sdet_contour Class Reference

#include <sdet_contour.h>

Detailed Description

Definition at line 81 of file sdet_contour.h.

Public Member Functions

sdet_contour (float min_strength, int min_length, float min_jump, float max_gap=2.236068f)

Save parameters and create workspace for detecting contours.

~sdet_contour ()

Free space allocated for detecting contours.

bool FindNetwork (gevd_bufferxy &edgels, bool junctionp, const int njunction, const int *junctionx, const int *junctiony, vcl_vector< vtol_edge_2d_sptr > *&edges, vcl_vector< vtol_vertex_2d_sptr > *&vertices)

Trace the edgel locations to form a topological network (edges, vertices).

void SubPixelAccuracy (vcl_vector< vtol_edge_2d_sptr > &edges, vcl_vector< vtol_vertex_2d_sptr > &vertices, const gevd_bufferxy &locationx, const gevd_bufferxy &locationy)

Use interpolation of the gradient to localize to sub-pixel accuracy.

void InsertBorder (vcl_vector< vtol_edge_2d_sptr > &edges, vcl_vector< vtol_vertex_2d_sptr > &vertices)

Insert a border at the ROI boundary to support connected components.

void BeSilent ()

void BeTalkative ()

void SetDebug ()

void ClearDebug ()

Static Public Member Functions

static void EqualizeSpacing (vcl_vector< vtol_edge_2d_sptr > &chains)

apply a smoothing filter to edgel_chain(s).

static void Translate (vcl_vector< vtol_edge_2d_sptr > &edges, vcl_vector< vtol_vertex_2d_sptr > &vertices, float tx=0.5, float ty=0.5)

computation is carried out in a zero origin ROI - translate back.

static void ClearNetwork (vcl_vector< vtol_edge_2d_sptr > *&edges, vcl_vector< vtol_vertex_2d_sptr > *&vertices)

clear network storage (edges and vertices).

static void SetEdgelData (gevd_bufferxy &grad_mag, gevd_bufferxy &angle, vcl_vector< vtol_edge_2d_sptr > &edges)

Set edgel gradient and direction values from pixel arrays.

Static Public Attributes

static bool talkative_ = false

static bool debug_ = false

Protected Member Functions

int FindChains (gevd_bufferxy &edgels, const int njunction, const int *junctionx, const int *junctiony, vcl_vector< vtol_edge_2d_sptr > &edges)

link detected edgels and junctions into chains.

int FindJunctions (gevd_bufferxy &edgels, vcl_vector< vtol_edge_2d_sptr > &edges, vcl_vector< vtol_vertex_2d_sptr > &vertices)

Establish vertices; improve connectivity by jumping small gaps.

bool move_junction (vtol_vertex_2d_sptr const &junction, int &index, vdgl_digital_curve_sptr const &dc)

Move a junction to lie on the intersecting digital curve.

void update_edgel_chain (vtol_edge_2d_sptr const &edge, const int old_x, const int old_y, vtol_vertex_2d_sptr &v)

when a vertex position is moved, an edge's edgel chain must potentially be replaced.

bool near_border (vtol_vertex_2d_sptr const &v)

Determine if a vertex is in the border strip.

bool DetectJunction (vtol_vertex_2d_sptr const &end, int &index, vtol_edge_2d_sptr &weaker, vtol_edge_2d_sptr &stronger, const int maxSpiral, const gevd_bufferxy &edgels)

Detect a nearby vertex by carrying out a spiral search.

void BreakChain (vtol_vertex_2d_sptr const &junction, int &index, vtol_edge_2d_sptr const &stronger, vtol_edge_2d_sptr &longer, vtol_edge_2d_sptr &shorter)

Break a chain at a junction and form a "T".

void LoopChain (vtol_vertex_2d_sptr const &junction, int &index, vtol_edge_2d_sptr const &chain, vtol_edge_2d_sptr &straight, vtol_edge_2d_sptr &curled)

Break a single edge at junction and form a loop.

void BreakCycle (vtol_vertex_2d_sptr const &junction, int &index, vtol_edge_2d_sptr const &stronger, vtol_edge_2d_sptr &split)

