Fast Marching algorithm for surface front propagation. More...

#include <FastMarchingForPropagation.h>

Inheritance diagram for CCCoreLib::FastMarchingForPropagation:

Collaboration diagram for CCCoreLib::FastMarchingForPropagation:

[legend]

Classes
class	PropagationCell
	A Fast Marching grid cell for surfacical propagation. More...

Public Member Functions
	FastMarchingForPropagation ()
	Default constructor.

int	init (GenericCloud theCloud, DgmOctree theOctree, unsigned char gridLevel, bool constantAcceleration=false)
	Initializes the grid with a point cloud (and ist corresponding octree) More...

bool	extractPropagatedPoints (ReferenceCloud *Zk)
	Returns a list of the points (references to) reached by the propagation process. More...

bool	setPropagationTimingsAsDistances ()
	Sets the propagation timings as distances for each point. More...

void	setDetectionThreshold (float value)
	Sets the threshold for propagation stop. More...

void	setJumpCoef (float value)
	Sets the accceleration exageration factor. More...

void	findPeaks ()
	Find peaks of local acceleration values. More...

int	propagate () override
	Propagates the front. More...

Public Member Functions inherited from CCCoreLib::FastMarching
	FastMarching ()
	Default constructor.

virtual	~FastMarching ()
	Destructor.

virtual bool	setSeedCell (const Tuple3i &pos)
	Sets a given cell as "seed". More...

virtual int	propagate ()=0
	Propagates the front. More...

virtual void	cleanLastPropagation ()

virtual float	getTime (Tuple3i &pos, bool absoluteCoordinates=false) const
	Returns the front arrival time at a given cell. More...

virtual void	setExtendedConnectivity (bool state)
	Sets extended connectivity mode. More...

Protected Member Functions
float	computeTCoefApprox (Cell currentCell, Cell neighbourCell) const override
	Computes the front acceleration between two cells. More...

int	step () override
	Propagates the front (one step) More...

bool	instantiateGrid (unsigned size) override
	Instantiates grid in memory. More...

Protected Member Functions inherited from CCCoreLib::FastMarching
unsigned	pos2index (const Tuple3i &pos) const

virtual int	initGridWithOctree (DgmOctree *octree, unsigned char gridLevel)
	Intializes the grid as a snapshot of an octree structure at a given subdivision level. More...

virtual int	initGrid (float step, unsigned dim[3])
	Intializes the grid with a given step and dimensions. More...

virtual int	initOther ()
	Intializes other dimension-related variables and finishes the initialization job.

virtual float	computeT (unsigned index)
	Computes the front arrival time at a given cell. More...

virtual float	computeTCoefApprox (Cell currentCell, Cell neighbourCell) const =0
	Computes the front acceleration between two cells. More...

virtual int	step ()=0
	Propagates the front (one step) More...

virtual void	initTrialCells ()
	Initializes the TRIAL cells list. More...

virtual bool	instantiateGrid (unsigned size)=0
	Instantiates grid in memory. More...

template<class T >
bool	instantiateGridTpl (unsigned size)
	Grid instantiation helper.

virtual void	addTrialCell (unsigned index)
	Add a cell to the TRIAL cells list. More...

virtual void	addActiveCell (unsigned index)
	Add a cell to the ACTIVE cells list. More...

virtual void	addIgnoredCell (unsigned index)
	Add a cell to the IGNORED cells list. More...

virtual unsigned	getNearestTrialCell ()
	Returns the TRIAL cell with the smallest front arrival time. More...

void	resetCells (std::vector< unsigned > &list)
	Resets the state of cells in a given list. More...

Protected Attributes
float	m_jumpCoef
	Accceleration exageration factor.

float	m_detectionThreshold
	Threshold for propagation stop.

Protected Attributes inherited from CCCoreLib::FastMarching
std::vector< unsigned >	m_activeCells
	ACTIVE cells list.

std::vector< unsigned >	m_trialCells
	TRIAL cells list.

std::vector< unsigned >	m_ignoredCells
	IGNORED cells lits.

bool	m_initialized
	Specifiies whether structure is initialized or not.

unsigned	m_dx
	Grid size along the X dimension.

unsigned	m_dy
	Grid size along the Y dimension.

unsigned	m_dz
	Grid size along the Z dimension.

unsigned	m_rowSize
	Shift for cell access acceleration (Y dimension)

unsigned	m_sliceSize
	Shift for cell access acceleration (Z dimension)

unsigned	m_indexShift
	First index of innerbound grid.

unsigned	m_gridSize
	Grid size.

Cell **	m_theGrid
	Grid used to process Fast Marching.

