Package gov.nih.mipav.model.algorithms.levelset

Class LsePdeFilter

java.lang.Object
gov.nih.mipav.model.algorithms.levelset.LsePdeFilter
Direct Known Subclasses:
LsePdeFilter2, LsePdeFilter3
public abstract class LsePdeFilter extends Object
The abstract base class for finite-difference-based solvers for partial differential equations. This system exists to support level-set evolution for image segmentation.
Version:
0.1 November 7, 2006
Author:
David Eberly

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected int
    m_eScaleType
    The type of image scaling used during filter construction.
    protected float
    m_fBorderValue
    When set to Float.MAX_VALUE, Neumann conditions are in use (zero-valued derivatives on the image border).
    protected float
    m_fMin
    The minimum image value.
    protected float
    m_fOffset
    The offset used in scaling the image data.
    protected float
    m_fScale
    The scale factor used in scaling the image data.
    protected float
    m_fTimeStep
    The time step for the PDE solver.
    protected int
    m_iQuantity
    The number of image elements.
    static final int
    NONE
    Scale type: no scaling.
    static final int
    PRESERVE_ZERO
    Scale type: max > -min: d' = d/max in [min/max,1] max invalid input: '<' -min: d' = -d/min in [-1,-max/min]
    static final int
    SYMMETRIC
    Scale type: d' = -1 + 2*(d-min)/(max-min) in [-1,1]
    static final int
    UNIT
    Scale type: d' = (d-min)/(max-min) in [0,1]

  • Constructor Summary

    Constructors
    Modifier
    Constructor
    Description
    protected
    LsePdeFilter(int iQuantity, float[] afData, float fBorderValue, int eScaleType)
    Creates a new PDE filter object.

  • Method Summary

    Modifier and Type
    Method
    Description
    final float
    getBorderValue()
    Get the image border value.
    final int
    getQuantity()
    Get the number of image elements.
    final int
    getScaleType()
    Get the type of image scaling.
    final float
    getTimeStep()
    Get the time step for the PDE solver.
    protected abstract void
    onPostUpdate()
    An abstract function that allows derived classes to implement any desired behavior after the PDE solver applies its update function.
    protected abstract void
    onPreUpdate()
    An abstract function that allows derived classes to implement any desired behavior before the PDE solver applies its update function.
    protected abstract void
    onUpdate()
    An abstract function for the update function of the PDE solver.
    final void
    setTimeStep(float fTimeStep)
    Set the time step for the PDE solver.
    void
    update()
    The entry point to updating the PDE solver.

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • NONE

      public static final int NONE
      Scale type: no scaling.
      See Also:

    • UNIT

      public static final int UNIT
      Scale type: d' = (d-min)/(max-min) in [0,1]
      See Also:

    • SYMMETRIC

      public static final int SYMMETRIC
      Scale type: d' = -1 + 2*(d-min)/(max-min) in [-1,1]
      See Also:

    • PRESERVE_ZERO

      public static final int PRESERVE_ZERO
      Scale type: max > -min: d' = d/max in [min/max,1] max invalid input: '<' -min: d' = -d/min in [-1,-max/min]
      See Also:

    • m_iQuantity

      protected int m_iQuantity
      The number of image elements.

    • m_fBorderValue

      protected float m_fBorderValue
      When set to Float.MAX_VALUE, Neumann conditions are in use (zero-valued derivatives on the image border). Dirichlet conditions are used, otherwise (image is constant on the border).

    • m_eScaleType

      protected int m_eScaleType
      The type of image scaling used during filter construction.

    • m_fMin

      protected float m_fMin
      The minimum image value.

    • m_fOffset

      protected float m_fOffset
      The offset used in scaling the image data.

    • m_fScale

      protected float m_fScale
      The scale factor used in scaling the image data.

    • m_fTimeStep

      protected float m_fTimeStep
      The time step for the PDE solver. The stability of an algorithm depends on the magnitude of the time step but the magnitude itself depends on the algorithm.

  • Constructor Details

    • LsePdeFilter

      protected LsePdeFilter(int iQuantity, float[] afData, float fBorderValue, int eScaleType)
      Creates a new PDE filter object.
      Parameters:
      iQuantity - The number of image elements.
      afData - The image elements, stored in lexicographical order.
      fBorderValue - Specifies how to handle the image value. When set to Float.MAX_VALUE, Neumann conditions are in use, in which case zero-valued derivatives are assumed on the image border. Otherwise, Dirichlet conditions are used, in which case the image is assumed to be constant on the border with value specified by fBorderValue.
      eScaleType - The type of scaling to apply to the input image. The choices are NONE, UNIT, SYMMETRIC, or PRESERVE_ZERO.

  • Method Details

    • getQuantity

      public final int getQuantity()
      Get the number of image elements.
      Returns:
      The number of image elements.

    • getBorderValue

      public final float getBorderValue()
      Get the image border value.
      Returns:
      The image border value.

    • getScaleType

      public final int getScaleType()
      Get the type of image scaling.
      Returns:
      The type of image scaling.

    • setTimeStep

      public final void setTimeStep(float fTimeStep)
      Set the time step for the PDE solver.
      Parameters:
      fTimeStep - The time step for the PDE solver. It must be a positive number. Its maximum-allowed size depends on the specific algorithm.

    • getTimeStep

      public final float getTimeStep()
      Get the time step for the PDE solver.
      Returns:
      The time step for the PDE solver.

    • update

      public void update()
      The entry point to updating the PDE solver. This function calls OnPreUpdate, OnUpdate, and OnPostUpdate, in that order.

    • onPreUpdate

      protected abstract void onPreUpdate()
      An abstract function that allows derived classes to implement any desired behavior before the PDE solver applies its update function. The derived classes for 2D and 3D implement this to recompute the boundary values when Neumann conditions are used. If derived classes built on top of the 2D or 3D classes implement this also, they must call the base-class OnPreUpdate first.

    • onUpdate

      protected abstract void onUpdate()
      An abstract function for the update function of the PDE solver. The derived classes for 2D and 3D implement this to iterate over the image elements, updating an element only if it is not masked out.

    • onPostUpdate

      protected abstract void onPostUpdate()
      An abstract function that allows derived classes to implement any desired behavior after the PDE solver applies its update function. The derived classes for 2D and 3D implement this to swap the buffers for the next pass. If derived classes built on top of the 2D or 3D classes implement this also, they must call the base-class OnPostUpdate last.