Break a closed cycle and insert a vertex at junction.

vtol_vertex_2d_sptr DetectTouch (vtol_vertex_2d_sptr const &end, const int maxSpiral)

Detect nearby vertices by searching in a spiral pattern.

void MergeEndPtTouchingEndPt (vtol_vertex_2d_sptr const &end1, vtol_vertex_2d_sptr const &end2, vtol_edge_2d_sptr &merge, vtol_edge_2d_sptr &longer, vtol_edge_2d_sptr &shorter)

Connect an isolated endpoint to a nearby single vertex on a different edge.

bool MergeEndPtTouchingJunction (vtol_vertex_2d_sptr const &endpt, vtol_vertex_2d_sptr const &junction, vtol_edge_2d_sptr &old_edge, vtol_edge_2d_sptr &new_edge)

Connect an isolated endpoint to a nearby junction (2 or more edges).

bool MergeEndPtsOfChain (vtol_vertex_2d_sptr const &endpt, vtol_vertex_2d_sptr const &other, vtol_vertex_2d_sptr &removed_vert)

Connect an isolated endpoint to the other vertex on the same edge.

Static Protected Member Functions

static void LookupTableInsert (vcl_vector< vtol_edge_2d_sptr > &set, vtol_edge_2d_sptr elmt)

insert an edge into a table indexed by vsol id.

static void LookupTableReplace (vcl_vector< vtol_edge_2d_sptr > &set, vtol_edge_2d_sptr deleted, vtol_edge_2d_sptr inserted)

replace an edge in a table indexed by vsol id.

static void LookupTableRemove (vcl_vector< vtol_edge_2d_sptr > &set, vtol_edge_2d_sptr elmt)

remove an edge from a table indexed by vsol id.

static void LookupTableCompress (vcl_vector< vtol_edge_2d_sptr > &set)

eliminate gaps in the table by removing empty entries.

static void LookupTableInsert (vcl_vector< vtol_vertex_2d_sptr > &set, vtol_vertex_2d_sptr elmt)

insert a vertex into a table indexed by vsol id.

static void LookupTableReplace (vcl_vector< vtol_vertex_2d_sptr > &set, vtol_vertex_2d_sptr deleted, vtol_vertex_2d_sptr inserted)

replace a vertex in a table indexed by vsol id.

static void LookupTableRemove (vcl_vector< vtol_vertex_2d_sptr > &set, vtol_vertex_2d_sptr elmt)

remove a vertex from a table indexed by vsol id.

static void LookupTableCompress (vcl_vector< vtol_vertex_2d_sptr > &set)

eliminate gaps in the table by removing empty entries.

Protected Attributes

float minStrength

class members.

int minLength

float minJump

float max_gap

int maxSpiral

vbl_array_2d< vtol_edge_2d_sptr > * edgeMap

vbl_array_2d< vtol_vertex_2d_sptr > * vertexMap

vcl_vector< vtol_vertex_2d_sptr > test_verts_

Constructor & Destructor Documentation

sdet_contour::sdet_contour ( float min_strength,

int min_length,

float min_jump,

float max_gap_in = 2.236068f

)

Save parameters and create workspace for detecting contours.
Each contour must have at least 1 pixel above min_strength, and its number of internal pixels must be above min_length. This is a heuristic hysteresis scheme that prunes weak or short isolated chains. To join a weaker contour to a stronger contour, a junction must have a change in response above min_jump on the stronger contour. This way, only strong junctions are detected.
Definition at line 113 of file sdet_contour.cxx.

sdet_contour::~sdet_contour ( )

Free space allocated for detecting contours.

Definition at line 163 of file sdet_contour.cxx.

