11.40. ITK H Minima Image Filter

Fills shallow dark valleys by suppressing local minima whose depth is less than h.

Group (Subgroup)

ITKMathematicalMorphology (MathematicalMorphology)

Description

The H-Minima transform removes insignificant dark dips from a grayscale image. Any local minimum that lies less than h below its local background is filled in — raised to an estimate of that background — while deeper, genuine valleys are preserved. This smooths over the “low” parts of the noise without blurring real region boundaries or large intensity changes.

Use this filter to clean up dark speckle and spurious low spots before segmentation, or as a preconditioning step for minima detection (for example to control over-segmentation in a watershed). It is the dark-feature counterpart of the H Maxima filter; the matching operation that extracts prominent bright peaks is the H Convex filter.

Parameter Guidance

  • Height — the depth h, in the input image’s intensity units. Minima that lie less than h below their local background are filled; valleys deeper than h survive. Larger values fill more dips. Default 2.0.

  • Fully Connected — controls pixel connectivity. When off (default), neighbors share a face; when on, neighbors also include edge- and corner-touching pixels. Turn it on for thin, one-pixel-wide features.

Required Input Sources

Operates on any scalar 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

Height

Scalar Value

Float64

Set/Get the height that a local maximum must be above the local background (local contrast) in order to survive the processing. Local maxima below this value are replaced with an estimate of the local background.

Fully Connected

Bool

Set/Get whether the connected components are defined strictly by face connectivity or by face+edge+vertex connectivity. Default is FullyConnectedOff. For objects that are 1 pixel wide, use FullyConnectedOn.

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

DREAM3D-NX Help

If you need help, need to file a bug report or want to request a new feature, please head over to the DREAM3DNX-Issues GitHub site where the community of DREAM3D-NX users can help answer your questions.