core/vil/algo/vil_gauss_reduce.txx File Reference

Functions to smooth and sub-sample image in one direction. More...

#include "vil_gauss_reduce.h"
#include <vcl_cassert.h>
#include <vil/vil_bilin_interp.h>
#include <vil/vil_plane.h>
#include <vil/vil_convert.h>

Go to the source code of this file.

Defines
#define	vil_gauss_reduce_txx_
#define	VIL_GAUSS_REDUCE_INSTANTIATE(T)
Functions
template<class T >
void	vil_gauss_reduce (const vil_image_view< T > &src_im, vil_image_view< T > &dest_im, vil_image_view< T > &work_im)
	Smooth and subsample src_im to produce dest_im.
template<class T >
void	vil_gauss_reduce_2_3 (const vil_image_view< T > &src_im, vil_image_view< T > &dest_im, vil_image_view< T > &work_im)
	Smooth and subsample src_im to produce dest_im (2/3 size).
template<class T >
void	vil_gauss_reduce_121 (const vil_image_view< T > &src_im, vil_image_view< T > &dest_im)
	Smooth and subsample src_im to produce dest_im.
unsigned char	rl_round (double x, unsigned char)
	An optimisable rounding function.
signed char	rl_round (double x, signed char)
double	rl_round (double x, double)
float	rl_round (double x, float)
template<class T >
void	vil_gauss_reduce_general_plane (const vil_image_view< T > &src, vil_image_view< T > &dest, vil_image_view< T > &worka, vil_image_view< T > &workb, const vil_gauss_reduce_params &params)
	Smooth and subsample src_im to produce dest_im.
template<class T >
void	vil_gauss_reduce_general (const vil_image_view< T > &src, vil_image_view< T > &dest, vil_image_view< T > &worka, vil_image_view< T > &workb, const vil_gauss_reduce_params &params)
	Smooth and subsample src_im by an arbitrary factor to produce dest_im.
template<class T >
void	vil_gauss_reduce_1plane (const T *src_im, unsigned src_ni, unsigned src_nj, vcl_ptrdiff_t s_x_step, vcl_ptrdiff_t s_y_step, T *dest_im, vcl_ptrdiff_t d_x_step, vcl_ptrdiff_t d_y_step)
	Smooth and subsample single plane src_im in x to produce dest_im.
template<class T >
void	vil_gauss_reduce_121_1plane (const T *src_im, unsigned src_ni, unsigned src_nj, vcl_ptrdiff_t s_x_step, vcl_ptrdiff_t s_y_step, T *dest_im, vcl_ptrdiff_t d_x_step, vcl_ptrdiff_t d_y_step)
	Smooth and subsample single plane src_im in x to produce dest_im using 121 filter in x and y.
template<class T >
void	vil_gauss_reduce_2_3_1plane (const T *src_im, unsigned src_ni, unsigned src_nj, vcl_ptrdiff_t s_x_step, vcl_ptrdiff_t s_y_step, T *dest_im, vcl_ptrdiff_t d_x_step, vcl_ptrdiff_t d_y_step)
	Smooth and subsample single plane src_im in x, result is 2/3rd size.

---

Detailed Description

Functions to smooth and sub-sample image in one direction.

Author:

Tim Cootes

Definition in file vil_gauss_reduce.txx.

---

Define Documentation

#define VIL_GAUSS_REDUCE_INSTANTIATE

(

T

)

Value:

template void vil_gauss_reduce(const vil_image_view<T >& src, \
                               vil_image_view<T >& dest, \
                               vil_image_view<T >& work_im); \
template void vil_gauss_reduce_2_3(const vil_image_view<T >& src, \
                                   vil_image_view<T >& dest, \
                                   vil_image_view<T >& work_im); \
template void vil_gauss_reduce_121(const vil_image_view<T >& src, \
                                   vil_image_view<T >& dest); \
template void vil_gauss_reduce_general(const vil_image_view<T >& src_im, \
                                       vil_image_view<T >& dest_im, \
                                       vil_image_view<T >& worka, \
                                       vil_image_view<T >& workb, \
                                       const vil_gauss_reduce_params& params)

Definition at line 463 of file vil_gauss_reduce.txx.

#define vil_gauss_reduce_txx_

Definition at line 3 of file vil_gauss_reduce.txx.

---

Function Documentation

unsigned long rl_round	(	double	x,
		unsigned	char
	)		[inline]

An optimisable rounding function.

