protected internal override int decodeMiddle(BitArray row, int[] startRange, StringBuilder result)
{
int[] counters = decodeMiddleCounters;
counters[0] = 0;
counters[1] = 0;
counters[2] = 0;
counters[3] = 0;
int end = row.Size;
int rowOffset = startRange[1];
for (int x = 0; x < 4 && rowOffset < end; x++)
{
int bestMatch = decodeDigit(row, counters, rowOffset, L_PATTERNS);
result.Append((char) ('0' + bestMatch));
for (int i = 0; i < counters.Length; i++)
{
rowOffset += counters[i];
}
}
int[] middleRange = findGuardPattern(row, rowOffset, true, MIDDLE_PATTERN);
rowOffset = middleRange[1];
for (int x = 0; x < 4 && rowOffset < end; x++)
{
int bestMatch = decodeDigit(row, counters, rowOffset, L_PATTERNS);
result.Append((char) ('0' + bestMatch));
for (int i = 0; i < counters.Length; i++)
{
rowOffset += counters[i];
}
}
return rowOffset;
}
public override Result decodeRow(int rowNumber, BitArray row, Dictionary<DecodeHintType, Object> hints)
{
int size = readers.Count;
for (int i = 0; i < size; i++)
{
var reader = (OneDReader) readers[i];
try
{
return reader.decodeRow(rowNumber, row, hints);
}
catch (ReaderException)
{
// continue
}
}
throw ReaderException.Instance;
}
public override Result decodeRow(int rowNumber, BitArray row, Dictionary<DecodeHintType, Object> hints)
{
// Find out where the Middle section (payload) starts & ends
int[] startRange = decodeStart(row);
int[] endRange = decodeEnd(row);
var result = new StringBuilder(20);
decodeMiddle(row, startRange[1], endRange[0], result);
String resultString = result.ToString();
int[] allowedLengths = null;
if (hints != null)
{
allowedLengths = (int[]) hints[DecodeHintType.ALLOWED_LENGTHS];
}
if (allowedLengths == null)
{
allowedLengths = DEFAULT_ALLOWED_LENGTHS;
}
// To avoid false positives with 2D barcodes (and other patterns), make
// an assumption that the decoded string must be 6, 10 or 14 digits.
int length = resultString.Length;
bool lengthOK = false;
for (int i = 0; i < allowedLengths.Length; i++)
{
if (length == allowedLengths[i])
{
lengthOK = true;
break;
}
}
if (!lengthOK)
{
throw ReaderException.Instance;
}
return new Result(resultString, null,
new[] {new ResultPoint(startRange[1], rowNumber), new ResultPoint(endRange[0], rowNumber)},
BarcodeFormat.ITF);
}
public override Result decodeRow(int rowNumber, BitArray row, Dictionary<DecodeHintType, Object> hints)
{
// Compute this location once and reuse it on multiple implementations
int[] startGuardPattern = UPCEANReader.findStartGuardPattern(row);
int size = readers.Count;
for (int i = 0; i < size; i++)
{
var reader = (UPCEANReader) readers[i];
Result result;
try
{
result = reader.decodeRow(rowNumber, row, startGuardPattern, hints);
}
catch (ReaderException)
{
continue;
}
// Special case: a 12-digit code encoded in UPC-A is identical to a "0"
// followed by those 12 digits encoded as EAN-13. Each will recognize such a code,
// UPC-A as a 12-digit string and EAN-13 as a 13-digit string starting with "0".
// Individually these are correct and their readers will both read such a code
// and correctly call it EAN-13, or UPC-A, respectively.
//
// In this case, if we've been looking for both types, we'd like to call it
// a UPC-A code. But for efficiency we only run the EAN-13 decoder to also read
// UPC-A. So we special case it here, and convert an EAN-13 result to a UPC-A
// result if appropriate.
if (result.BarcodeFormat.Equals(BarcodeFormat.EAN_13) && result.Text[0] == '0')
{
return new Result(result.Text.Substring(1), null, result.ResultPoints, BarcodeFormat.UPC_A);
}
return result;
}
throw ReaderException.Instance;
}
/// <summary> Converts one row of luminance data to 1 bit data. May actually do the conversion, or return
/// cached data. Callers should assume this method is expensive and call it as seldom as possible.
/// This method is intended for decoding 1D barcodes and may choose to apply sharpening.
///
/// </summary>
/// <param name="y">The row to fetch, 0 <= y < bitmap height.
/// </param>
/// <param name="row">An optional preallocated array. If null or too small, it will be ignored.
