#include <osl_canny_rothwell.h>

Inheritance diagram for osl_canny_rothwell:

Public Member Functions
	osl_canny_rothwell (osl_canny_rothwell_params const &)
	~osl_canny_rothwell ()
void	detect_edges (vil1_image const &image, vcl_list< osl_edge * > *, bool adaptive=false)
Protected Member Functions
void	Non_maximal_suppression ()
	Non-maximally suppresses the output image by searching along the edge normal and checking that the test edge has a greater that the interpolated neighbours in the direction.
void	Initial_hysteresis ()
	Hysteresis follows edgel chains that lie above the low_ threshold and have at least one edgel above the high_ threshold.
void	Final_hysteresis (vcl_list< osl_edge * > *)
	Hysteresis follows edgel chains that lie above the low_ threshold and have at least one edgel above the high_ threshold.
void	Jump_gap (int, int, int, int, int , int )
void	Thin_edges ()
	Method to thin the image using the variation of Tsai-Fu thinning used by Van-Duc Nguyen in Geo-Calc.
void	Jump_single_breaks ()
	Searches for single pixel breaks near dangling ends and patches them up.
void	Adaptive_Canny (vil1_image const &)
	Searches for high contrast changes in the vicinity of dangling ends.
void	Compute_adaptive_images (int, int, int, float , float , float **)
void	Subtract_thick (int, int, int, float **)
	Wherever the thick_ image has an edge marked set the new gradient value to zero.
void	Best_eight_way (int, int, float *, int , int *)
	Returns the eight-way neighbour with the strongest contrast change.
void	Find_dangling_ends ()
	Searches for the junctions in the image.
int	Dangling_end (int, int)
	Tests whether a point is a dangling end and return 1 in that case.
void	Find_junctions ()
	Searches for the junctions in the image.
void	Find_junction_clusters ()
	Locate junction clusters using the following method of hysteresis.
void	Final_follow (int, int, vcl_list< int > , vcl_list< int > , vcl_list< float > *, int)
	Following routine looking for connectiveness of edgel chains and accounts for single pixel gaps in the chains.
Static Protected Member Functions
static void	Initial_follow (float const thin, int xsize, int ysize, float low, int x, int y, vcl_list< int > xc, vcl_list< int > yc, vcl_list< float > *grad)
	Following routine looking for connectiveness of edgel chains and accounts for single pixel gaps in the chains.
static void	Follow_junctions (int const junction, int x, int y, vcl_list< int > xc, vcl_list< int > yc)
	Following routine looking for searching out junction clusters.
static void	Cluster_centre_of_gravity (int const jx, int const jy, vcl_list< int > &xc, vcl_list< int > &yc, int &x0, int &y0)
	Finds which member of the lists lies closest to the centre of gravity of the lists.
static int	Junction_neighbour (int const const junction, int x, int y)
	Determines whether the point (x,y) is a neighbour to a junction.
Protected Attributes
int **	dangling_
vcl_list< int > *	xdang_
vcl_list< int > *	ydang_
float	range_
float	old_sigma_
int	old_width_
int	old_k_size_
float	dummy_
unsigned int	xstart_
unsigned int	ystart_
unsigned int	xsize_
unsigned int	ysize_
float **	smooth_
float **	dx_
float **	dy_
float **	grad_
float **	thick_
float **	thin_
float **	theta_
int **	junction_
int **	jx_
int **	jy_
vcl_list< int > *	xjunc_
vcl_list< int > *	yjunc_
vcl_list< osl_Vertex * > *	vlist_
float	gauss_tail_
float	sigma_
int	width_
int	w0_
int	k_size_
float *	kernel_
float	low_
float	high_
float	jval_
int	chain_no_
bool	verbose

Detailed Description

Definition at line 41 of file osl_canny_rothwell.h.

Constructor & Destructor Documentation

osl_canny_rothwell::osl_canny_rothwell ( osl_canny_rothwell_params const & params )

Definition at line 23 of file osl_canny_rothwell.cxx.

osl_canny_rothwell::~osl_canny_rothwell ( )

Definition at line 46 of file osl_canny_rothwell.cxx.

Member Function Documentation

void osl_canny_rothwell::Adaptive_Canny ( vil1_image const & image ) [protected]

Searches for high contrast changes in the vicinity of dangling ends.

This is done by halving the previously used Canny sigma to reduce the effects of smoothing near corners. Ultimately the kernel size will be scaled down until its radius of influence is only two pixels; at that stage pixel-jumping should fix any problems.

