Dilate/Erode Node¶
Expands or shrinks a mask using a morphological operator.
Inputs¶
- Mask
A grayscale image.
Properties¶
- Mode
- Steps
Sets each pixel to the maximum (for dilation) or minimum (for erosion) value that’s found within a square surrounding it. This approach keeps the original gray levels and is best suited for masks that contain sharp corners; rounded shapes such as circles will look more square-like in the output.
Despite the name, this is not an iterative process; the dilation/erosion is only performed once regardless of the chosen Distance.
- Threshold
Makes all the pixels fully black or white depending on whether they’re darker or brighter than 50% gray. Then, sets each pixel to the maximum (for dilation) or minimum (for erosion) value that’s found within a circle surrounding it. This approach loses the original gray levels. Shape wise, it’s well-suited for masks that contain rounded corners; sharp ones will be rounded off.
- Distance
Sets each pixel to the maximum (for dilation) or minimum (for erosion) value that’s found within a circle surrounding it. This approach preserves the original gray levels and is well-suited for masks that contain rounded corners.
- Feather
Blurs the image.
- Distance
The size of the surrounding area to look at for each pixel; or in other words, how much to dilate (for positive values) or erode (for negative values) the mask.
- Edge
For the Threshold mode, determines how much to blur the edges after dilation/erosion.
- Falloff
For the Feather mode, determines the brightness curve of the blurred edges.
Outputs¶
- Mask
The resulting mask.
Example¶
In the image below, notice that:
The light gray disk has turned white and the dark gray rectangle has turned black because of the Threshold mode.
The shapes have become thicker – dilated because of the positive Distance.
The shapes appear blurred because of the positive Edge.
