java.lang.Object
- gov.nih.mipav.model.algorithms.levelset.LsePdeFilter
- - gov.nih.mipav.model.algorithms.levelset.LsePdeFilter2
  - - gov.nih.mipav.model.algorithms.levelset.LseEvolve2

Direct Known Subclasses:

LseGeodesicActiveContour2, LseShapeDetection2, LseThreshold2
```
public abstract class LseEvolve2
extends LsePdeFilter2
```
The abstract base class for level-set evolution of 2D images. It is based on PDEs that are solved numerically using finite-difference approximations.

Version:

0.1 November 7, 2006

Author:

David Eberly

Field Summary

Fields
Modifier and Type	Field	Description
`protected float[][]`	`m_aafD2`	The second-order derivatives of the current pixel.
`protected float[]`	`m_afAdvection`	The advection for the current pixel.
`protected float[]`	`m_afD1`	The first-order derivatives of the current pixel.
`protected float[]`	`m_afD1Bwd`	Backward finite-difference approximations to the first-order derivatives of the current pixel.
`protected float[]`	`m_afD1Fwd`	Forward finite-difference approximations to the first-order derivatives of the current pixel.
`protected float`	`m_fD0`	The image value of the current pixel.
`protected float`	`m_fGradMagSqr`	The squared magnitude of the gradient vector for the current pixel.
`protected LseParameters`	`m_kParameters`	The parameters associated with level-set evolution.

Fields inherited from class gov.nih.mipav.model.algorithms.levelset.LsePdeFilter2
m_aabMask, m_aafDst, m_aafSrc, m_fFourthInvDxDy, m_fHalfInvDx, m_fHalfInvDy, m_fInvDx, m_fInvDxDx, m_fInvDy, m_fInvDyDy, m_fUmm, m_fUmp, m_fUmz, m_fUpm, m_fUpp, m_fUpz, m_fUzm, m_fUzp, m_fUzz, m_fXSpacing, m_fYSpacing, m_iXBound, m_iYBound

Fields inherited from class gov.nih.mipav.model.algorithms.levelset.LsePdeFilter
m_eScaleType, m_fBorderValue, m_fMin, m_fOffset, m_fScale, m_fTimeStep, m_iQuantity, NONE, PRESERVE_ZERO, SYMMETRIC, UNIT

Constructor Summary

Constructors
Modifier	Constructor	Description
`protected`	`LseEvolve2(int iXBound, int iYBound, float fXSpacing, float fYSpacing, float[] afData, boolean[] abMask, float fBorderValue, int eScaleType)`	Create a new level-set evolver for 2D images.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected float[]`	`computeAdvection(int iX, int iY)`	Override this function to implement the desired advection for your level-set evolver.
`protected float`	`computeCurvature(int iX, int iY)`	Compute the product of length and curvature at the pixel (x,y).
`protected float`	`computeCurvatureSpeed(int iX, int iY)`	Override this function to implement the desired curvature speed for your level-set evolver.
`protected float`	`computeFunction(int iX, int iY)`	Evolution support.
`protected float`	`computeLaplacianSpeed(int iX, int iY)`	Override this function to implement the desired Laplacian speed for your level-set evolver.
`protected float`	`computePropagationSpeed(int iX, int iY)`	Override this function to implement the desired propagation speed for your level-set evolver.
`LseParameters`	`getParameters()`	Get the current level-set evolution parameters.
`protected void`	`onPreUpdate()`	The override of LsePdeFilter2.onPreUpdate.
`protected void`	`onUpdate(int iX, int iY)`	The override of LsePdeFilter2.onUpdate.

Methods inherited from class gov.nih.mipav.model.algorithms.levelset.LsePdeFilter2
assignDirichletImageBorder, assignDirichletMaskBorder, assignNeumannImageBorder, assignNeumannMaskBorder, getMask, getU, getUx, getUxx, getUxy, getUy, getUyy, getXBound, getXSpacing, getYBound, getYSpacing, lookUp5, lookUp9, onPostUpdate, onUpdate

Methods inherited from class gov.nih.mipav.model.algorithms.levelset.LsePdeFilter
getBorderValue, getQuantity, getScaleType, getTimeStep, setTimeStep, update

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - m_kParameters
```
protected LseParameters m_kParameters
```
    The parameters associated with level-set evolution.
  - m_fD0
```
protected float m_fD0
```
    The image value of the current pixel.
  - m_afD1
```
protected float[] m_afD1
```
    The first-order derivatives of the current pixel.
  - m_aafD2
```
protected float[][] m_aafD2
```
    The second-order derivatives of the current pixel.
  - m_afD1Fwd
```
protected float[] m_afD1Fwd
```
    Forward finite-difference approximations to the first-order derivatives of the current pixel.
  - m_afD1Bwd
```
protected float[] m_afD1Bwd
```
    Backward finite-difference approximations to the first-order derivatives of the current pixel.
  - m_fGradMagSqr
```
protected float m_fGradMagSqr
```
    The squared magnitude of the gradient vector for the current pixel.
  - m_afAdvection
```
protected float[] m_afAdvection
```
    The advection for the current pixel.
- Constructor Detail
  - LseEvolve2
```
protected LseEvolve2(int iXBound,
                     int iYBound,
                     float fXSpacing,
                     float fYSpacing,
                     float[] afData,
                     boolean[] abMask,
                     float fBorderValue,
                     int eScaleType)
```
    Create a new level-set evolver for 2D images.
    
