com.google.zxing.common.reedsolomon

Class GenericGF

java.lang.Object

com.google.zxing.common.reedsolomon.GenericGF

public final class GenericGF
extends Object

This class contains utility methods for performing mathematical operations over the Galois Fields. Operations use a given primitive polynomial in calculations.

Throughout this package, elements of the GF are represented as an int for convenience and speed (but at the cost of memory).

The size of the GF is assumed to be a power of two.

Author:

Sean Owen, David Olivier

Field Summary

Fields

Modifier and Type	Field and Description
static GenericGF	AZTEC_DATA_10
static GenericGF	AZTEC_DATA_12
static GenericGF	AZTEC_DATA_6
static GenericGF	AZTEC_DATA_8
static GenericGF	AZTEC_PARAM
static GenericGF	DATA_MATRIX_FIELD_256
static GenericGF	MAXICODE_FIELD_64
static GenericGF	QR_CODE_FIELD_256

Constructor Summary

Constructors

Constructor and Description
GenericGF(int primitive, int size, int b) Create a representation of GF(size) using the given primitive polynomial.

Method Summary

Modifier and Type	Method and Description
int	getGeneratorBase()
int	getSize()
String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

AZTEC_DATA_12

public static final GenericGF AZTEC_DATA_12

AZTEC_DATA_10

public static final GenericGF AZTEC_DATA_10

AZTEC_DATA_6

public static final GenericGF AZTEC_DATA_6

AZTEC_PARAM

public static final GenericGF AZTEC_PARAM

QR_CODE_FIELD_256

public static final GenericGF QR_CODE_FIELD_256

DATA_MATRIX_FIELD_256

public static final GenericGF DATA_MATRIX_FIELD_256

AZTEC_DATA_8

public static final GenericGF AZTEC_DATA_8

MAXICODE_FIELD_64

public static final GenericGF MAXICODE_FIELD_64

Constructor Detail

GenericGF

public GenericGF(int primitive,
                 int size,
                 int b)

Create a representation of GF(size) using the given primitive polynomial.

Parameters:

primitive - irreducible polynomial whose coefficients are represented by the bits of an int, where the least-significant bit represents the constant coefficient

size - the size of the field

b - the factor b in the generator polynomial can be 0- or 1-based (g(x) = (x+a^b)(x+a^(b+1))...(x+a^(b+2t-1))). In most cases it should be 1, but for QR code it is 0.

Method Detail

getSize

public int getSize()

getGeneratorBase

public int getGeneratorBase()

toString

public String toString()

Overrides:

toString in class Object