Package com.google.zxing.oned

Class UPCAReader

java.lang.Object

com.google.zxing.oned.OneDReader

com.google.zxing.oned.UPCEANReader

com.google.zxing.oned.UPCAReader

All Implemented Interfaces:

Reader

public final class UPCAReader
extends UPCEANReader

Implements decoding of the UPC-A format.

Author:

dswitkin@google.com (Daniel Switkin), Sean Owen

Constructor Summary

Constructors

Constructor	Description
UPCAReader()

Method Summary

Modifier and Type	Method	Description
Result	decode(BinaryBitmap image)	Locates and decodes a barcode in some format within an image.
Result	decode(BinaryBitmap image, Map<DecodeHintType,?> hints)	Locates and decodes a barcode in some format within an image.
protected int	decodeMiddle(BitArray row, int[] startRange, StringBuilder resultString)	Subclasses override this to decode the portion of a barcode between the start and end guard patterns.
Result	decodeRow(int rowNumber, BitArray row, int[] startGuardRange, Map<DecodeHintType,?> hints)	Like UPCEANReader.decodeRow(int, BitArray, Map), but allows caller to inform method about where the UPC/EAN start pattern is found.
Result	decodeRow(int rowNumber, BitArray row, Map<DecodeHintType,?> hints)	Attempts to decode a one-dimensional barcode format given a single row of an image.

Methods inherited from class com.google.zxing.oned.OneDReader

patternMatchVariance, recordPattern, recordPatternInReverse, reset

Methods inherited from class java.lang.Object

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

Constructor Details

UPCAReader

public UPCAReader()

Method Details

decodeRow

public Result decodeRow(int rowNumber,
 BitArray row,
 int[] startGuardRange,
 Map<DecodeHintType,?> hints)
                 throws NotFoundException,
FormatException,
ChecksumException

Description copied from class: UPCEANReader

Like UPCEANReader.decodeRow(int, BitArray, Map), but allows caller to inform method about where the UPC/EAN start pattern is found. This allows this to be computed once and reused across many implementations.

Overrides:

decodeRow in class UPCEANReader

Parameters:

rowNumber - row index into the image

row - encoding of the row of the barcode image

startGuardRange - start/end column where the opening start pattern was found

hints - optional hints that influence decoding

Returns:

Result encapsulating the result of decoding a barcode in the row

Throws:

NotFoundException - if no potential barcode is found

FormatException - if a potential barcode is found but format is invalid

ChecksumException - if a potential barcode is found but does not pass its checksum

decodeRow

public Result decodeRow(int rowNumber,
 BitArray row,
 Map<DecodeHintType,?> hints)
                 throws NotFoundException,
FormatException,
ChecksumException

Description copied from class: OneDReader

Attempts to decode a one-dimensional barcode format given a single row of an image.

Overrides:

decodeRow in class UPCEANReader

Parameters:

rowNumber - row number from top of the row

row - the black/white pixel data of the row

hints - decode hints

Returns:

Result containing encoded string and start/end of barcode

Throws:

NotFoundException - if no potential barcode is found

FormatException - if a potential barcode is found but format is invalid

ChecksumException - if a potential barcode is found but does not pass its checksum

decode

public Result decode(BinaryBitmap image)
              throws NotFoundException,
FormatException

Description copied from interface: Reader

Locates and decodes a barcode in some format within an image.

Specified by:

decode in interface Reader

Overrides:

decode in class OneDReader

Parameters:

image - image of barcode to decode

Returns:

String which the barcode encodes

Throws:

NotFoundException - if no potential barcode is found

FormatException - if a potential barcode is found but format is invalid

decode

public Result decode(BinaryBitmap image,
 Map<DecodeHintType,?> hints)
              throws NotFoundException,
FormatException

Description copied from interface: Reader

Locates and decodes a barcode in some format within an image. This method also accepts hints, each possibly associated to some data, which may help the implementation decode.

Specified by:

decode in interface Reader

Overrides:

decode in class OneDReader

Parameters:

image - image of barcode to decode

hints - passed as a Map from DecodeHintType to arbitrary data. The meaning of the data depends upon the hint type. The implementation may or may not do anything with these hints.

Returns:

String which the barcode encodes

Throws:

NotFoundException - if no potential barcode is found

FormatException - if a potential barcode is found but format is invalid

decodeMiddle

protected int decodeMiddle(BitArray row,
 int[] startRange,
 StringBuilder resultString)
                    throws NotFoundException

Description copied from class: UPCEANReader

Subclasses override this to decode the portion of a barcode between the start and end guard patterns.

Specified by:

decodeMiddle in class UPCEANReader

Parameters:

row - row of black/white values to search

startRange - start/end offset of start guard pattern

resultString - StringBuilder to append decoded chars to

Returns:

horizontal offset of first pixel after the "middle" that was decoded

Throws:

NotFoundException - if decoding could not complete successfully