    Parameters:
    
    iXBound - The x-bound of the image.
    
    iYBound - The y-bound of the image.
    
    fXSpacing - The x-spacing of the image.
    
    fYSpacing - The y-spacing of the image.
    
    afData - The image elements, stored in lexicographical order.
    
    abMask - The image mask, stored in lexicographical order. A pixel value is processed by the PDE solver only when the mask value is false.
    
    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 Detail
  - getParameters
```
public final LseParameters getParameters()
```
    Get the current level-set evolution parameters.
    
    Returns:
    
    The current level-set evolution parameters.
  - computeFunction
```
protected final float computeFunction(int iX,
                                      int iY)
```
    Evolution support. ComputeTimeStep() is called each time before ComputeFunction() is called. The function ComputeCurvature() actually computes k*L, where k is the curvature and L is the length of the gradient vector. The resulting quantity is
    
    k*L = (Uxx*Uy*Uy - 2*Uxy*Ux*Uy + Uyy*Ux*Ux)/(Ux*Ux + Uy*Uy)
    
    where Ux and Uy are first-order partial derivatives and Uxx, Uxy, and Uyy are second-order partial derivatives.
    
    Parameters:
    
    iX - The x-coordinate of the pixel.
    
    iY - The y-coordinate of the pixel.
    
    Returns:
    
    The value of the right-hand side of the PDE that governs the level-set evolution.
  - computeCurvature
```
protected final float computeCurvature(int iX,
                                       int iY)
```
    Compute the product of length and curvature at the pixel (x,y).
    
    Parameters:
    
    iX - The x-coordinate of the pixel.
    
    iY - The y-coordinate of the pixel.
    
    Returns:
    
    The product of length and curvature at the pixel.
  - computeAdvection
```
protected float[] computeAdvection(int iX,
                                   int iY)
```
    Override this function to implement the desired advection for your level-set evolver.
    
    Parameters:
    
    iX - The x-coordinate of the pixel.
    
    iY - The y-coordinate of the pixel.
    
    Returns:
    
    The advection at the pixel.
  - computePropagationSpeed
```
protected float computePropagationSpeed(int iX,
                                        int iY)
```
    Override this function to implement the desired propagation speed for your level-set evolver.
    
    Parameters:
    
    iX - The x-coordinate of the pixel.
    
    iY - The y-coordinate of the pixel.
    
    Returns:
    
    The propagation speed at the pixel.
  - computeCurvatureSpeed
```
protected float computeCurvatureSpeed(int iX,
                                      int iY)
```
    Override this function to implement the desired curvature speed for your level-set evolver.
    
    Parameters:
    
    iX - The x-coordinate of the pixel.
    
    iY - The y-coordinate of the pixel.
    
    Returns:
    
    The curvature speed at the pixel.
  - computeLaplacianSpeed
```
protected float computeLaplacianSpeed(int iX,
                                      int iY)
```
    Override this function to implement the desired Laplacian speed for your level-set evolver.
    
    Parameters:
    
    iX - The x-coordinate of the pixel.
    
    iY - The y-coordinate of the pixel.
    
    Returns:
    
    The Laplacian speed at the pixel.
  - onPreUpdate
```
protected void onPreUpdate()
```
    The override of LsePdeFilter2.onPreUpdate. This is where ComputeTimeStep is called.
    
    Overrides:
    
    onPreUpdate in class LsePdeFilter2
  - onUpdate
```
protected void onUpdate(int iX,
                        int iY)
```
    The override of LsePdeFilter2.onUpdate. This is where ComputeFunction is called.
    
    Specified by:
    
    onUpdate in class LsePdeFilter2
    
    Parameters:
    
    iX - The x-coordinate of the pixel.
    
    iY - The y-coordinate of the pixel.

Class LseEvolve2

Field Summary

Fields inherited from class gov.nih.mipav.model.algorithms.levelset.LsePdeFilter2

Fields inherited from class gov.nih.mipav.model.algorithms.levelset.LsePdeFilter

Constructor Summary

Method Summary

Methods inherited from class gov.nih.mipav.model.algorithms.levelset.LsePdeFilter2

Methods inherited from class gov.nih.mipav.model.algorithms.levelset.LsePdeFilter

Methods inherited from class java.lang.Object

Field Detail

m_kParameters

m_fD0

m_afD1

m_aafD2

m_afD1Fwd

m_afD1Bwd

m_fGradMagSqr

m_afAdvection

Constructor Detail

LseEvolve2

Method Detail

getParameters

computeFunction

computeCurvature

computeAdvection

computePropagationSpeed

computeCurvatureSpeed

computeLaplacianSpeed

onPreUpdate

onUpdate