11.56. ITK Morphological Gradient Image Filter
Highlights edges in a grayscale image by subtracting a local minimum-filtered image from a local maximum-filtered image.
Group (Subgroup)
ITKMathematicalMorphology (MathematicalMorphology)
Description
The morphological gradient is an edge detector. At each pixel it computes the difference between a grayscale dilation (the maximum value in the neighborhood defined by the structuring element) and a grayscale erosion (the minimum value in that same neighborhood):
morphological gradient = dilation − erosion
Where the image is flat, the local maximum and minimum are nearly equal and the result is near zero (dark). Where intensity changes sharply — an edge — the maximum and minimum differ greatly and the result is large (bright). The output is therefore bright along object boundaries and dark in uniform regions. The width of the detected edges grows with the size of the structuring element.
Parameter Guidance
Kernel Radius — the radius of the structuring element, in pixels (one value per axis). Larger radii detect broader edges.
Kernel Type
The Kernel Type parameter selects the structuring element shape:
Annulus [0]: A ring-shaped structuring element.
Ball [1]: A spherical structuring element (default). Most commonly used for general morphological operations.
Box [2]: A rectangular/cuboid structuring element.
Cross [3]: A cross-shaped structuring element.
Required Input Sources
Operates on any scalar (grayscale) image — typically from Read Image, Read Images [3D Stack], or the output of a prior ITK image filter.
Input Parameter(s)
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Kernel Radius |
Vector of UInt32 Values |
Order=X,Y,Z |
The radius of the kernel structuring element. |
Kernel Type |
Choices |
Set the kernel or structuring element used for the morphology. |
Input Cell Data
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Image Geometry |
Geometry Selection |
Image |
Select the Image Geometry Group from the DataStructure. |
Input Cell Data |
Array Selection |
Allowed Types: int8, uint8, int16, uint16, int32, uint32, int64, uint64, float32, float64 |
The image data that will be processed by this filter. |
Output Cell Data
Parameter Name |
Parameter Type |
Parameter Notes |
Description |
|---|---|---|---|
Output Cell Data |
DataObjectName |
The result of the processing will be stored in this Data Array inside the same group as the input data. |
Example Pipelines
License & Copyright
Please see the description file distributed with this Plugin
DREAM3D-NX Help
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