#include <vpImageFilter.h>

Static Public Member Functions
static void	filter (const vpImage< double > &I, vpImage< double > &Iu, vpImage< double > &Iv, const vpMatrix &M)

static void	filter (const vpImage< unsigned char > &I, vpImage< double > &If, const vpMatrix &M)

static void	canny (const vpImage< unsigned char > &I, vpImage< unsigned char > &Ic, const unsigned int gaussianFilterSize, const double thresholdCanny, const unsigned int apertureSobel)

template<class T >
static double	gaussianFilter (vpImage< T > &fr, const unsigned int r, const unsigned int c)

template<class T >
static double	derivativeFilterX (vpImage< T > &fr, const unsigned int r, const unsigned int c)

template<class T >
static double	derivativeFilterY (vpImage< T > &fr, const unsigned int r, const unsigned int c)

static void	coefficientGaussianDerivative (double *filter, const unsigned int t)

template<class T >
static double	derivativeFilterX (vpImage< T > &I, const unsigned int r, const unsigned int c, double *filter, const unsigned int size)

template<class T >
static double	derivativeFilterY (vpImage< T > &I, const unsigned int r, const unsigned int c, double *filter, const unsigned int size)

Detailed Description

Various image filter, convolution, etc...

Definition at line 71 of file vpImageFilter.h.

Member Function Documentation

void vpImageFilter::canny	(	const vpImage< unsigned char > &	Isrc,
		vpImage< unsigned char > &	Ires,
		const unsigned int	gaussianFilterSize,
		const double	thresholdCanny,
		const unsigned int	apertureSobel
	)

static

Apply the Canny edge operator on the image Isrc and return the resulting image Ires.

The following example shows how to use the method:

#include <visp/vpConfig.h>
#include <visp/vpImage.h>
#include <visp/vpImageFilter.h>
int main()
{
#if VISP_HAVE_OPENCV_VERSION >= 0x020100 // Cany uses OpenCV v>=2.1.0
  // Constants for the Canny operator.
  const unsigned int gaussianFilterSize = 5;
  const double thresholdCanny = 15;
  const unsigned int apertureSobel = 3;
  // Image for the Canny edge operator
  vpImage<unsigned char> Isrc;
  vpImage<unsigned char> Icanny;
  //First grab the source image Isrc.
  //Apply the Canny edge operator and set the Icanny image.
  vpImageFilter::canny(Isrc, Icanny, gaussianFilterSize, thresholdCanny, apertureSobel);
#endif
  return (0);
}

Parameters

Isrc	: Image to apply the Canny edge detector to.
Ires	: Filtered image (255 means an edge, 0 otherwise).
gaussianFilterSize	: The size of the mask of the Gaussian filter to apply (an odd number).
thresholdCanny	: The threshold for the Canny operator. Only value greater than this value are marked as an edge).
apertureSobel	: Size of the mask for the Sobel operator (odd number).

Definition at line 176 of file vpImageFilter.cpp.

References vpImageConvert::convert().

static void vpImageFilter::coefficientGaussianDerivative	(	double *	filter,
		const unsigned int	t
	)

inlinestatic

build a Gaussian Derivative filter

   \param filter : array (of size t/2) that contains the filter
   \param t : size of the filter

Warning: filter has to be deallocated

Definition at line 163 of file vpImageFilter.h.

References vpMath::sqr().

template<class T >

static double vpImageFilter::derivativeFilterX	(	vpImage< T > &	fr,
		const unsigned int	r,
		const unsigned int	c
	)

inlinestatic

Apply a 1x3 Derivative Filter to an image pixel.

Parameters

fr	: Image to filter
r	coordinates (row) of the pixel
c	: coordinates (column) of the pixel

Definition at line 129 of file vpImageFilter.h.

Referenced by vpFeatureLuminance::buildFrom().

template<class T >

static double vpImageFilter::derivativeFilterX	(	vpImage< T > &	I,
		const unsigned int	r,
		const unsigned int	c,
		double *	filter,
		const unsigned int	size
	)

inlinestatic

Apply a 1 x size Derivative Filter in X to an image pixel.

Parameters

I	: Image to filter
r	: coordinates (row) of the pixel
c	: coordinates (column) of the pixel
filter	: coefficients of the filter to be initialized using vpImageFilter::coefficientGaussianDerivative().
size	: size of the filter

See also: vpImageFilter::coefficientGaussianDerivative()

Definition at line 195 of file vpImageFilter.h.

template<class T >

static double vpImageFilter::derivativeFilterY	(	vpImage< T > &	fr,
		const unsigned int	r,
		const unsigned int	c
	)

inlinestatic

Apply a 3x1 Derivative Filter to an image pixel.

Parameters

fr	: Image to filter
r	: coordinates (row) of the pixel
c	: coordinates (column) of the pixel

Definition at line 146 of file vpImageFilter.h.

Referenced by vpFeatureLuminance::buildFrom().

template<class T >

static double vpImageFilter::derivativeFilterY	(	vpImage< T > &	I,
		const unsigned int	r,
		const unsigned int	c,
		double *	filter,
		const unsigned int	size
	)

inlinestatic

Apply a size x 1 Derivative Filter in Y to an image pixel.

Parameters

I	: Image to filter
r	: coordinates (row) of the pixel
c	: coordinates (column) of the pixel
filter	: coefficients of the filter to be initialized using vpImageFilter::coefficientGaussianDerivative().
size	: size of the filter

See also: vpImageFilter::coefficientGaussianDerivative()

Definition at line 226 of file vpImageFilter.h.

void vpImageFilter::filter	(	const vpImage< double > &	I,
		vpImage< double > &	Iu,
		vpImage< double > &	Iv,
		const vpMatrix &	M
	)

static

Apply a filter to an image.

Parameters

I	: Image to filter
Iu	: Filtered image along the horizontal axis (u = columns).
Iv	: Filtered image along the vertical axis (v = rows).
M	: Separate filter coefficients

Definition at line 99 of file vpImageFilter.cpp.

References vpImage< Type >::getHeight(), vpMatrix::getRows(), vpImage< Type >::getWidth(), and vpImage< Type >::resize().

void vpImageFilter::filter	(	const vpImage< unsigned char > &	I,
		vpImage< double > &	If,
		const vpMatrix &	M
	)

static

Apply a filter to an image.

Parameters

I	: Image to filter
If	: Filtered image.
M	: Filter coefficients.

Definition at line 59 of file vpImageFilter.cpp.

References vpImage< Type >::getHeight(), vpMatrix::getRows(), vpImage< Type >::getWidth(), and vpImage< Type >::resize().

template<class T >

static double vpImageFilter::gaussianFilter	(	vpImage< T > &	fr,
		const unsigned int	r,
		const unsigned int	c
	)

inlinestatic

Apply a 5x5 Gaussian filter to an image pixel.

Parameters

fr	: Image to filter
r	: coordinates (row) of the pixel
c	: coordinates (column) of the pixel

Definition at line 102 of file vpImageFilter.h.

Static Public Member Functions

Detailed Description

Member Function Documentation