Package com.google.zxing.oned
Class UPCEANReader
java.lang.Object
com.google.zxing.oned.OneDReader
com.google.zxing.oned.UPCEANReader
- All Implemented Interfaces:
Reader
- Direct Known Subclasses:
EAN13Reader
,EAN8Reader
,UPCAReader
,UPCEReader
Encapsulates functionality and implementation that is common to UPC and EAN families of one-dimensional barcodes.
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate final StringBuilder
private final EANManufacturerOrgSupport
(package private) static final int[]
end guard pattern.private final UPCEANExtensionSupport
(package private) static final int[][]
As above but also including the "even", or "G" patterns used to encode UPC/EAN digits.(package private) static final int[][]
"Odd", or "L" patterns used to encode UPC/EAN digits.private static final float
private static final float
(package private) static final int[]
Pattern marking the middle of a UPC/EAN pattern, separating the two halves.(package private) static final int[]
Start/end guard pattern. -
Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescription(package private) boolean
(package private) static boolean
Computes the UPC/EAN checksum on a string of digits, and reports whether the checksum is correct or not.(package private) static int
decodeDigit
(BitArray row, int[] counters, int rowOffset, int[][] patterns) Attempts to decode a single UPC/EAN-encoded digit.(package private) int[]
protected abstract 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.decodeRow
(int rowNumber, BitArray row, int[] startGuardRange, Map<DecodeHintType, ?> hints) LikedecodeRow(int, BitArray, Map)
, but allows caller to inform method about where the UPC/EAN start pattern is found.decodeRow
(int rowNumber, BitArray row, Map<DecodeHintType, ?> hints) Attempts to decode a one-dimensional barcode format given a single row of an image.(package private) static int[]
findGuardPattern
(BitArray row, int rowOffset, boolean whiteFirst, int[] pattern) private static int[]
findGuardPattern
(BitArray row, int rowOffset, boolean whiteFirst, int[] pattern, int[] counters) (package private) static int[]
(package private) abstract BarcodeFormat
Get the format of this decoder.(package private) static int
Methods inherited from class com.google.zxing.oned.OneDReader
decode, decode, patternMatchVariance, recordPattern, recordPatternInReverse, reset
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Field Details
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MAX_AVG_VARIANCE
private static final float MAX_AVG_VARIANCE- See Also:
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MAX_INDIVIDUAL_VARIANCE
private static final float MAX_INDIVIDUAL_VARIANCE- See Also:
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START_END_PATTERN
static final int[] START_END_PATTERNStart/end guard pattern. -
MIDDLE_PATTERN
static final int[] MIDDLE_PATTERNPattern marking the middle of a UPC/EAN pattern, separating the two halves. -
END_PATTERN
static final int[] END_PATTERNend guard pattern. -
L_PATTERNS
static final int[][] L_PATTERNS"Odd", or "L" patterns used to encode UPC/EAN digits. -
L_AND_G_PATTERNS
static final int[][] L_AND_G_PATTERNSAs above but also including the "even", or "G" patterns used to encode UPC/EAN digits. -
decodeRowStringBuffer
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extensionReader
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eanManSupport
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Constructor Details
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UPCEANReader
protected UPCEANReader()
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Method Details
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findStartGuardPattern
- Throws:
NotFoundException
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decodeRow
public Result decodeRow(int rowNumber, BitArray row, Map<DecodeHintType, ?> hints) throws NotFoundException, ChecksumException, FormatExceptionDescription copied from class:OneDReader
Attempts to decode a one-dimensional barcode format given a single row of an image.
- Specified by:
decodeRow
in classOneDReader
- Parameters:
rowNumber
- row number from top of the rowrow
- the black/white pixel data of the rowhints
- decode hints- Returns:
Result
containing encoded string and start/end of barcode- Throws:
NotFoundException
- if no potential barcode is foundChecksumException
- if a potential barcode is found but does not pass its checksumFormatException
- if a potential barcode is found but format is invalid
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decodeRow
public Result decodeRow(int rowNumber, BitArray row, int[] startGuardRange, Map<DecodeHintType, ?> hints) throws NotFoundException, ChecksumException, FormatExceptionLike
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.- Parameters:
rowNumber
- row index into the imagerow
- encoding of the row of the barcode imagestartGuardRange
- start/end column where the opening start pattern was foundhints
- optional hints that influence decoding- Returns:
Result
encapsulating the result of decoding a barcode in the row- Throws:
NotFoundException
- if no potential barcode is foundChecksumException
- if a potential barcode is found but does not pass its checksumFormatException
- if a potential barcode is found but format is invalid
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checkChecksum
- Parameters:
s
- string of digits to check- Returns:
checkStandardUPCEANChecksum(CharSequence)
- Throws:
FormatException
- if the string does not contain only digits
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checkStandardUPCEANChecksum
Computes the UPC/EAN checksum on a string of digits, and reports whether the checksum is correct or not.- Parameters:
s
- string of digits to check- Returns:
- true iff string of digits passes the UPC/EAN checksum algorithm
- Throws:
FormatException
- if the string does not contain only digits
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getStandardUPCEANChecksum
- Throws:
FormatException
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decodeEnd
- Throws:
NotFoundException
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findGuardPattern
static int[] findGuardPattern(BitArray row, int rowOffset, boolean whiteFirst, int[] pattern) throws NotFoundException - Throws:
NotFoundException
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findGuardPattern
private static int[] findGuardPattern(BitArray row, int rowOffset, boolean whiteFirst, int[] pattern, int[] counters) throws NotFoundException - Parameters:
row
- row of black/white values to searchrowOffset
- position to start searchwhiteFirst
- if true, indicates that the pattern specifies white/black/white/... pixel counts, otherwise, it is interpreted as black/white/black/...pattern
- pattern of counts of number of black and white pixels that are being searched for as a patterncounters
- array of counters, as long as pattern, to re-use- Returns:
- start/end horizontal offset of guard pattern, as an array of two ints
- Throws:
NotFoundException
- if pattern is not found
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decodeDigit
static int decodeDigit(BitArray row, int[] counters, int rowOffset, int[][] patterns) throws NotFoundException Attempts to decode a single UPC/EAN-encoded digit.- Parameters:
row
- row of black/white values to decodecounters
- the counts of runs of observed black/white/black/... valuesrowOffset
- horizontal offset to start decoding frompatterns
- the set of patterns to use to decode -- sometimes different encodings for the digits 0-9 are used, and this indicates the encodings for 0 to 9 that should be used- Returns:
- horizontal offset of first pixel beyond the decoded digit
- Throws:
NotFoundException
- if digit cannot be decoded
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getBarcodeFormat
Get the format of this decoder.- Returns:
- The 1D format.
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decodeMiddle
protected abstract int decodeMiddle(BitArray row, int[] startRange, StringBuilder resultString) throws NotFoundException Subclasses override this to decode the portion of a barcode between the start and end guard patterns.- Parameters:
row
- row of black/white values to searchstartRange
- start/end offset of start guard patternresultString
-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
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