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Robust Automatic Threshold

Group (Subgroup)

DREAM3D Review (Threshold)


This Filter automatically computes a threshold value for a scalar Attribute Array based on the array's gradient magnitude, producing a boolean array that is false where the input array is less than the threshold value and true otherwise. The threshold value is computed using the following equation:

\f[ T = \sum_{i = 1}^{n} \frac{a_{i} g_{i}}{g_{i}} \f]

where \f$ a \f$ is the input array, \f$ g \f$ is the gradient magnitude array, \f$ n \f$ is the length of the input array, and \f$ T \f$ is the computed threshold value. Computing a threshold in this manner will generally partition the input array where its gradient is highest. Gradients may be computed using the Find Derivatives Filter. The gradient magnitude may then be found by computing the 2-norm of the gradient.



Required Geometry


Required Objects

Kind Default Name Type Component Dimensions Description
Any Attribute Array None Any except bool (1) Attribute Array to threshold
Attribute Array None float (1) Gradient magnitude of input Attribute Array

Created Objects

Kind Default Name Type Component Dimensions Description
Attribute Array Mask bool (1) Mask array produced after application of the computed robust threshold to the input Attribute Array

Example Pipelines

Please see the description file distributed with this plugin.

DREAM3D Mailing Lists

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