net.semanticmetadata.lire.indexers.hashing

类 LocalitySensitiveHashing

java.lang.Object

net.semanticmetadata.lire.indexers.hashing.LocalitySensitiveHashing

public class LocalitySensitiveHashing
extends java.lang.Object

Each feature vector v with dimension d gets k hashes from a hash bundle h(v) = (h^1(v), h^2(v), ..., h^k(v)) with h^i(v) = (a^i*v + b^i)/w (rounded down), with a^i from R^d and b^i in [0,w)
If m of the k hashes match, then we assume that the feature vectors belong to similar images. Note that m*k has to be bigger than d!
If a^i is drawn from a normal (Gaussian) distribution LSH approximates L2.

Note that this is just to be used with bounded (normalized) descriptors.

作者:

Mathias Lux, mathias@juggle.at Created: 04.06.12, 13:42

字段概要

字段

限定符和类型	字段和说明
static double	binLength
static int	numFunctionBundles

构造器概要

构造器

构造器和说明
LocalitySensitiveHashing()

方法概要

限定符和类型	方法和说明
static int[]	generateHashes(double[] histogram) Generates the hashes from the given hash bundles.
static void	generateHashFunctions() Writes a new file to disk to be read for hashing with LSH.
static void	generateHashFunctions(java.lang.String name)
static void	main(java.lang.String[] args)
static double[][]	readHashFunctions() Reads a file from disk and sets the hash functions.
static double[][]	readHashFunctions(java.io.InputStream in)

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

字段详细资料

numFunctionBundles

public static int numFunctionBundles

binLength

public static double binLength

构造器详细资料

LocalitySensitiveHashing

public LocalitySensitiveHashing()

方法详细资料

generateHashFunctions

public static void generateHashFunctions()
                                  throws java.io.IOException

Writes a new file to disk to be read for hashing with LSH.

抛出:

java.io.IOException

generateHashFunctions

public static void generateHashFunctions(java.lang.String name)
                                  throws java.io.IOException

抛出:

java.io.IOException

readHashFunctions

public static double[][] readHashFunctions()
                                    throws java.io.IOException

Reads a file from disk and sets the hash functions.

返回:

抛出:

java.io.IOException

另请参阅:

generateHashFunctions()

readHashFunctions

public static double[][] readHashFunctions(java.io.InputStream in)
                                    throws java.io.IOException

抛出:

java.io.IOException

generateHashes

public static int[] generateHashes(double[] histogram)

Generates the hashes from the given hash bundles.

参数:

histogram -

返回:

main

public static void main(java.lang.String[] args)