/// If used, the Binarizer will call BitArray.clear(). Always use the returned object.
/// </param>
/// <returns> The array of bits for this row (true means black).
/// </returns>
public BitArray getBlackRow(int y, BitArray row)
{
return binarizer.getBlackRow(y, row);
}
/// <summary> A fast method to retrieve one row of data from the matrix as a BitArray.
///
/// </summary>
/// <param name="y">The row to retrieve
/// </param>
/// <param name="row">An optional caller-allocated BitArray, will be allocated if null or too small
/// </param>
/// <returns> The resulting BitArray - this reference should always be used even when passing
/// your own row
/// </returns>
public BitArray getRow(int y, BitArray row)
{
if (row == null || row.Size < width)
{
row = new BitArray(width);
}
int offset = y*rowSize;
for (int x = 0; x < rowSize; x++)
{
row.setBulk(x << 5, bits[offset + x]);
}
return row;
}
protected internal override int decodeMiddle(BitArray row, int[] startRange, StringBuilder resultString)
{
int[] counters = decodeMiddleCounters;
counters[0] = 0;
counters[1] = 0;
counters[2] = 0;
counters[3] = 0;
int end = row.Size;
int rowOffset = startRange[1];
int lgPatternFound = 0;
for (int x = 0; x < 6 && rowOffset < end; x++)
{
int bestMatch = decodeDigit(row, counters, rowOffset, L_AND_G_PATTERNS);
resultString.Append((char) ('0' + bestMatch%10));
for (int i = 0; i < counters.Length; i++)
{
rowOffset += counters[i];
}
if (bestMatch >= 10)
{
lgPatternFound |= 1 << (5 - x);
}
}
determineFirstDigit(resultString, lgPatternFound);
int[] middleRange = findGuardPattern(row, rowOffset, true, MIDDLE_PATTERN);
rowOffset = middleRange[1];
for (int x = 0; x < 6 && rowOffset < end; x++)
{
int bestMatch = decodeDigit(row, counters, rowOffset, L_PATTERNS);
resultString.Append((char) ('0' + bestMatch));
for (int i = 0; i < counters.Length; i++)
{
rowOffset += counters[i];
}
}
return rowOffset;
}
/// <summary> Converts one row of luminance data to 1 bit data. May actually do the conversion, or return /// cached data. Callers should assume this method is expensive and call it as seldom as possible. /// This method is intended for decoding 1D barcodes and may choose to apply sharpening. /// For callers which only examine one row of pixels at a time, the same BitArray should be reused /// and passed in with each call for performance. However it is legal to keep more than one row /// at a time if needed. /// /// </summary> /// <param name="y">The row to fetch, 0 <= y < bitmap height. /// </param> /// <param name="row">An optional preallocated array. If null or too small, it will be ignored. /// If used, the Binarizer will call BitArray.clear(). Always use the returned object. /// </param> /// <returns> The array of bits for this row (true means black). /// </returns> public abstract BitArray getBlackRow(int y, BitArray row);
public override Result decodeRow(int rowNumber, BitArray row, Dictionary<DecodeHintType, Object> hints)
{
int[] start = findAsteriskPattern(row);
int nextStart = start[1];
int end = row.Size;
// Read off white space
while (nextStart < end && !row.get_Renamed(nextStart))
{
nextStart++;
}
var result = new StringBuilder(20);
var counters = new int[9];
char decodedChar;
int lastStart;
do
{
recordPattern(row, nextStart, counters);
int pattern = toNarrowWidePattern(counters);
if (pattern < 0)
{
throw ReaderException.Instance;
}
decodedChar = patternToChar(pattern);
result.Append(decodedChar);
lastStart = nextStart;
for (int i = 0; i < counters.Length; i++)
{
nextStart += counters[i];
}
// Read off white space
while (nextStart < end && !row.get_Renamed(nextStart))
{
nextStart++;
}
} while (decodedChar != '*');
result.Remove(result.Length - 1, 1); // remove asterisk
// Look for whitespace after pattern:
int lastPatternSize = 0;
for (int i = 0; i < counters.Length; i++)
{
lastPatternSize += counters[i];
}
int whiteSpaceAfterEnd = nextStart - lastStart - lastPatternSize;
// If 50% of last pattern size, following last pattern, is not whitespace, fail
// (but if it's whitespace to the very end of the image, that's OK)
if (nextStart != end && whiteSpaceAfterEnd/2 < lastPatternSize)
{
throw ReaderException.Instance;