Definition at line 654 of file osl_canny_rothwell.cxx.

void osl_canny_rothwell::Best_eight_way	(	int	x,
		int	y,
		float **	grad,
		int *	xnew,
		int *	ynew
	)		`[protected]`

Returns the eight-way neighbour with the strongest contrast change.

fsm: No, this routine returns the last of the eight neighbours with contrast change greater than 'low_'. Probably a bug. FIXME

Definition at line 755 of file osl_canny_rothwell.cxx.

void osl_canny_base::Cluster_centre_of_gravity	(	int const	jx,
		int const	jy,
		vcl_list< int > &	xc,
		vcl_list< int > &	yc,
		int &	x0,
		int &	y0
	)		`[static, protected, inherited]`

Finds which member of the lists lies closest to the centre of gravity of the lists.

Definition at line 206 of file osl_canny_base.cxx.

void osl_canny_rothwell::Compute_adaptive_images	(	int	,
		int	,
		int	,
		float **	,
		float **	,
		float **
	)		`[protected]`

int osl_canny_rothwell::Dangling_end	(	int	x,
		int	y
	)		`[protected]`

Tests whether a point is a dangling end and return 1 in that case.

Otherwise the return value could be 0 or between 2 and 8.

Definition at line 802 of file osl_canny_rothwell.cxx.

void osl_canny_rothwell::detect_edges	(	vil1_image const &	image,
		vcl_list< osl_edge * > *	edges,
		bool	adaptive = `false`
	)

Definition at line 74 of file osl_canny_rothwell.cxx.

void osl_canny_base::Final_follow	(	int	x,
		int	y,
		vcl_list< int > *	xc,
		vcl_list< int > *	yc,
		vcl_list< float > *	grad,
		int	reverse
	)		`[protected, inherited]`

Following routine looking for connectiveness of edgel chains and accounts for single pixel gaps in the chains.

Definition at line 92 of file osl_canny_base.cxx.

void osl_canny_rothwell::Final_hysteresis ( vcl_list< osl_edge * > * edges ) [protected]

Hysteresis follows edgel chains that lie above the low_ threshold and have at least one edgel above the high_ threshold.

Due to the Initial_hysteresis phase, all edges greater than low_ will be by default good and so have a member greater than high_.

Definition at line 360 of file osl_canny_rothwell.cxx.

void osl_canny_rothwell::Find_dangling_ends ( ) [protected]

Searches for the junctions in the image.

Definition at line 778 of file osl_canny_rothwell.cxx.

void osl_canny_rothwell::Find_junction_clusters ( ) [protected]

Locate junction clusters using the following method of hysteresis.

Definition at line 847 of file osl_canny_rothwell.cxx.

void osl_canny_rothwell::Find_junctions ( ) [protected]

Searches for the junctions in the image.

Definition at line 824 of file osl_canny_rothwell.cxx.

void osl_canny_base::Follow_junctions	(	int const	junction,
		int	x,
		int	y,
		vcl_list< int > *	xc,
		vcl_list< int > *	yc
	)		`[static, protected, inherited]`

Following routine looking for searching out junction clusters.

Definition at line 172 of file osl_canny_base.cxx.

void osl_canny_base::Initial_follow	(	float const	thin,
		int	xsize,
		int	ysize,
		float	low,
		int	x,
		int	y,
		vcl_list< int > *	xc,
		vcl_list< int > *	yc,
		vcl_list< float > *	grad
	)		`[static, protected, inherited]`

Following routine looking for connectiveness of edgel chains and accounts for single pixel gaps in the chains.

Definition at line 50 of file osl_canny_base.cxx.

void osl_canny_rothwell::Initial_hysteresis ( ) [protected]

Hysteresis follows edgel chains that lie above the low_ threshold and have at least one edgel above the high_ threshold.

Once we have followed, the good edgelchains are re-written to the thin_ image for further processing.

Definition at line 299 of file osl_canny_rothwell.cxx.

void osl_canny_rothwell::Jump_gap	(	int	,
		int	,
		int	,
		int	,
		int *	,
		int *
	)		`[protected]`

void osl_canny_rothwell::Jump_single_breaks ( ) [protected]

Searches for single pixel breaks near dangling ends and patches them up.

This is destructive on the dangling lists.

Definition at line 571 of file osl_canny_rothwell.cxx.

int osl_canny_base::Junction_neighbour	(	int const const	junction,
		int	x,
		int	y
	)		`[static, protected, inherited]`

Determines whether the point (x,y) is a neighbour to a junction.

Definition at line 252 of file osl_canny_base.cxx.

void osl_canny_rothwell::Non_maximal_suppression ( ) [protected]

Non-maximally suppresses the output image by searching along the edge normal and checking that the test edge has a greater that the interpolated neighbours in the direction.

We have also included sub-pixel interpolation of the peak position by parabolic fitting. Writes edges into the thick_ image.

Definition at line 197 of file osl_canny_rothwell.cxx.

void osl_canny_rothwell::Subtract_thick	(	int	x0,
		int	y0,
		int	image_size,
		float **	grad
	)		`[protected]`

Wherever the thick_ image has an edge marked set the new gradient value to zero.