Member Function Documentation

void sdet_contour::BeSilent ( ) [inline]

Definition at line 124 of file sdet_contour.h.

void sdet_contour::BeTalkative ( ) [inline]

Definition at line 125 of file sdet_contour.h.

void sdet_contour::BreakChain ( vtol_vertex_2d_sptr const & junction,

int & index,

vtol_edge_2d_sptr const & stronger,

vtol_edge_2d_sptr & longer,

vtol_edge_2d_sptr & shorter

) [protected]

Break a chain at a junction and form a "T".
junction 0---------------o----------------------0 index nedgels-1 edge1 edge2
Definition at line 1017 of file sdet_contour.cxx.

void sdet_contour::BreakCycle ( vtol_vertex_2d_sptr const & junction,

int & index,

vtol_edge_2d_sptr const & stronger,

vtol_edge_2d_sptr & split

) [protected]

Break a closed cycle and insert a vertex at junction.
stronger (no vertex initially) ------------ | | | | 0-------0 junction | | | | | ------------ split - the new edge
Definition at line 865 of file sdet_contour.cxx.

void sdet_contour::ClearDebug ( ) [inline]

Definition at line 127 of file sdet_contour.h.

void sdet_contour::ClearNetwork ( vcl_vector< vtol_edge_2d_sptr > *& edges,

vcl_vector< vtol_vertex_2d_sptr > *& vertices

) [static]

clear network storage (edges and vertices).
Remove all digital chains of edges. Edges and vertices are removed with UnProtect().
Definition at line 2525 of file sdet_contour.cxx.

bool sdet_contour::DetectJunction ( vtol_vertex_2d_sptr const & endv,

int & index,

vtol_edge_2d_sptr & weaker,

vtol_edge_2d_sptr & stronger,

const int maxSpiral,

const gevd_bufferxy & edgels

) [protected]

Detect a nearby vertex by carrying out a spiral search.
The outputs are: index, weaker and stronger. endv is a vertex corresponding to a dangling end of an edge. i.) If the end vertex is bounding more than one edge, the routine returns false. ii.) Otherwise a spiral search is carried out around the end with a radius given by maxSpiral. Some of the nearby points on the edge connected to endv, are erased so that they are not found in the search. iii.) The edgel with maximum strength is found. If there is none, the routine returns false. iv.) The edge containing the found edgel is called "stronger" and the the location on that edge where the edgel was found is "index"
Definition at line 585 of file sdet_contour.cxx.

vtol_vertex_2d_sptr sdet_contour::DetectTouch ( vtol_vertex_2d_sptr const & endv,

const int maxSpiral

) [protected]

Detect nearby vertices by searching in a spiral pattern.
Find the neighboring vertex with the largest number of incident edges.
Definition at line 1300 of file sdet_contour.cxx.

void sdet_contour::EqualizeSpacing ( vcl_vector< vtol_edge_2d_sptr > & chains ) [static]

apply a smoothing filter to edgel_chain(s).
This will reduce square grid tessellation artifacts, and lead to more accurate estimation of the tangent direction, and local curvature angle, from finite differences in location. It is also useful to avoid weight artifacts in curve fitting caused by the periodic clustering of pixels along the chain. Truncating the float locations with int() will no longer map to the original pixels of the discrete chains.
Definition at line 2435 of file sdet_contour.cxx.

int sdet_contour::FindChains ( gevd_bufferxy & edgels,

const int njunction,

const int * junctionx,

const int * junctiony,

vcl_vector< vtol_edge_2d_sptr > & edges

) [protected]

link detected edgels and junctions into chains.
Thinning is not used, and so will avoid errors because of square grid tessellation. A chain can not cross itself. It can only touch itself or another chain, in which case a junction will be found later. The pixels of a chain include the 2 end points. End points and junctions are created in sdet_contour::FindJunctions. Return the number of chains found. Protected.
Definition at line 369 of file sdet_contour.cxx.

int sdet_contour::FindJunctions ( gevd_bufferxy & edgels,

vcl_vector< vtol_edge_2d_sptr > & edges,

vcl_vector< vtol_vertex_2d_sptr > & vertices

) [protected]

Establish vertices; improve connectivity by jumping small gaps.
Localize these junctions on the stronger contour to pixel accuracy, and break stronger chain into subchains. Also merge end points touching another end point or junction. Return the number of end points and junctions bounding all chains/cycles detected in sdet_contour::FindChains. Deletion/insertion to the network must be done completely, so that the connectivity links are updated. Protected.
Definition at line 1737 of file sdet_contour.cxx.