}
if (usingCheckDigit)
{
int max = result.Length - 1;
int total = 0;
for (int i = 0; i < max; i++)
{
total += ALPHABET_STRING.IndexOf((Char) result[i]);
}
if (total%43 != ALPHABET_STRING.IndexOf((Char) result[max]))
{
throw ReaderException.Instance;
}
result.Remove(max, 1);
}
String resultString = result.ToString();
if (extendedMode)
{
resultString = decodeExtended(resultString);
}
if (resultString.Length == 0)
{
// Almost surely a false positive
throw ReaderException.Instance;
}
float left = (start[1] + start[0])/2.0f;
float right = (nextStart + lastStart)/2.0f;
return new Result(resultString, null,
new[] {new ResultPoint(left, rowNumber), new ResultPoint(right, rowNumber)},
BarcodeFormat.CODE_39);
}
/// <param name="row"> row of black/white values to search
/// </param>
/// <param name="payloadStart">offset of start pattern
/// </param>
/// <param name="resultString">{@link StringBuffer} to append decoded chars to
/// </param>
/// <throws> ReaderException if decoding could not complete successfully </throws>
private static void decodeMiddle(BitArray row, int payloadStart, int payloadEnd, StringBuilder resultString)
{
// Digits are interleaved in pairs - 5 black lines for one digit, and the
// 5
// interleaved white lines for the second digit.
// Therefore, need to scan 10 lines and then
// split these into two arrays
var counterDigitPair = new int[10];
var counterBlack = new int[5];
var counterWhite = new int[5];
while (payloadStart < payloadEnd)
{
// Get 10 runs of black/white.
recordPattern(row, payloadStart, counterDigitPair);
// Split them into each array
for (int k = 0; k < 5; k++)
{
int twoK = k << 1;
counterBlack[k] = counterDigitPair[twoK];
counterWhite[k] = counterDigitPair[twoK + 1];
}
int bestMatch = decodeDigit(counterBlack);
resultString.Append((char) ('0' + bestMatch));
bestMatch = decodeDigit(counterWhite);
resultString.Append((char) ('0' + bestMatch));
for (int i = 0; i < counterDigitPair.Length; i++)
{
payloadStart += counterDigitPair[i];
}
}
}
/// <param name="row"> row of black/white values to search
/// </param>
/// <param name="rowOffset">position to start search
/// </param>
/// <param name="pattern"> pattern of counts of number of black and white pixels that are
/// being searched for as a pattern
/// </param>
/// <returns> start/end horizontal offset of guard pattern, as an array of two
/// ints
/// </returns>
/// <throws> ReaderException if pattern is not found </throws>
private static int[] findGuardPattern(BitArray row, int rowOffset, int[] pattern)
{
// TODO: This is very similar to implementation in UPCEANReader. Consider if they can be
// merged to a single method.
int patternLength = pattern.Length;
var counters = new int[patternLength];
int width = row.Size;
bool isWhite = false;
int counterPosition = 0;
int patternStart = rowOffset;
for (int x = rowOffset; x < width; x++)
{
bool pixel = row.get_Renamed(x);
if (pixel ^ isWhite)
{
counters[counterPosition]++;
}
else
{
if (counterPosition == patternLength - 1)
{
if (patternMatchVariance(counters, pattern, MAX_INDIVIDUAL_VARIANCE) < MAX_AVG_VARIANCE)
{
return new[] {patternStart, x};
}
patternStart += counters[0] + counters[1];
for (int y = 2; y < patternLength; y++)
{
counters[y - 2] = counters[y];
}
counters[patternLength - 2] = 0;
counters[patternLength - 1] = 0;
counterPosition--;
}
else
{
counterPosition++;
}
counters[counterPosition] = 1;
isWhite = !isWhite;
}
}
throw ReaderException.Instance;
}
/// <summary> Identify where the end of the middle / payload section ends.
///
/// </summary>
/// <param name="row">row of black/white values to search
/// </param>
/// <returns> Array, containing index of start of 'end block' and end of 'end
/// block'
/// </returns>
/// <throws> ReaderException </throws>
internal int[] decodeEnd(BitArray row)
{
// For convenience, reverse the row and then
// search from 'the start' for the end block
row.reverse();
try
{
int endStart = skipWhiteSpace(row);
int[] endPattern = findGuardPattern(row, endStart, END_PATTERN_REVERSED);
// The start & end patterns must be pre/post fixed by a quiet zone. This
// zone must be at least 10 times the width of a narrow line.
