latest version v1.9 - last update 24 Nov 2005

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.

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
Classes
class	parameters
	the parameters for the class orientationFeature More...

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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

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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

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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 Returns: true if apply successful or false otherwise.

virtual functor* lti::orientationFeature::clone (   )  const [virtual]

returns a pointer to a clone of this functor. Reimplemented from lti::globalFeatureExtractor.

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

copy data of "other" functor. Parameters: other  the functor to be copied Returns: a reference to this functor object

const parameters& lti::orientationFeature::getParameters (   )  const

returns used parameters Reimplemented from lti::globalFeatureExtractor.

virtual const char* lti::orientationFeature::getTypeName (   )  const [virtual]

returns the name of this type ("orientationFeature") Reimplemented from lti::globalFeatureExtractor.

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

• ltiOrientationFeature.h

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