bool sdet_contour::FindNetwork ( gevd_bufferxy & edgels,

bool junctionp,

const int njunction,

const int * junctionx,

const int * junctiony,

vcl_vector< vtol_edge_2d_sptr > *& edges,

vcl_vector< vtol_vertex_2d_sptr > *& vertices

)

Trace the edgel locations to form a topological network (edges, vertices).
The contours must be less than 2 pixel wide, for example found from non maximum suppression. Isolated edgels and short segments are erased.
Definition at line 175 of file sdet_contour.cxx.

void sdet_contour::InsertBorder ( vcl_vector< vtol_edge_2d_sptr > & edges,

vcl_vector< vtol_vertex_2d_sptr > & vertices

)

Insert a border at the ROI boundary to support connected components.
The location of the border is at 3 pixels away from the real image border, because of kernel radius in convolution and non maximum suppression. Virtual border of image should be inserted after sdet_contour::FindChains() and sdet_contour::FindJunctions().
JLM - February 1999 Modified this routine extensively to move the border to the actual image ROI bounds. Chain endpoints are extended to intersect with the border. These changes were made to support region segmentation from edgels.
Definition at line 2095 of file sdet_contour.cxx.

void sdet_contour::LookupTableCompress ( vcl_vector< vtol_vertex_2d_sptr > & set ) [static, protected]

eliminate gaps in the table by removing empty entries.

Definition at line 2671 of file sdet_contour.cxx.

void sdet_contour::LookupTableCompress ( vcl_vector< vtol_edge_2d_sptr > & set ) [static, protected]

eliminate gaps in the table by removing empty entries.

Definition at line 2651 of file sdet_contour.cxx.

void sdet_contour::LookupTableInsert ( vcl_vector< vtol_vertex_2d_sptr > & set,

vtol_vertex_2d_sptr elmt

) [static, protected]

insert a vertex into a table indexed by vsol id.

Definition at line 2597 of file sdet_contour.cxx.

void sdet_contour::LookupTableInsert ( vcl_vector< vtol_edge_2d_sptr > & set,

vtol_edge_2d_sptr elmt

) [static, protected]

insert an edge into a table indexed by vsol id.
Protect it in the network.
Definition at line 2587 of file sdet_contour.cxx.

void sdet_contour::LookupTableRemove ( vcl_vector< vtol_vertex_2d_sptr > & set,

vtol_vertex_2d_sptr elmt

) [static, protected]

remove a vertex from a table indexed by vsol id.

Definition at line 2642 of file sdet_contour.cxx.

void sdet_contour::LookupTableRemove ( vcl_vector< vtol_edge_2d_sptr > & set,

vtol_edge_2d_sptr elmt

) [static, protected]

remove an edge from a table indexed by vsol id.
Also remove object from the network.
Definition at line 2632 of file sdet_contour.cxx.

void sdet_contour::LookupTableReplace ( vcl_vector< vtol_vertex_2d_sptr > & set,

vtol_vertex_2d_sptr deleted,

vtol_vertex_2d_sptr inserted

) [static, protected]

replace a vertex in a table indexed by vsol id.

Definition at line 2620 of file sdet_contour.cxx.

void sdet_contour::LookupTableReplace ( vcl_vector< vtol_edge_2d_sptr > & set,

vtol_edge_2d_sptr deleted,

vtol_edge_2d_sptr inserted

) [static, protected]

replace an edge in a table indexed by vsol id.
Also remove object from the network.
Definition at line 2608 of file sdet_contour.cxx.

void sdet_contour::LoopChain ( vtol_vertex_2d_sptr const & junction,

int & index,

vtol_edge_2d_sptr const & chain,

vtol_edge_2d_sptr & straight,

vtol_edge_2d_sptr & curled

) [protected]

Break a single edge at junction and form a loop.
This case occurs when the junction is caused by a chain touching itself
straight junction 0-------------------0-------- | | curled | | ---------
Definition at line 1122 of file sdet_contour.cxx.

bool sdet_contour::MergeEndPtsOfChain ( vtol_vertex_2d_sptr const & endpt,

vtol_vertex_2d_sptr const & other,

vtol_vertex_2d_sptr & removed_vert

) [protected]

