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...

const float *	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()

const float* 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.

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()