Definition at line 120 of file vil_gauss_reduce.txx.

signed long rl_round	(	double	x,
		signed	char
	)		[inline]

Definition at line 123 of file vil_gauss_reduce.txx.

double rl_round	(	double	x,
		double
	)		[inline]

Definition at line 144 of file vil_gauss_reduce.txx.

float rl_round	(	double	x,
		float
	)		[inline]

Definition at line 147 of file vil_gauss_reduce.txx.

template<class T >

void vil_gauss_reduce	(	const vil_image_view< T > &	src_im,
		vil_image_view< T > &	dest_im,
		vil_image_view< T > &	work_im
	)

Smooth and subsample src_im to produce dest_im.

Applies filter in x and y, then samples every other pixel. work_im provides workspace

Definition at line 19 of file vil_gauss_reduce.txx.

template<class T >

void vil_gauss_reduce_121	(	const vil_image_view< T > &	src_im,
		vil_image_view< T > &	dest_im
	)

Smooth and subsample src_im to produce dest_im.

Applies filter in x and y, then samples every other pixel.

Definition at line 94 of file vil_gauss_reduce.txx.

template<class T >

void vil_gauss_reduce_121_1plane	(	const T *	src_im,
		unsigned	src_ni,
		unsigned	src_nj,
		vcl_ptrdiff_t	s_x_step,
		vcl_ptrdiff_t	s_y_step,
		T *	dest_im,
		vcl_ptrdiff_t	d_x_step,
		vcl_ptrdiff_t	d_y_step
	)

Smooth and subsample single plane src_im in x to produce dest_im using 121 filter in x and y.

Smooths with a 3x3 filter and subsamples

Definition at line 328 of file vil_gauss_reduce.txx.

template<class T >

void vil_gauss_reduce_1plane	(	const T *	src_im,
		unsigned	src_nx,
		unsigned	src_ny,
		vcl_ptrdiff_t	s_x_step,
		vcl_ptrdiff_t	s_y_step,
		T *	dest_im,
		vcl_ptrdiff_t	d_x_step,
		vcl_ptrdiff_t	d_y_step
	)

Smooth and subsample single plane src_im in x to produce dest_im.

Applies 1-5-8-5-1 filter in x, then samples every other pixel. Fills [0,(nx+1)/2-1][0,ny-1] elements of dest Assumes dest_im has sufficient data allocated.

This is essentially a utility function, used by mil_gauss_pyramid_builder

By applying twice we can obtain a full gaussian smoothed and sub-sampled 2D image.

Definition at line 281 of file vil_gauss_reduce.txx.

template<class T >

void vil_gauss_reduce_2_3	(	const vil_image_view< T > &	src_im,
		vil_image_view< T > &	dest_im,
		vil_image_view< T > &	work_im
	)

Smooth and subsample src_im to produce dest_im (2/3 size).

Applies filter in x and y, then samples every other pixel. work_im provides workspace

Definition at line 57 of file vil_gauss_reduce.txx.

template<class T >

void vil_gauss_reduce_2_3_1plane	(	const T *	src_im,
		unsigned	src_ni,
		unsigned	src_nj,
		vcl_ptrdiff_t	s_x_step,
		vcl_ptrdiff_t	s_y_step,
		T *	dest_im,
		vcl_ptrdiff_t	d_x_step,
		vcl_ptrdiff_t	d_y_step
	)

Smooth and subsample single plane src_im in x, result is 2/3rd size.

Applies alternate 1-3-1, 1-1 filter in x, then samples every other pixel. Fills [0,(2*ni+1)/3-1][0,nj-1] elements of dest

Note, 131 filter only an approximation

Definition at line 407 of file vil_gauss_reduce.txx.

template<class T >

void vil_gauss_reduce_general	(	const vil_image_view< T > &	src_im,
		vil_image_view< T > &	dest_im,
		vil_image_view< T > &	worka,
		vil_image_view< T > &	workb,
		const vil_gauss_reduce_params &	params
	)

Smooth and subsample src_im by an arbitrary factor to produce dest_im.

Parameters:

worka	provide workspace to avoid repetitive memory alloc and free
workb	provide workspace to avoid repetitive memory alloc and free

Definition at line 252 of file vil_gauss_reduce.txx.

template<class T >

void vil_gauss_reduce_general_plane	(	const vil_image_view< T > &	src,
		vil_image_view< T > &	dest,
		vil_image_view< T > &	worka,
		vil_image_view< T > &	workb,
		const vil_gauss_reduce_params &	params
	)

Smooth and subsample src_im to produce dest_im.

Applies 5 pin filter in x and y, then samples every other pixel. Assumes dest_im has sufficient data allocated

Definition at line 157 of file vil_gauss_reduce.txx.