cvflann::lsh::LshTable< ElementType > Class Template Reference

Lsh hash table. More...

#include <opencv2/flann/lsh_table.h>

Public Types
typedef std::map< BucketKey, Bucket >	BucketsSpace
	A container of all the feature indices. More...
typedef std::vector< Bucket >	BucketsSpeed
	A container of all the feature indices. More...

Public Member Functions
	LshTable ()
	Default constructor. More...
	LshTable (unsigned int feature_size, unsigned int key_size)
	Default constructor Create the mask and allocate the memory. More...
template<>
	LshTable (unsigned int feature_size, unsigned int subsignature_size)
void	add (unsigned int value, const ElementType *feature)
	Add a feature to the table. More...
void	add (Matrix< ElementType > dataset)
	Add a set of features to the table. More...
const Bucket *	getBucketFromKey (BucketKey key) const
	Get a bucket given the key. More...
size_t	getKey (const ElementType *) const
	Compute the sub-signature of a feature. More...
template<>
size_t	getKey (const unsigned char *feature) const
	Return the Subsignature of a feature. More...
LshStats	getStats () const
	Get statistics about the table. More...
template<>
LshStats	getStats () const

Detailed Description

template<typename ElementType>
class cvflann::lsh::LshTable< ElementType >

Lsh hash table.

As its key is a sub-feature, and as usually the size of it is pretty small, we keep it as a continuous memory array. The value is an index in the corpus of features (we keep it as an unsigned int for pure memory reasons, it could be a size_t)

Member Typedef Documentation

BucketsSpace

template<typename ElementType>

typedef std::map<BucketKey, Bucket> cvflann::lsh::LshTable< ElementType >::BucketsSpace

A container of all the feature indices.

Optimized for space

BucketsSpeed

template<typename ElementType>

typedef std::vector<Bucket> cvflann::lsh::LshTable< ElementType >::BucketsSpeed

A container of all the feature indices.

Optimized for speed

Constructor & Destructor Documentation

LshTable() [1/3]

template<typename ElementType>

cvflann::lsh::LshTable< ElementType >::LshTable ( )

inline

Default constructor.

LshTable() [2/3]

template<typename ElementType>

cvflann::lsh::LshTable< ElementType >::LshTable ( unsigned int  feature_size, unsigned int  key_size  )

inline

Default constructor Create the mask and allocate the memory.

Parameters

feature_size	is the size of the feature (considered as a ElementType[])
key_size	is the number of bits that are turned on in the feature

LshTable() [3/3]

template<>

cvflann::lsh::LshTable< unsigned char >::LshTable ( unsigned int  feature_size, unsigned int  subsignature_size  )

inline

References cv::randShuffle().

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Member Function Documentation

add() [1/2]

template<typename ElementType>

void cvflann::lsh::LshTable< ElementType >::add ( unsigned int  value, const ElementType *  feature  )

inline

Add a feature to the table.

Parameters

value	the value to store for that feature
feature	the feature itself

Referenced by cvflann::LshIndex< Distance >::buildIndex().

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add() [2/2]

template<typename ElementType>

void cvflann::lsh::LshTable< ElementType >::add ( Matrix< ElementType >  dataset )

inline

Add a set of features to the table.

Parameters

dataset

the values to store

References cv::add(), and cvflann::Matrix< T >::rows.

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getBucketFromKey()

template<typename ElementType>

const Bucket* cvflann::lsh::LshTable< ElementType >::getBucketFromKey ( BucketKey  key ) const

inline

Get a bucket given the key.

Parameters

key

Returns

getKey() [1/2]

template<typename ElementType>

size_t cvflann::lsh::LshTable< ElementType >::getKey ( const ElementType *  ) const

inline

Compute the sub-signature of a feature.

References CV_Error, cv::max(), cv::min(), and cv::Error::StsBadArg.

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getKey() [2/2]

template<>

size_t cvflann::lsh::LshTable< unsigned char >::getKey ( const unsigned char *  feature ) const

inline

Return the Subsignature of a feature.

Parameters

feature

the feature to analyze

getStats() [1/2]

template<typename ElementType>

LshStats cvflann::lsh::LshTable< ElementType >::getStats

(

)

const

Get statistics about the table.

Returns

getStats() [2/2]

template<>

LshStats cvflann::lsh::LshTable< unsigned char >::getStats ( ) const

inline

References cvflann::lsh::LshStats::bucket_size_max_, cvflann::lsh::LshStats::bucket_size_mean_, cvflann::lsh::LshStats::bucket_size_median_, cvflann::lsh::LshStats::bucket_size_min_, cvflann::lsh::LshStats::bucket_sizes_, cvflann::lsh::LshStats::n_buckets_, cvflann::lsh::LshStats::size_histogram_, and cv::sort().

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

• opencv2/flann/lsh_table.h