Definition at line 740 of file osl_canny_rothwell.cxx.

void osl_canny_rothwell::Thin_edges ( ) [protected]

Method to thin the image using the variation of Tsai-Fu thinning used by Van-Duc Nguyen in Geo-Calc.

This relies on computing the genus of an edge location, and removing it if it is not a dangling chain as has genus zero.

Definition at line 519 of file osl_canny_rothwell.cxx.

Member Data Documentation

int osl_canny_base::chain_no_ [protected, inherited]

Definition at line 89 of file osl_canny_base.h.

int** osl_canny_rothwell::dangling_ [protected]

Definition at line 65 of file osl_canny_rothwell.h.

float osl_canny_rothwell::dummy_ [protected]

Definition at line 74 of file osl_canny_rothwell.h.

float** osl_canny_base::dx_ [protected, inherited]

Definition at line 64 of file osl_canny_base.h.

float** osl_canny_base::dy_ [protected, inherited]

Definition at line 65 of file osl_canny_base.h.

float osl_canny_base::gauss_tail_ [protected, inherited]

Definition at line 79 of file osl_canny_base.h.

float** osl_canny_base::grad_ [protected, inherited]

Definition at line 66 of file osl_canny_base.h.

float osl_canny_base::high_ [protected, inherited]

Definition at line 86 of file osl_canny_base.h.

int** osl_canny_base::junction_ [protected, inherited]

Definition at line 73 of file osl_canny_base.h.

float osl_canny_base::jval_ [protected, inherited]

Definition at line 88 of file osl_canny_base.h.

int** osl_canny_base::jx_ [protected, inherited]

Definition at line 74 of file osl_canny_base.h.

int ** osl_canny_base::jy_ [protected, inherited]

Definition at line 74 of file osl_canny_base.h.

int osl_canny_base::k_size_ [protected, inherited]

Definition at line 83 of file osl_canny_base.h.

float* osl_canny_base::kernel_ [protected, inherited]

Definition at line 84 of file osl_canny_base.h.

float osl_canny_base::low_ [protected, inherited]

Definition at line 85 of file osl_canny_base.h.

int osl_canny_rothwell::old_k_size_ [protected]

Definition at line 72 of file osl_canny_rothwell.h.

float osl_canny_rothwell::old_sigma_ [protected]

Definition at line 70 of file osl_canny_rothwell.h.

int osl_canny_rothwell::old_width_ [protected]

Definition at line 71 of file osl_canny_rothwell.h.

float osl_canny_rothwell::range_ [protected]

Definition at line 67 of file osl_canny_rothwell.h.

float osl_canny_base::sigma_ [protected, inherited]

Definition at line 80 of file osl_canny_base.h.

float** osl_canny_base::smooth_ [protected, inherited]

Definition at line 63 of file osl_canny_base.h.

float** osl_canny_base::theta_ [protected, inherited]

Definition at line 70 of file osl_canny_base.h.

float** osl_canny_base::thick_ [protected, inherited]

Definition at line 68 of file osl_canny_base.h.

float** osl_canny_base::thin_ [protected, inherited]

Definition at line 69 of file osl_canny_base.h.

bool osl_canny_base::verbose [protected, inherited]

Definition at line 90 of file osl_canny_base.h.

vcl_list<osl_Vertex*>* osl_canny_base::vlist_ [protected, inherited]

Definition at line 77 of file osl_canny_base.h.

int osl_canny_base::w0_ [protected, inherited]

Definition at line 82 of file osl_canny_base.h.

int osl_canny_base::width_ [protected, inherited]

Definition at line 81 of file osl_canny_base.h.

vcl_list<int>* osl_canny_rothwell::xdang_ [protected]

Definition at line 66 of file osl_canny_rothwell.h.

vcl_list<int>* osl_canny_base::xjunc_ [protected, inherited]

Definition at line 75 of file osl_canny_base.h.

unsigned int osl_canny_base::xsize_ [protected, inherited]

Definition at line 61 of file osl_canny_base.h.

unsigned int osl_canny_base::xstart_ [protected, inherited]

Definition at line 60 of file osl_canny_base.h.

vcl_list<int> * osl_canny_rothwell::ydang_ [protected]

Definition at line 66 of file osl_canny_rothwell.h.

vcl_list<int>* osl_canny_base::yjunc_ [protected, inherited]

Definition at line 76 of file osl_canny_base.h.

unsigned int osl_canny_base::ysize_ [protected, inherited]

Definition at line 61 of file osl_canny_base.h.

unsigned int osl_canny_base::ystart_ [protected, inherited]

Definition at line 60 of file osl_canny_base.h.

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

contrib/oxl/osl/osl_canny_rothwell.h
contrib/oxl/osl/osl_canny_rothwell.cxx

Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation