Scale Space - Definition. More...

#include "scalespace.h"
#include "mathop.h"
#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <stdio.h>

Functions
VlScaleSpaceGeometry	vl_scalespace_get_default_geometry (vl_size width, vl_size height)
	Get the default geometry for a given image size. More...

vl_bool	vl_scalespacegeometry_is_equal (VlScaleSpaceGeometry a, VlScaleSpaceGeometry b)
	Check scale space geometries for equality. More...

VlScaleSpaceGeometry	vl_scalespace_get_geometry (VlScaleSpace const *self)
	Get the geometry of the scale space. More...

VlScaleSpaceOctaveGeometry	vl_scalespace_get_octave_geometry (VlScaleSpace const *self, vl_index o)
	Get the geometry of an octave of the scalespace. More...

float *	vl_scalespace_get_level (VlScaleSpace *self, vl_index o, vl_index s)
	Get the data of a scale space level. More...

float const *	vl_scalespace_get_level_const (VlScaleSpace const *self, vl_index o, vl_index s)
	Get the data of a scale space level (const) More...

double	vl_scalespace_get_level_sigma (VlScaleSpace const *self, vl_index o, vl_index s)
	Get the scale of a given octave and sublevel. More...

static void	copy_and_upsample (float destination, float const source, vl_size width, vl_size height)
	Upsample the rows and take the transpose. More...

static void	copy_and_downsample (float destination, float const source, vl_size width, vl_size height, vl_size numOctaves)
	Downsample. More...

VlScaleSpace *	vl_scalespace_new (vl_size width, vl_size height)
	Create a new scale space object. More...

VlScaleSpace *	vl_scalespace_new_with_geometry (VlScaleSpaceGeometry geom)
	Create a new scale space with the specified geometry. More...

VlScaleSpace *	vl_scalespace_new_copy (VlScaleSpace *self)
	Create a new copy of the object. More...

VlScaleSpace *	vl_scalespace_new_shallow_copy (VlScaleSpace *self)
	Create a new shallow copy of the object. More...

void	vl_scalespace_delete (VlScaleSpace *self)
	Delete object. More...

void	_vl_scalespace_fill_octave (VlScaleSpace *self, vl_index o)
	Fill octave starting from the first level. More...

static void	_vl_scalespace_start_octave_from_image (VlScaleSpace self, float const image, vl_index o)
	Initialize the first level of an octave from an image. More...

static void	_vl_scalespace_start_octave_from_previous_octave (VlScaleSpace *self, vl_index o)
	Initialize the first level of an octave from the previous octave. More...

void	vl_scalespace_put_image (VlScaleSpace self, float const image)
	Initialise Scale space with new image. More...

Detailed Description

Author: Karel Lenc; Andrea Vedaldi; Michal Perdoch

Function Documentation

◆ _vl_scalespace_fill_octave()

void _vl_scalespace_fill_octave	(	VlScaleSpace *	self,
		vl_index	o
	)

Parameters

self	object instance.
o	octave to process.

The function takes the first sublevel of octave o (the one at sublevel octaveFirstLevel and iteratively smoothes it to obtain the other octave levels.

◆ _vl_scalespace_start_octave_from_image()

static void _vl_scalespace_start_octave_from_image	(	VlScaleSpace *	self,
		float const *	image,
		vl_index	o
	)

static

Parameters

self	VlScaleSpace object instance.
image	image data.
o	octave to start.

The function initializes the first level of octave o from image image. The dimensions of the image are the ones set during the creation of the VlScaleSpace object instance.

◆ _vl_scalespace_start_octave_from_previous_octave()

static void _vl_scalespace_start_octave_from_previous_octave	(	VlScaleSpace *	self,
		vl_index	o
	)

static

Parameters

self	object.
o	octave to initialize.

The function initializes the first level of octave o from the content of octave o - 1.

◆ copy_and_downsample()

static void copy_and_downsample	(	float *	destination,
		float const *	source,
		vl_size	width,
		vl_size	height,
		vl_size	numOctaves
	)

static

Parameters

destination	output imgae buffer.
source	input image buffer.
width	input image width.
height	input image height.
numOctaves	octaves (non negative).

The function downsamples the image d times, reducing it to 1/2^d of its original size. The parameters width and height are the size of the input image. The destination image dst is assumed to be floor(width/2^d) pixels wide and floor(height/2^d) pixels high.

◆ copy_and_upsample()

static void copy_and_upsample	(	float *	destination,
		float const *	source,
		vl_size	width,
		vl_size	height
	)

static

Parameters

destination	output image.
source	input image.
width	input image width.
height	input image height.

The output image has dimensions height by 2 width (so the destination buffer must be at least as big as two times the input buffer).

Upsampling is performed by linear interpolation.

◆ vl_scalespace_delete()

void vl_scalespace_delete ( VlScaleSpace * self )

Parameters

self	object to delete.

See also: vl_scalespace_new()

◆ vl_scalespace_get_default_geometry()

VlScaleSpaceGeometry vl_scalespace_get_default_geometry	(	vl_size	width,
		vl_size	height
	)

Parameters

width	image width.
height	image height.

Returns: the default scale space geometry.

Both width and height must be at least one pixel wide.

◆ vl_scalespace_get_geometry()

VlScaleSpaceGeometry vl_scalespace_get_geometry ( VlScaleSpace const * self )

Parameters

self object.

Returns: the scale space geometry.

◆ vl_scalespace_get_level()

float* vl_scalespace_get_level	(	VlScaleSpace *	self,
		vl_index	o,
		vl_index	s
	)

Parameters

self	object.
o	octave index.
s	level index.

Returns: pointer to the data for octave o, level s.

The octave index o must be in the range firstOctave to lastOctave and the scale index s must be in the range octaveFirstSubdivision to octaveLastSubdivision.

◆ vl_scalespace_get_level_const()

float const* vl_scalespace_get_level_const	(	VlScaleSpace const *	self,
		vl_index	o,
		vl_index	s
	)

Parameters

self	object.
o	octave index.
s	level index.

Returns: pointer to the data for octave o, level s.

This function is the same as vl_scalespace_get_level but reutrns a const pointer to the data.

◆ vl_scalespace_get_level_sigma()

double vl_scalespace_get_level_sigma	(	VlScaleSpace const *	self,
		vl_index	o,
		vl_index	s
	)

Parameters

self	object.
o	octave index.
s	sublevel index.

The function returns the scale \(\sigma(o,s)\) as a function of the octave index o and sublevel s.

◆ vl_scalespace_get_octave_geometry()

VlScaleSpaceOctaveGeometry vl_scalespace_get_octave_geometry	(	VlScaleSpace const *	self,
		vl_index	o
	)

Parameters

self	object.
o	octave index.

Returns: the geometry of octave o.

◆ vl_scalespace_new()

VlScaleSpace* vl_scalespace_new	(	vl_size	width,
		vl_size	height
	)

Parameters

width	image width.
height	image height.

Returns: new scale space object.

This function is the same as vl_scalespace_new_with_geometry() but it uses vl_scalespace_get_default_geometry to initialise the geometry of the scale space from the image size.

See also: vl_scalespace_new_with_geometry(), vl_scalespace_delete().

◆ vl_scalespace_new_copy()

VlScaleSpace* vl_scalespace_new_copy ( VlScaleSpace * self )

Parameters

self	object to copy from.

The function returns NULL if the copy cannot be made due to an out-of-memory condition.

◆ vl_scalespace_new_shallow_copy()

VlScaleSpace* vl_scalespace_new_shallow_copy ( VlScaleSpace * self )

Parameters

self	object to copy from.

The function works like vl_scalespace_new_copy() but only allocates the scale space, without actually copying the data.

◆ vl_scalespace_new_with_geometry()

VlScaleSpace* vl_scalespace_new_with_geometry ( VlScaleSpaceGeometry geom )

Parameters

geom	scale space geomerty.

Returns: new scale space object.

If the geometry is not valid (see VlScaleSpaceGeometry), the result is unpredictable.

The function returns NULL if it was not possible to allocate the object because of an out-of-memory condition.

See also: VlScaleSpaceGeometry, vl_scalespace_delete().

◆ vl_scalespace_put_image()

void vl_scalespace_put_image	(	VlScaleSpace *	self,
		float const *	image
	)

Parameters

self	VlScaleSpace object instance.
image	image to process.

Compute the data of all the defined octaves and scales of the scale space self.

◆ vl_scalespacegeometry_is_equal()

vl_bool vl_scalespacegeometry_is_equal	(	VlScaleSpaceGeometry	a,
		VlScaleSpaceGeometry	b
	)

Parameters

a	first geometry.
b	second geometry.

Returns: true if equal.

VLFeat.org

Functions

Detailed Description

Function Documentation

◆ _vl_scalespace_fill_octave()

◆ _vl_scalespace_start_octave_from_image()

◆ _vl_scalespace_start_octave_from_previous_octave()

◆ copy_and_downsample()

◆ copy_and_upsample()

◆ vl_scalespace_delete()

◆ vl_scalespace_get_default_geometry()

◆ vl_scalespace_get_geometry()

◆ vl_scalespace_get_level()

◆ vl_scalespace_get_level_const()

◆ vl_scalespace_get_level_sigma()

◆ vl_scalespace_get_octave_geometry()

◆ vl_scalespace_new()

◆ vl_scalespace_new_copy()

◆ vl_scalespace_new_shallow_copy()

◆ vl_scalespace_new_with_geometry()

◆ vl_scalespace_put_image()

◆ vl_scalespacegeometry_is_equal()