core/vil/algo/vil_find_peaks.h File Reference

---

Detailed Description

Find peaks in image.

Author:

Tim Cootes

Definition in file vil_find_peaks.h.

#include <vil/vil_image_view.h>
#include <vcl_vector.h>

Go to the source code of this file.

Functions
template<class T>
bool	vil_is_peak_3x3 (const T *im, vcl_ptrdiff_t i_step, vcl_ptrdiff_t j_step)
	True if pixel at *im is strictly above 8 neighbours.
template<class T>
void	vil_find_peaks_3x3 (vcl_vector< unsigned > &pi, vcl_vector< unsigned > &pj, const vil_image_view< T > &image, const T &min_thresh, bool clear_list=true)
	Return (pi,pj) for all points in image strictly above their 8 neighbours.
template<class T>
bool	vil_interpolate_peak (const T *pixel, vcl_ptrdiff_t istep, vcl_ptrdiff_t jstep, double &dx, double &dy, double &val)
	Fit a paraboloid to a pixel and its 8 neighbors to iterpolate the peak.
template<class T>
void	vil_find_peaks_3x3_subpixel (vcl_vector< double > &px, vcl_vector< double > &py, vcl_vector< double > &val, const vil_image_view< T > &image, const T &min_thresh, bool clear_list=true)
	Return sub-pixel (px,py,val) for all points in image strictly above their 8 neighbours.

---

Function Documentation

template<class T>

void vil_find_peaks_3x3	(	vcl_vector< unsigned > &	pi,
		vcl_vector< unsigned > &	pj,
		const vil_image_view< T > &	image,
		const T &	min_thresh,
		bool	clear_list = true
	)			[inline]

Return (pi,pj) for all points in image strictly above their 8 neighbours.

Compute position of all local peaks (pi[k],pj[k]) above given threshold value.

Parameters:

clear_list

If true (the default) then empty lists before adding new examples

See also:

vil_find_plateaus_3x3()

Definition at line 34 of file vil_find_peaks.h.

template<class T>

void vil_find_peaks_3x3_subpixel	(	vcl_vector< double > &	px,
		vcl_vector< double > &	py,
		vcl_vector< double > &	val,
		const vil_image_view< T > &	image,
		const T &	min_thresh,
		bool	clear_list = true
	)			[inline]

Return sub-pixel (px,py,val) for all points in image strictly above their 8 neighbours.

Interpolation sub-pixel position of all local peaks (px[k],py[k]) above given threshold value by fitting a parabaloid. Interpolated peak values are returned in val.

Parameters:

clear_list

If true (the default) then empty lists before adding new examples.

Definition at line 143 of file vil_find_peaks.h.

template<class T>

bool vil_interpolate_peak	(	const T *	pixel,
		vcl_ptrdiff_t	istep,
		vcl_ptrdiff_t	jstep,
		double &	dx,
		double &	dy,
		double &	val
	)

Fit a paraboloid to a pixel and its 8 neighbors to iterpolate the peak.

Returns:

true if the neighborhood produces a proper peak (not a saddle) return by reference the sub-pixel offsets from the pixel center dx and dy as well as the interpolated peak value val.

Definition at line 62 of file vil_find_peaks.h.

template<class T>

bool vil_is_peak_3x3	(	const T *	im,
		vcl_ptrdiff_t	i_step,
		vcl_ptrdiff_t	j_step
	)			[inline]

True if pixel at *im is strictly above 8 neighbours.

See also:

vil_is_plateau_3x3()

Definition at line 15 of file vil_find_peaks.h.

---