// ref: http://www.barcode-1.net/i25code.html
validateQuietZone(row, endPattern[0]);
// Now recalculate the indices of where the 'endblock' starts & stops to
// accommodate
// the reversed nature of the search
int temp = endPattern[0];
endPattern[0] = row.Size - endPattern[1];
endPattern[1] = row.Size - temp;
return endPattern;
}
finally
{
// Put the row back the right way.
row.reverse();
}
}
/// <summary> Skip all whitespace until we get to the first black line.
///
/// </summary>
/// <param name="row">row of black/white values to search
/// </param>
/// <returns> index of the first black line.
/// </returns>
/// <throws> ReaderException Throws exception if no black lines are found in the row </throws>
private static int skipWhiteSpace(BitArray row)
{
int width = row.Size;
int endStart = 0;
while (endStart < width)
{
if (row.get_Renamed(endStart))
{
break;
}
endStart++;
}
if (endStart == width)
{
throw ReaderException.Instance;
}
return endStart;
}
/// <summary> The start & end patterns must be pre/post fixed by a quiet zone. This
/// zone must be at least 10 times the width of a narrow line. Scan back until
/// we either get to the start of the barcode or match the necessary number of
/// quiet zone pixels.
///
/// Note: Its assumed the row is reversed when using this method to find
/// quiet zone after the end pattern.
///
/// ref: http://www.barcode-1.net/i25code.html
///
/// </summary>
/// <param name="row">bit array representing the scanned barcode.
/// </param>
/// <param name="startPattern">index into row of the start or end pattern.
/// </param>
/// <throws> ReaderException if the quiet zone cannot be found, a ReaderException is thrown. </throws>
private void validateQuietZone(BitArray row, int startPattern)
{
int quietCount = narrowLineWidth*10; // expect to find this many pixels of quiet zone
for (int i = startPattern - 1; quietCount > 0 && i >= 0; i--)
{
if (row.get_Renamed(i))
{
break;
}
quietCount--;
}
if (quietCount != 0)
{
// Unable to find the necessary number of quiet zone pixels.
throw ReaderException.Instance;
}
}
/// <summary> Identify where the start of the middle / payload section starts.
///
/// </summary>
/// <param name="row">row of black/white values to search
/// </param>
/// <returns> Array, containing index of start of 'start block' and end of
/// 'start block'
/// </returns>
/// <throws> ReaderException </throws>
internal int[] decodeStart(BitArray row)
{
int endStart = skipWhiteSpace(row);
int[] startPattern = findGuardPattern(row, endStart, START_PATTERN);
// Determine the width of a narrow line in pixels. We can do this by
// getting the width of the start pattern and dividing by 4 because its
// made up of 4 narrow lines.
narrowLineWidth = (startPattern[1] - startPattern[0]) >> 2;
validateQuietZone(row, startPattern[0]);
return startPattern;
}
public override Result decodeRow(int rowNumber, BitArray row, Dictionary<DecodeHintType, Object> hints)
{
return maybeReturnResult(ean13Reader.decodeRow(rowNumber, row, hints));
}
protected internal override int decodeMiddle(BitArray row, int[] startRange, StringBuilder resultString)
{
return ean13Reader.decodeMiddle(row, startRange, resultString);
}
private static int[] findAsteriskPattern(BitArray row)
{
int width = row.Size;
int rowOffset = 0;
while (rowOffset < width)
{
if (row.get_Renamed(rowOffset))
{
break;
}
rowOffset++;
}
int counterPosition = 0;
var counters = new int[9];
int patternStart = rowOffset;
bool isWhite = false;
int patternLength = counters.Length;
for (int i = rowOffset; i < width; i++)
{
bool pixel = row.get_Renamed(i);
if (pixel ^ isWhite)
{
counters[counterPosition]++;
}
else
{
if (counterPosition == patternLength - 1)
{
if (toNarrowWidePattern(counters) == ASTERISK_ENCODING)
{
// Look for whitespace before start pattern, >= 50% of width of start pattern
if (row.isRange(Math.Max(0, patternStart - (i - patternStart)/2), patternStart, false))
{
return new[] {patternStart, i};
}
}
patternStart += counters[0] + counters[1];
for (int y = 2; y < patternLength; y++)
{
counters[y - 2] = counters[y];
}
counters[patternLength - 2] = 0;
counters[patternLength - 1] = 0;
counterPosition--;
}
else
{
counterPosition++;
}
counters[counterPosition] = 1;
isWhite = !isWhite;
}
}
throw ReaderException.Instance;
}