Connect an isolated endpoint to the other vertex on the same edge.
endpt o------------------ o---- | other \ | ------------
The removed vertex is the either endpt or other, depending on the direction of the edge
Definition at line 1356 of file sdet_contour.cxx.

void sdet_contour::MergeEndPtTouchingEndPt ( vtol_vertex_2d_sptr const & end1,

vtol_vertex_2d_sptr const & end2,

vtol_edge_2d_sptr & merge,

vtol_edge_2d_sptr & longer,

vtol_edge_2d_sptr & shorter

) [protected]

Connect an isolated endpoint to a nearby single vertex on a different edge.
shorter gap longer 0-------------o o----------------------0 end1 end2
Definition at line 1430 of file sdet_contour.cxx.

bool sdet_contour::MergeEndPtTouchingJunction ( vtol_vertex_2d_sptr const & endpt,

vtol_vertex_2d_sptr const & junction,

vtol_edge_2d_sptr & old_edge,

vtol_edge_2d_sptr & new_edge

) [protected]

Connect an isolated endpoint to a nearby junction (2 or more edges).
------------ | | endpt | | O 0-----------o 0 junction 0 | | | ----------------------
Definition at line 1600 of file sdet_contour.cxx.

bool sdet_contour::move_junction ( vtol_vertex_2d_sptr const & junction,

int & index,

vdgl_digital_curve_sptr const & dc

) [protected]

Move a junction to lie on the intersecting digital curve.
Refine the intersection position to double precision
Definition at line 695 of file sdet_contour.cxx.

bool sdet_contour::near_border ( vtol_vertex_2d_sptr const & v ) [protected]

Determine if a vertex is in the border strip.
The strip supports the edge detection kernel
Definition at line 1282 of file sdet_contour.cxx.

void sdet_contour::SetDebug ( ) [inline]

Definition at line 126 of file sdet_contour.h.

void sdet_contour::SetEdgelData ( gevd_bufferxy & grad_mag,

gevd_bufferxy & angle,

vcl_vector< vtol_edge_2d_sptr > & edges

) [static]

Set edgel gradient and direction values from pixel arrays.
Rothwell's EdgeDetector. That is theta = (180/M_PI)*atan2(dI/dy, dI/dx)
Definition at line 2539 of file sdet_contour.cxx.

void sdet_contour::SubPixelAccuracy ( vcl_vector< vtol_edge_2d_sptr > & edges,

vcl_vector< vtol_vertex_2d_sptr > & vertices,

const gevd_bufferxy & locationx,

const gevd_bufferxy & locationy

)

Use interpolation of the gradient to localize to sub-pixel accuracy.
Truncating float locations with int(xy) should map to the original pixel locations. No interpolation is done at junctions of 3 or more contours, so a junction can have location error up to 1-2 pixel, tangential to the strong contour.
Definition at line 2019 of file sdet_contour.cxx.

void sdet_contour::Translate ( vcl_vector< vtol_edge_2d_sptr > & edges,

vcl_vector< vtol_vertex_2d_sptr > & vertices,

float tx = 0.5,

float ty = 0.5

) [static]

computation is carried out in a zero origin ROI - translate back.
If the image is extracted from an ROI, a translation of (roi->GetOrigX(), roi->GetOrigY()) must be done to have coordinates in the reference frame of the original image. Add 0.5 if you want to display location at center of pixel instead of upper-left corner.
Definition at line 2483 of file sdet_contour.cxx.

void sdet_contour::update_edgel_chain ( vtol_edge_2d_sptr const & edge,

const int old_x,

const int old_y,

vtol_vertex_2d_sptr & v

) [protected]

when a vertex position is moved, an edge's edgel chain must potentially be replaced.
old_x and old_y is the original end position. It is possible that the vertex can move up to 4 pixels. The new position is the location of v. Edgels are added from the end of the old digital_curve to the new vertex position.
Definition at line 723 of file sdet_contour.cxx.

