Package com.google.zxing.datamatrix.decoder

Class Decoder

java.lang.Object

com.google.zxing.datamatrix.decoder.Decoder

public final class Decoder
extends java.lang.Object

The main class which implements Data Matrix Code decoding -- as opposed to locating and extracting the Data Matrix Code from an image.

Field Summary

Fields

Modifier and Type	Field	Description
private ReedSolomonDecoder	rsDecoder

Constructor Summary

Constructors

Constructor	Description
Decoder()

Method Summary

Modifier and Type	Method	Description
private int	correctErrors(byte[] codewordBytes, int numDataCodewords)	Given data and error-correction codewords received, possibly corrupted by errors, attempts to correct the errors in-place using Reed-Solomon error correction.
DecoderResult	decode(boolean[][] image)	Convenience method that can decode a Data Matrix Code represented as a 2D array of booleans.
DecoderResult	decode(BitMatrix bits)	Decodes a Data Matrix Code represented as a BitMatrix.

Methods inherited from class java.lang.Object

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

Field Detail

rsDecoder

private final ReedSolomonDecoder rsDecoder

Constructor Detail

Decoder

public Decoder()

Method Detail

decode

public DecoderResult decode(boolean[][] image)
                     throws FormatException,
                            ChecksumException

Convenience method that can decode a Data Matrix Code represented as a 2D array of booleans. "true" is taken to mean a black module.

Parameters:

image - booleans representing white/black Data Matrix Code modules

Returns:

text and bytes encoded within the Data Matrix Code

Throws:

FormatException - if the Data Matrix Code cannot be decoded

ChecksumException - if error correction fails

decode

public DecoderResult decode(BitMatrix bits)
                     throws FormatException,
                            ChecksumException

Decodes a Data Matrix Code represented as a BitMatrix. A 1 or "true" is taken to mean a black module.

Parameters:

bits - booleans representing white/black Data Matrix Code modules

Returns:

text and bytes encoded within the Data Matrix Code

Throws:

FormatException - if the Data Matrix Code cannot be decoded

ChecksumException - if error correction fails

correctErrors

private int correctErrors(byte[] codewordBytes,
                          int numDataCodewords)
                   throws ChecksumException

Given data and error-correction codewords received, possibly corrupted by errors, attempts to correct the errors in-place using Reed-Solomon error correction.

Parameters:

codewordBytes - data and error correction codewords

numDataCodewords - number of codewords that are data bytes

Returns:

the number of errors corrected

Throws:

ChecksumException - if error correction fails