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

Class LseFastMarch2

java.lang.Object

gov.nih.mipav.model.algorithms.levelset.LseFastMarch

gov.nih.mipav.model.algorithms.levelset.LseFastMarch2

public class LseFastMarch2
extends LseFastMarch

The fast-marching method for 2D images. This is based on material from J. Sethian's book, Level Set Methods and Fast Marching Methods.

Version:

0.1 November 7, 2006

Author:

David Eberly

Field Summary

Fields

Modifier and Type	Field	Description
protected int	m_iXBm1	XBm1 = XBound - 1
protected int	m_iXBound	The x-bound of the image, call it XBound.
protected int	m_iYBm1	YBm1 = YBound - 1
protected int	m_iYBound	The y-bound of the image, call it YBound.

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

m_afInvSpeed, m_afTime, m_akTrial, m_fMaxTime, m_fMinTime, m_iQuantity, m_kHeap

Constructor Summary

Constructors

Constructor	Description
LseFastMarch2(int iXBound, int iYBound, float[] afSpeed, int[] aiSeeds)	Create a new fast marching object for a 2D image.
LseFastMarch2(int iXBound, int iYBound, float fSpeed, int[] aiSeeds)	Create a new fast marching object for a 2D image.

Method Summary

Modifier and Type	Method	Description
protected void	computeTime(int i)	Compute the visitation time for an image element.
int[]	getBoundary()	Get the indices of the boundary points of the current region.
int	getXBound()	Get the x-bound for the image.
int	getYBound()	Get the y-bound for the image.
int	index(int iX, int iY)	Compute the 1-dimensional index for the pixel (x,y).
protected void	initialize(int iXBound, int iYBound)	Initialization of the 2D fast marching object.
boolean	isBoundary(int i)	An image element is a boundary point when it is on the boundary of the current region.
void	iterate()	Run one iteration of the fast marching algorithm.

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

computeTimeExtremes, getInterior, getMaxTime, getMinTime, getQuantity, getTime, initialize, initializeSpeed, initializeSpeed, isFar, isInterior, isTrial, isValid, isZeroSpeed, setTime

Methods inherited from class java.lang.Object

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

Field Detail

m_iXBound

protected int m_iXBound

The x-bound of the image, call it XBound.

m_iYBound

protected int m_iYBound

The y-bound of the image, call it YBound.

m_iXBm1

protected int m_iXBm1

XBm1 = XBound - 1

m_iYBm1

protected int m_iYBm1

YBm1 = YBound - 1

Constructor Detail

LseFastMarch2

public LseFastMarch2(int iXBound,
                     int iYBound,
                     float[] afSpeed,
                     int[] aiSeeds)

Create a new fast marching object for a 2D image.

Parameters:

iXBound - The x-bound of the image.

iYBound - The y-bound of the image.

afSpeed - The speeds of the image elements.

aiSeeds - The initial region points.

LseFastMarch2

public LseFastMarch2(int iXBound,
                     int iYBound,
                     float fSpeed,
                     int[] aiSeeds)

Create a new fast marching object for a 2D image.

Parameters:

iXBound - The x-bound of the image.

iYBound - The y-bound of the image.

fSpeed - The common speed of the image elements.

aiSeeds - The initial region points.

Method Detail

getXBound

public final int getXBound()

Get the x-bound for the image.

Returns:

The x-bound for the image.

getYBound

public final int getYBound()

Get the y-bound for the image.

Returns:

The y-bound for the image.

index

public final int index(int iX,
                       int iY)

Compute the 1-dimensional index for the pixel (x,y).

Parameters:

iX - The x-coordinate of the pixel.

iY - The y-coordinate of the pixel.

Returns:

The 1-dimensional index for the pixel.

getBoundary

public int[] getBoundary()

Get the indices of the boundary points of the current region.

Specified by:

getBoundary in class LseFastMarch

Returns:

The array of indices of the boundary points.

isBoundary

public boolean isBoundary(int i)

An image element is a boundary point when it is on the boundary of the current region.

Specified by:

isBoundary in class LseFastMarch

Parameters:

i - The index of the image element.

Returns:

The Boolean result indicating whether or not the image element is a boundary point.

iterate

public void iterate()

Run one iteration of the fast marching algorithm.

Specified by:

iterate in class LseFastMarch

initialize

protected void initialize(int iXBound,
                          int iYBound)

Initialization of the 2D fast marching 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.

computeTime

protected void computeTime(int i)

Compute the visitation time for an image element. In most cases, the time is a root to a quadratic equation that is derived from the finite-difference method used to propagate the region boundary using the inverse speeds.

Parameters:

i - The index of the image element.