quickshift.h File Reference

Quick shift (Quick shift image segmentation) More...

#include "generic.h"
#include "mathop.h"

Data Structures
struct	VlQS
	quick shift results More...

Macros
#define	VL_QS_INF   VL_INFINITY_D /* Change to _F for float math */
	quick shift infinity constant

Typedefs
typedef double	vl_qs_type
	quick shift datatype

Functions
Create and destroy
VlQS *	vl_quickshift_new (vl_qs_type const *im, int height, int width, int channels)
	Create a quick shift object.
void	vl_quickshift_delete (VlQS *q)
	Delete quick shift object.
Process data
void	vl_quickshift_process (VlQS *q)
	Create a quick shift objet.
Retrieve data and parameters
vl_qs_type	vl_quickshift_get_max_dist (VlQS const *q)
	Get tau.
vl_qs_type	vl_quickshift_get_kernel_size (VlQS const *q)
	Get sigma.
vl_bool	vl_quickshift_get_medoid (VlQS const *q)
	Get medoid.
int *	vl_quickshift_get_parents (VlQS const *q)
	Get parents.
vl_qs_type *	vl_quickshift_get_dists (VlQS const *q)
	Get dists.
vl_qs_type *	vl_quickshift_get_density (VlQS const *q)
	Get density.
Set parameters
void	vl_quickshift_set_max_dist (VlQS *q, vl_qs_type tau)
	Set max distance.
void	vl_quickshift_set_kernel_size (VlQS *q, vl_qs_type sigma)
	Set sigma.
void	vl_quickshift_set_medoid (VlQS *q, vl_bool medoid)
	Set medoid.

---

Detailed Description

Author:

Andrea Vedaldi

Brian Fulkerson

---

Function Documentation

void vl_quickshift_delete

(

VlQS *

q

)

Parameters:

q	quick shift object.

vl_qs_type * vl_quickshift_get_density ( VlQS const *  q )

inline

Parameters:

q	quick shift object.

Returns:

the estimate of the density at each pixel.

vl_qs_type * vl_quickshift_get_dists ( VlQS const *  q )

inline

Parameters:

q	quick shift object.

Returns:

for each pixel, the distance in feature space to the pixel that is its parent in the quick shift tree. The distance is set to 'inf' if the pixel is a root node.

vl_qs_type vl_quickshift_get_kernel_size ( VlQS const *  q )

inline

Parameters:

q	quick shift object.

Returns:

the standard deviation of the kernel used in the Parzen density estimate.

vl_qs_type vl_quickshift_get_max_dist ( VlQS const *  q )

inline

Parameters:

q	quick shift object.

Returns:

the maximum distance in the feature space between nodes in the quick shift tree.

vl_bool vl_quickshift_get_medoid ( VlQS const *  q )

inline

Parameters:

q	quick Shift object.

Returns:

true if medoid shift is used instead of quick shift.

int * vl_quickshift_get_parents ( VlQS const *  q )

inline

Parameters:

q	quick shift object.

Returns:

a height x width matrix where each element contains the linear index of its parent node. The node is a root if its value is its own linear index.

VlQS* vl_quickshift_new	(	vl_qs_type const *	image,
		int	height,
		int	width,
		int	channels
	)

Parameters:

image	the image.
height	the height (number of rows) of the image.
width	the width (number of columns) of the image.
channels	the number of channels of the image.

Returns:

new quick shift object.

The image is an array of vl_qs_type values with three dimensions (respectively widht, height, and channels). Typically, a color (e.g, RGB) image has three channels. The linear index of a pixel is computed with: channels * width* height + row + height * col.

void vl_quickshift_process

(

VlQS *

q

)

Parameters:

q	quick shift object.

void vl_quickshift_set_kernel_size ( VlQS *  q, vl_qs_type  sigma  )

inline

Parameters:

q	quick shift object.
sigma	standard deviation of the kernel used in the Parzen density estimate.

void vl_quickshift_set_max_dist ( VlQS *  q, vl_qs_type  tau  )

inline

Parameters:

q	quick shift object.
tau	the maximum distance in the feature space between nodes in the quick shift tree.

void vl_quickshift_set_medoid ( VlQS *  q, vl_bool  medoid  )

inline

Parameters:

q	quick shift object.
medoid	true to use kernelized medoid shift, false (default) uses quick shift.