User Manual

Inspector
Controls Tab
The Controls tab includes the main Amount slider that determines whether you are performing
an erode by entering a negative value or a dilate by entering a positive value.
Color Channels (RGBA)
The Erode Dilate node defaults to operating on R, G, B, and A channels. Selective channel
editing is possible by enabling or disabling the checkboxes beside each channel.
This is not the same as the RGBA checkboxes found under the Common Controls. The node
takes these controls into account before it processes. Deselecting a channel causes the node
to skip that channel when processing, speeding up the rendering of the effect. In contrast, the
channel controls under the Common Controls tab are applied after the node has processed.
Lock X/Y
The Lock X/Y checkbox is used to separate the Amount slider into amount X and amount Y,
allowing a different value for the effect on each axis.
Amount
A negative value for Amount causes the image to erode. Eroding simulates the effect of an
underexposed frame, shrinking the image by growing darker areas of the image so that they eat
away at brighter regions.
A positive value for Amount causes the image to dilate, similar to the effect of overexposing a
camera. Regions of high luminance and brightness grow, eating away at the darker regions of
the image. Both techniques eradicate fine detail in the image and tend to posterize fine
gradients.
The Amount slider scale is based on the input image width. An amount value of 1 = image width.
So, if you want to erode or dilate by exactly 1 pixel on an HD image, you would enter 1/1920, or
0.00052083.
Common Controls
Settings Tab
The Settings tab controls are common to all Filter nodes, so their descriptions can be found in
“The Common Controls” section at the end of this chapter.
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