com.google.zxing

Interface Reader

All Known Implementing Classes:

AbstractRSSReader, AztecReader, ByQuadrantReader, CodaBarReader, Code128Reader, Code39Reader, Code93Reader, DataMatrixReader, EAN13Reader, EAN8Reader, ITFReader, MaxiCodeReader, MultiFormatOneDReader, MultiFormatReader, MultiFormatUPCEANReader, OneDReader, PDF417Reader, QRCodeMultiReader, QRCodeReader, RSS14Reader, RSSExpandedReader, UPCAReader, UPCEANReader, UPCEReader

public interface Reader

Implementations of this interface can decode an image of a barcode in some format into the String it encodes. For example, QRCodeReader can decode a QR code. The decoder may optionally receive hints from the caller which may help it decode more quickly or accurately. See MultiFormatReader, which attempts to determine what barcode format is present within the image as well, and then decodes it accordingly.

Author:

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

Method Summary

Modifier and Type	Method and 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.
void	reset() Resets any internal state the implementation has after a decode, to prepare it for reuse.

Method Detail

decode

Result decode(BinaryBitmap image)
       throws NotFoundException,
              ChecksumException,
              FormatException

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

Parameters:

image - image of barcode to decode

Returns:

String which the barcode encodes

Throws:

NotFoundException - if no potential barcode is found

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

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

decode

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

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.

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

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

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

reset

void reset()

Resets any internal state the implementation has after a decode, to prepare it for reuse.