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

Class LseCurvatureFlow2

java.lang.Object

gov.nih.mipav.model.algorithms.levelset.LsePdeFilter

gov.nih.mipav.model.algorithms.levelset.LsePdeFilter2

gov.nih.mipav.model.algorithms.levelset.LseCurvatureFlow2

public class LseCurvatureFlow2
extends LsePdeFilter2

This class implements the curvature flow filter for 2D images using a finite-difference-based solver for the partial differential equation:

du/dt = |grad(u)|*divergence(grad(u)/|grad(u)|)

where u(x,y,t) is the evolved image at time t, du/dt is the time derivative of u, and grad(u) is the gradient of u with respect to the spatial variables. The notation divergence(Q) = Q0_x + Q1_y, the sum of first-order derivatives of the vector-valued function Q = (Q0,Q1).

The right-hand side of the PDE is the product of the gradient magnitude with the curvature of the level curves.

Version:

0.1 November 7, 2006

Author:

David Eberly

Field Summary

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

Constructor	Description
LseCurvatureFlow2(int iXBound, int iYBound, float fXSpacing, float fYSpacing, float[] afData, boolean[] abMask, float fBorderValue, int eScaleType)	Creates a new LseCurvatureFlow2 object.

Method Summary

Modifier and Type	Method	Description
protected void	onUpdate(int iX, int iY)	The per-pixel update function of the PDE solver.

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, onPreUpdate, 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

Constructor Detail

LseCurvatureFlow2

public LseCurvatureFlow2(int iXBound,
                         int iYBound,
                         float fXSpacing,
                         float fYSpacing,
                         float[] afData,
                         boolean[] abMask,
                         float fBorderValue,
                         int eScaleType)

Creates a new LseCurvatureFlow2 object.

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

onUpdate

protected void onUpdate(int iX,
                        int iY)

The per-pixel update function of the PDE solver.

Specified by:

onUpdate in class LsePdeFilter2

Parameters:

iX - The x-value of the pixel to be updated.

iY - The y-value of the pixel to be updated.