DgmOctree *	m_octree
	Associated octree.

unsigned char	m_gridLevel
	Equivalent octree subdivision level.

float	m_cellSize
	Octree cell size at equivalent subdivision level.

Tuple3i	m_minFillIndexes
	Octree min fill indexes at 'm_gridLevel'.

unsigned	m_numberOfNeighbours
	Current number of neighbours (6 or 26)

int	m_neighboursIndexShift [CC_FM_MAX_NUMBER_OF_NEIGHBOURS]
	Neighbours coordinates shifts in grid.

float	m_neighboursDistance [CC_FM_MAX_NUMBER_OF_NEIGHBOURS]
	Neighbours distance weight.

Detailed Description

Fast Marching algorithm for surface front propagation.

Extends the FastMarching class.

Member Function Documentation

◆ computeTCoefApprox()

float FastMarchingForPropagation::computeTCoefApprox	(	Cell *	currentCell,
		Cell *	neighbourCell
	)		const

overrideprotectedvirtual

Computes the front acceleration between two cells.

Parameters

currentCell	the "central" cell
neighbourCell	the other cell

Returns: the front acceleration

Implements CCCoreLib::FastMarching.

◆ extractPropagatedPoints()

bool FastMarchingForPropagation::extractPropagatedPoints ( ReferenceCloud * Zk )

Returns a list of the points (references to) reached by the propagation process.

Returns a cloud of points (references to) corresponding to the points that are lying in cells that have been visited by the last propagation process.

Parameters

[out] Zk (reference) point cloud

◆ findPeaks()

void FastMarchingForPropagation::findPeaks ( )

Find peaks of local acceleration values.

This method is useful when using this Fast Marching algorithm in a Watershed process. Peak cells are automatically set as "seeds".

◆ init()

int FastMarchingForPropagation::init	(	GenericCloud *	theCloud,
		DgmOctree *	theOctree,
		unsigned char	gridLevel,
		bool	constantAcceleration = `false`
	)

Initializes the grid with a point cloud (and ist corresponding octree)

The points should be associated to scalar values. Warning: be sure to activate an OUTPUT scalar field on the input cloud The Fast Marching grid will have the same characteristics as the octree considered at a given level of subdivision. The local front acceleration in each cell is deduced from the scalar values associated to the points lying in the octree cell (mean value).

Parameters

theCloud	the point cloud
theOctree	the associated octree
gridLevel	the level of subdivision
constantAcceleration	specifies if the acceleration is constant or shoul be computed from the cell points scalar values

Returns: a negative value if something went wrong

◆ instantiateGrid()

bool CCCoreLib::FastMarchingForPropagation::instantiateGrid ( unsigned size )

inlineoverrideprotectedvirtual

Instantiates grid in memory.

Grid is also filled with zeros.

Parameters

size grid size

Returns: success

Implements CCCoreLib::FastMarching.

◆ propagate()

int FastMarchingForPropagation::propagate ( )

overridevirtual

Propagates the front.

The seeds should have already been initialized

Returns: propagation result (errors = negative values)

Implements CCCoreLib::FastMarching.

◆ setDetectionThreshold()

void CCCoreLib::FastMarchingForPropagation::setDetectionThreshold ( float value )

inline

Sets the threshold for propagation stop.

This threshold corresponds to the maximum front arrival time increase allowed. If the delta between the fornt arrival time at two consecutive cells is higher, the propagation process is stoped.

Parameters

value the threshold

◆ setJumpCoef()

void CCCoreLib::FastMarchingForPropagation::setJumpCoef ( float value )

inline

Sets the accceleration exageration factor.

In order to detect the front arrival time jumps (see FastMarchingForPropagation::setDetectionThreshold), it is possible to exaggerate the result of the acceleration computation with this factor.

Parameters

value the acceleration exageration factor

◆ setPropagationTimingsAsDistances()

bool FastMarchingForPropagation::setPropagationTimingsAsDistances ( )

Sets the propagation timings as distances for each point.

Returns: true if ok, false otherwise

◆ step()

int FastMarchingForPropagation::step ( )

overrideprotectedvirtual

Propagates the front (one step)

Returns: a negative value if a problem occurred

Implements CCCoreLib::FastMarching.

The documentation for this class was generated from the following files:

FastMarchingForPropagation.h
FastMarchingForPropagation.cpp

Classes

Public Member Functions

Protected Member Functions

Protected Attributes

Detailed Description

Member Function Documentation

◆ computeTCoefApprox()

◆ extractPropagatedPoints()

◆ findPeaks()

◆ init()

◆ instantiateGrid()

◆ propagate()

◆ setDetectionThreshold()

◆ setJumpCoef()

◆ setPropagationTimingsAsDistances()

◆ step()