Member Data Documentation

bool sdet_contour::debug_ = false [static]

Definition at line 130 of file sdet_contour.h.

vbl_array_2d<vtol_edge_2d_sptr>* sdet_contour::edgeMap [protected]

Definition at line 243 of file sdet_contour.h.

float sdet_contour::max_gap [protected]

Definition at line 241 of file sdet_contour.h.

int sdet_contour::maxSpiral [protected]

Definition at line 242 of file sdet_contour.h.

float sdet_contour::minJump [protected]

Definition at line 240 of file sdet_contour.h.

int sdet_contour::minLength [protected]

Definition at line 239 of file sdet_contour.h.

float sdet_contour::minStrength [protected]

class members.

Definition at line 238 of file sdet_contour.h.

bool sdet_contour::talkative_ = false [static]

Definition at line 129 of file sdet_contour.h.

vcl_vector<vtol_vertex_2d_sptr> sdet_contour::test_verts_ [protected]

Definition at line 245 of file sdet_contour.h.

vbl_array_2d<vtol_vertex_2d_sptr>* sdet_contour::vertexMap [protected]

Definition at line 244 of file sdet_contour.h.

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

contrib/brl/bseg/sdet/sdet_contour.h
contrib/brl/bseg/sdet/sdet_contour.cxx

Generated on Thu Jan 10 14:52:45 2008 for contrib/brl/bseg/sdet by

1.4.4


Public Member Functions
	sdet_contour (float min_strength, int min_length, float min_jump, float max_gap=2.236068f)
	Save parameters and create workspace for detecting contours.
	~sdet_contour ()
	Free space allocated for detecting contours.
bool	FindNetwork (gevd_bufferxy &edgels, bool junctionp, const int njunction, const int junctionx, const int junctiony, vcl_vector< vtol_edge_2d_sptr > &edges, vcl_vector< vtol_vertex_2d_sptr > &vertices)
	Trace the edgel locations to form a topological network (edges, vertices).
void	SubPixelAccuracy (vcl_vector< vtol_edge_2d_sptr > &edges, vcl_vector< vtol_vertex_2d_sptr > &vertices, const gevd_bufferxy &locationx, const gevd_bufferxy &locationy)
	Use interpolation of the gradient to localize to sub-pixel accuracy.
void	InsertBorder (vcl_vector< vtol_edge_2d_sptr > &edges, vcl_vector< vtol_vertex_2d_sptr > &vertices)
	Insert a border at the ROI boundary to support connected components.
void	BeSilent ()
void	BeTalkative ()
void	SetDebug ()
void	ClearDebug ()
Static Public Member Functions
static void	EqualizeSpacing (vcl_vector< vtol_edge_2d_sptr > &chains)
	apply a smoothing filter to edgel_chain(s).
static void	Translate (vcl_vector< vtol_edge_2d_sptr > &edges, vcl_vector< vtol_vertex_2d_sptr > &vertices, float tx=0.5, float ty=0.5)
	computation is carried out in a zero origin ROI - translate back.
static void	ClearNetwork (vcl_vector< vtol_edge_2d_sptr > &edges, vcl_vector< vtol_vertex_2d_sptr > &vertices)
	clear network storage (edges and vertices).
static void	SetEdgelData (gevd_bufferxy &grad_mag, gevd_bufferxy &angle, vcl_vector< vtol_edge_2d_sptr > &edges)
	Set edgel gradient and direction values from pixel arrays.
Static Public Attributes
static bool	talkative_ = false
static bool	debug_ = false
Protected Member Functions
int	FindChains (gevd_bufferxy &edgels, const int njunction, const int junctionx, const int junctiony, vcl_vector< vtol_edge_2d_sptr > &edges)
	link detected edgels and junctions into chains.
int	FindJunctions (gevd_bufferxy &edgels, vcl_vector< vtol_edge_2d_sptr > &edges, vcl_vector< vtol_vertex_2d_sptr > &vertices)
	Establish vertices; improve connectivity by jumping small gaps.
bool	move_junction (vtol_vertex_2d_sptr const &junction, int &index, vdgl_digital_curve_sptr const &dc)
