an almost out-of-focus blur while smoothing sharp edges.
Variable Size

Allows a variable blur radius, if the size input is an image.

Bokeh
The Bokeh button will force the blur node to use a circular blur filter. This gives higher quality results, but is slower than using a normal filter.
Gamma
The Gamma button applies a gamma correction on the image before blurring it.
Relative

Percentage Value of the blur radius relative to the image size.

Aspect Correction
None, Y, X
X, Y
Values set the ellipsoid radius in numbers of pixels over which to spread the blur effect.
Extend Bounds
Allows the image, that is being blurred, to extend past its original dimension.

Outputs

Image
Standard image output.

Example

Blur node blur modes using 20% of image size as XY, no Bokeh/Gamma.
../../../_images/compositing_types_filter_blur-node_example-1-original.png

Original image.

../../../_images/compositing_types_filter_blur-node_example-2-flat.png

Flat.

../../../_images/compositing_types_filter_blur-node_example-3-tent.png

Tent.

../../../_images/compositing_types_filter_blur-node_example-4-quadratic.png

Quadratic.

../../../_images/compositing_types_filter_blur-node_example-5-cubic.png

Cubic.

../../../_images/compositing_types_filter_blur-node_example-6-gaussian.png

Gaussian.

../../../_images/compositing_types_filter_blur-node_example-7-fast-gaussian.png

Fast Gaussian.

../../../_images/compositing_types_filter_blur-node_example-8-catmull-rom.png

Catmull-Rom.

../../../_images/compositing_types_filter_blur-node_example-9-mitch.png

Mitch.

An example blend-file, in fact, the one used to create the image above, is available here. The blend-file takes one image from the Render Layer node “Blurs” and blurs it while offsetting it Translate and then combining it Alpha Over to build up the progressive sequence of blurs. Play with the Value and Multiply nodes to change the amount of blurring that each algorithm does.