lti::orientationFeature Class Reference

The orientation feature takes two channels: a "relevance" channel and an "orientation" channel, and with them it creates an orientation histogram with the given number of cells. More...

#include <ltiOrientationFeature.h>

Inheritance diagram for lti::orientationFeature:

[legend]

Collaboration diagram for lti::orientationFeature:

[legend]

List of all members.

Classes
class	parameters
	the parameters for the class orientationFeature More...
Public Member Functions
	orientationFeature ()
	orientationFeature (const orientationFeature &other)
virtual	~orientationFeature ()
virtual const char *	getTypeName () const
bool	apply (const channel &orientation, const channel &magnitude, dvector &dest) const
orientationFeature &	copy (const orientationFeature &other)
virtual functor *	clone () const
const parameters &	getParameters () const

Detailed Description

The orientation feature takes two channels: a "relevance" channel and an "orientation" channel, and with them it creates an orientation histogram with the given number of cells.

Due to the fact that the orientation is Pi cyclic (0� is the same thing as 180�) the histogram created will consider the angles as being between 0 and Pi (angle mod Pi).

A relevance/orientation pair can be for example the gradient magnitude and phase channels (see lti::gradientKernelX and lti::cartesicToPolar) and the OGD local energy maps (lti::axOGDFeature). Both methods are ready implemented in the lti::orientationMap functor.

 lti::orientationMap omapper;
 lti::orientationFeature ofeat;

 lti::channel chnl,mag,dir;
 lti::vector<double> vct;

 // construct a channel with a rectangle on it:
 chnl.resize(256,256,0.0);
 chnl.fill(1.0,32,32,200,240);

 // extract the orientation map from the channel
 omapper.apply(chnl,dir,mag);

 // generate the orientation feature
 ofeat.apply(dir,mag,vct);

If you need a rotation invariant feature vector see also lti::shiftInvariance

Constructor & Destructor Documentation

lti::orientationFeature::orientationFeature ( )

default constructor

lti::orientationFeature::orientationFeature ( const orientationFeature & other )

copy constructor

Parameters:

other

the object to be copied

virtual lti::orientationFeature::~orientationFeature ( ) [virtual]

destructor

Member Function Documentation

bool lti::orientationFeature::apply	(	const channel &	orientation,
		const channel &	magnitude,
		dvector &	dest
	)			const

generates the "weighted histogram" of the given magnitude and orientations channels.

Parameters:

	orientation	channel with the orientation of edges
	magnitude	channel with the relevance of the orientation.
	dest	the result vector with the histogram data