	Move a junction to lie on the intersecting digital curve.
void	update_edgel_chain (vtol_edge_2d_sptr const &edge, const int old_x, const int old_y, vtol_vertex_2d_sptr &v)
	when a vertex position is moved, an edge's edgel chain must potentially be replaced.
bool	near_border (vtol_vertex_2d_sptr const &v)
	Determine if a vertex is in the border strip.
bool	DetectJunction (vtol_vertex_2d_sptr const &end, int &index, vtol_edge_2d_sptr &weaker, vtol_edge_2d_sptr &stronger, const int maxSpiral, const gevd_bufferxy &edgels)
	Detect a nearby vertex by carrying out a spiral search.
void	BreakChain (vtol_vertex_2d_sptr const &junction, int &index, vtol_edge_2d_sptr const &stronger, vtol_edge_2d_sptr &longer, vtol_edge_2d_sptr &shorter)
	Break a chain at a junction and form a "T".
void	LoopChain (vtol_vertex_2d_sptr const &junction, int &index, vtol_edge_2d_sptr const &chain, vtol_edge_2d_sptr &straight, vtol_edge_2d_sptr &curled)
	Break a single edge at junction and form a loop.
void	BreakCycle (vtol_vertex_2d_sptr const &junction, int &index, vtol_edge_2d_sptr const &stronger, vtol_edge_2d_sptr &split)
	Break a closed cycle and insert a vertex at junction.
vtol_vertex_2d_sptr	DetectTouch (vtol_vertex_2d_sptr const &end, const int maxSpiral)
	Detect nearby vertices by searching in a spiral pattern.
void	MergeEndPtTouchingEndPt (vtol_vertex_2d_sptr const &end1, vtol_vertex_2d_sptr const &end2, vtol_edge_2d_sptr &merge, vtol_edge_2d_sptr &longer, vtol_edge_2d_sptr &shorter)
	Connect an isolated endpoint to a nearby single vertex on a different edge.
bool	MergeEndPtTouchingJunction (vtol_vertex_2d_sptr const &endpt, vtol_vertex_2d_sptr const &junction, vtol_edge_2d_sptr &old_edge, vtol_edge_2d_sptr &new_edge)
	Connect an isolated endpoint to a nearby junction (2 or more edges).
bool	MergeEndPtsOfChain (vtol_vertex_2d_sptr const &endpt, vtol_vertex_2d_sptr const &other, vtol_vertex_2d_sptr &removed_vert)
	Connect an isolated endpoint to the other vertex on the same edge.
Static Protected Member Functions
static void	LookupTableInsert (vcl_vector< vtol_edge_2d_sptr > &set, vtol_edge_2d_sptr elmt)
	insert an edge into a table indexed by vsol id.
static void	LookupTableReplace (vcl_vector< vtol_edge_2d_sptr > &set, vtol_edge_2d_sptr deleted, vtol_edge_2d_sptr inserted)
	replace an edge in a table indexed by vsol id.
static void	LookupTableRemove (vcl_vector< vtol_edge_2d_sptr > &set, vtol_edge_2d_sptr elmt)
	remove an edge from a table indexed by vsol id.
static void	LookupTableCompress (vcl_vector< vtol_edge_2d_sptr > &set)
	eliminate gaps in the table by removing empty entries.
static void	LookupTableInsert (vcl_vector< vtol_vertex_2d_sptr > &set, vtol_vertex_2d_sptr elmt)
	insert a vertex into a table indexed by vsol id.
static void	LookupTableReplace (vcl_vector< vtol_vertex_2d_sptr > &set, vtol_vertex_2d_sptr deleted, vtol_vertex_2d_sptr inserted)
	replace a vertex in a table indexed by vsol id.
static void	LookupTableRemove (vcl_vector< vtol_vertex_2d_sptr > &set, vtol_vertex_2d_sptr elmt)
	remove a vertex from a table indexed by vsol id.
static void	LookupTableCompress (vcl_vector< vtol_vertex_2d_sptr > &set)
	eliminate gaps in the table by removing empty entries.
Protected Attributes
float	minStrength
	class members.
int	minLength
float	minJump
float	max_gap
int	maxSpiral
vbl_array_2d< vtol_edge_2d_sptr > *	edgeMap
vbl_array_2d< vtol_vertex_2d_sptr > *	vertexMap
vcl_vector< vtol_vertex_2d_sptr >	test_verts_