itpp::Scalar_Quantizer Class Reference
Source Coding Module » Source Coding Routines

Class for vector quantization. More...

`#include <itpp/srccode/vq.h>`

## Public Member Functions

| Scalar_Quantizer ()
| Default constructor.
| Scalar_Quantizer (const char *Name)
| Create a VQ from a VQ file.
int | encode (double x) const
| Encode.
ivec | encode (const vec &x) const
| Encode the input vector.
double | decode (int Index) const
| Decode the index.
vec | decode (const ivec &Index) const
| Decode the indices.
double | Q (double x) const
| Quantize.
vec | Q (const vec &x) const
| Quantize the input vector.
double | operator() (double x) const
| Quantize.
vec | operator() (const vec &x) const
| Quantize the input vector.
void | set_levels (const vec &L)
| Initialize the codebook by a matrix.
vec | get_levels () const
| Returns the codebook.
int | size () const
| Returns the size (number of codevectors) of the VQ.

## Protected Attributes

vec | Levels
| The vector containing the code book.
double | LatestDist
| The distortion at the latest time a vector was encoded.

## Detailed Description

Class for vector quantization.

The following code illustrates how the quantizer can be initialized from a file and used to quantize a random vector.

Scalar_Quantizer Quantizer;
double x,y;
int i;
Quantizer.load("random.sq");
x=randn();
i=Quantizer.encode(x);
y=Quantizer.decode(i);
itpp::Array
General array class.
Definition array.h:105
itpp::Scalar_Quantizer
Class for vector quantization.
Definition vq.h:153
itpp::randn
double randn(void)
Generates a random Gaussian (0,1) variable.
Definition random.h:831

Definition at line 152 of file vq.h.

## Member Function Documentation

## decode()

double itpp::Scalar_Quantizer::decode | ( | int | Index | ) | const

inline

Decode the index.

Definition at line 189 of file vq.h.

References Levels.

Referenced by Q().

## Q()

double itpp::Scalar_Quantizer::Q | ( | double | x | ) | const

inline

Quantize.

Definition at line 190 of file vq.h.

References decode(), and encode().

Referenced by operator()(), and operator()().

## operator()() [1/2]

double itpp::Scalar_Quantizer::operator() | ( | double | x | ) | const

inline

Quantize.

Definition at line 191 of file vq.h.

References Q().

## operator()() [2/2]

vec itpp::Scalar_Quantizer::operator() | ( | const vec & | x | ) | const

inline

Quantize the input vector.

Definition at line 192 of file vq.h.

References Q().

## set_levels()

void itpp::Scalar_Quantizer::set_levels | ( | const vec & | L | ) |

inline

Initialize the codebook by a matrix.

Definition at line 193 of file vq.h.

References Levels.

## get_levels()

vec itpp::Scalar_Quantizer::get_levels | ( |  | ) | const

inline

Returns the codebook.

Definition at line 194 of file vq.h.

References Levels.

## size()

int itpp::Scalar_Quantizer::size | ( |  | ) | const

inline

Returns the size (number of codevectors) of the VQ.

Definition at line 188 of file vq.h.

References itpp::Array< T >::length(), and Levels.

## Member Data Documentation

## Levels

vec itpp::Scalar_Quantizer::Levels

protected

The vector containing the code book.

Definition at line 183 of file vq.h.

Referenced by decode(), get_levels(), set_levels(), and size().

## LatestDist

double itpp::Scalar_Quantizer::LatestDist

protected

The distortion at the latest time a vector was encoded.

Definition at line 185 of file vq.h.

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

- itpp/srccode/vq.h

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