lti::downsampling Class Reference
[Linear filtering]

This functor is used to downsample images. More...

#include <ltiDownsampling.h>

Inheritance diagram for lti::downsampling:

[legend]

Collaboration diagram for lti::downsampling:

[legend]

List of all members.

Classes
class	parameters
	the parameters for the class downsampling More...
Public Member Functions
	downsampling ()
	downsampling (const parameters &par)
	downsampling (const mathObject &aKernel)
	downsampling (const downsampling &other)
virtual	~downsampling ()
virtual const char *	getTypeName () const
bool	apply (channel8 &srcdest) const
bool	apply (matrix< float > &srcdest) const
bool	apply (dmatrix &srcdest) const
bool	apply (image &srcdest) const
bool	apply (vector< channel8::value_type > &srcdest) const
bool	apply (vector< channel::value_type > &srcdest) const
bool	apply (const channel8 &src, channel8 &dest) const
bool	apply (const matrix< float > &src, matrix< float > &dest) const
bool	apply (const dmatrix &src, dmatrix &dest) const
bool	apply (const image &src, image &dest) const
bool	apply (const vector< channel8::value_type > &src, vector< channel8::value_type > &dest) const
bool	apply (const vector< channel::value_type > &src, vector< channel::value_type > &dest) const
downsampling &	copy (const downsampling &other)
virtual functor *	clone () const
const parameters &	getParameters () const
void	setKernel (const mathObject &aKernel)

---

Detailed Description

This functor is used to downsample images.

Here, the process of downsampling means to first filter the image with (usually) a low pass filter, and then take each n-th pixel, where n is an integer number.

The downsampling::parameters specify which kind of filter should be used and which downsampling factor. If you do not want or need to low-pass filter the image first, than take a look at lti::decimation.

If you need to "downsample" an image with a non-integer factor take a look to lti::scaling.

See also:

lti::decimation, lti::upsampling, lti::filledUpsampling,lti::scaling

Example:

 #include "ltiDownsampling.h"
 #include "ltiGaussKernel2D.h"
   
 lti::channel chnl1,chnl2;
   
 ...
   
 lti::downsampling downsampler;       // downsampling functor
 lti::downsampling::parameters param; // downsampling parameters
   
 // a gaussian kernel to use before the downsampling
 lti::gaussKernel2D<lti::channel::value_type> gkernel;
   
 param.setKernel(gkernel);  // use the gaussian kernel
   
 downsampler.setParameters(param);  // use the given parameters

 downsampler.apply(chnl1,chnl2);  // channel 1 will be downsampled an the
                                  // result will be left on channel 2.

---

Constructor & Destructor Documentation

lti::downsampling::downsampling

(

)

default constructor

lti::downsampling::downsampling

(

const parameters &

par

)

Constructor with parameters object.

lti::downsampling::downsampling

(

const mathObject &

aKernel

)

create a downsampling functor with a parameter set which includes the given filter kernel

lti::downsampling::downsampling

(

const downsampling &

other

)

copy constructor

Parameters:

other

the object to be copied

virtual lti::downsampling::~downsampling

(

)

[virtual]

destructor

---

Member Function Documentation

bool lti::downsampling::apply	(	const vector< channel::value_type > &	src,
		vector< channel::value_type > &	dest
	)			const [virtual]

operates on a copy of the given parameters.

Parameters:

	src	vector<channel::value_type> with the source data.
	dest	vector<channel::value_type> where the result will be left.

Returns:

true if successful, false otherwise.

Reimplemented from lti::modifier.

bool lti::downsampling::apply	(	const vector< channel8::value_type > &	src,
		vector< channel8::value_type > &	dest
	)			const

operates on a copy of the given parameters.

Parameters:

	src	vector<channel8::value_type> with the source data.
	dest	vector<channel8::value_type> where the result will be left.

Returns:

true if successful, false otherwise.

bool lti::downsampling::apply	(	const image &	src,
		image &	dest
	)			const [virtual]

downsample a color image by splitting it into the RGB components, downsampling each channel and merging the results

Parameters:

	src	image with the source data.
	dest	image where the result will be left.

Returns:

true if successful, false otherwise.

Reimplemented from lti::modifier.

bool lti::downsampling::apply	(	const dmatrix &	src,
		dmatrix &	dest
	)			const

operates on a copy of the given parameters.

Parameters:

	src	dmatrix with the source data.
	dest	dmatrix where the result will be left.

Returns:

true if successful, false otherwise.

bool lti::downsampling::apply	(	const matrix< float > &	src,
		matrix< float > &	dest
	)			const [virtual]

operates on a copy of the given parameters.

Parameters:

	src	channel with the source data.
	dest	channel where the result will be left.

Returns:

true if successful, false otherwise.

Reimplemented from lti::modifier.

bool lti::downsampling::apply	(	const channel8 &	src,
		channel8 &	dest
	)			const [virtual]

operates on a copy of the given parameters.

Parameters:

	src	channel8 with the source data.
	dest	channel8 where the result will be left.

Returns:

true if successful, false otherwise.

Reimplemented from lti::modifier.

bool lti::downsampling::apply

(

vector< channel::value_type > &

srcdest

)

const

operates on the given parameter.

Parameters:

srcdest

vector<channel::value_type> with the source data. The result will be left here too.

Returns:

true if successful, false otherwise.

Reimplemented from lti::modifier.

bool lti::downsampling::apply

(

vector< channel8::value_type > &

srcdest

)

const

operates on the given parameter.

Parameters:

srcdest

vector<channel8::value_type> with the source data. The result will be left here too.

Returns:

true if successful, false otherwise.

bool lti::downsampling::apply

(

image &

srcdest

)

const [virtual]

downsample a color image by splitting it into the RGB components, downsampling each channel and merging the results

Parameters:

srcdest

image with the source data. The result will be left here too.

Returns:

true if successful, false otherwise.

Reimplemented from lti::modifier.

bool lti::downsampling::apply

(

dmatrix &

srcdest

)

const

operates on the given parameter.

Parameters:

srcdest

dmatrix with the source data. The result will be left here too.

Returns:

true if successful, false otherwise.

bool lti::downsampling::apply

(

matrix< float > &

srcdest

)

const [virtual]

operates on the given parameter.

Parameters:

srcdest

channel with the source data. The result will be left here too.

Returns:

true if successful, false otherwise.

Reimplemented from lti::modifier.

bool lti::downsampling::apply

(

channel8 &

srcdest

)

const [virtual]

operates on the given parameter.

Parameters:

srcdest

channel8 with the source data. The result will be left here too.

Returns:

true if successful, false otherwise.

Reimplemented from lti::modifier.

virtual functor* lti::downsampling::clone

(

)

const [virtual]

returns a pointer to a clone of this functor.

Implements lti::functor.

downsampling& lti::downsampling::copy

(

const downsampling &

other

)

copy data of "other" functor.

Parameters:

other

the functor to be copied

Returns:

a reference to this functor object

Reimplemented from lti::functor.

const parameters& lti::downsampling::getParameters

(

)

const

returns used parameters

Reimplemented from lti::modifier.

virtual const char* lti::downsampling::getTypeName

(

)

const [virtual]

returns the name of this type ("downsampling")

Reimplemented from lti::modifier.

void lti::downsampling::setKernel

(

const mathObject &

aKernel

)

shortcut to set the filter kernel A copy of the given parameter will be made!

Parameters:

aKernel

the filter kernel to be used

---

The documentation for this class was generated from the following file:

• ltiDownsampling.h