protected internal override int decodeMiddle(BitArray row, int[] startRange, System.Text.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];
int lgPatternFound = 0;
for (int x = 0; x < 6 && rowOffset < end; x++)
{
int bestMatch = decodeDigit(row, counters, rowOffset, L_AND_G_PATTERNS);
result.Append((char)('0' + bestMatch % 10));
for (int i = 0; i < counters.Length; i++)
{
rowOffset += counters[i];
}
if (bestMatch >= 10)
{
lgPatternFound |= 1 << (5 - x);
}
}
determineNumSysAndCheckDigit(result, lgPatternFound);
return(rowOffset);
}
/// <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, System.Text.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
int[] counterDigitPair = new int[10];
int[] counterBlack = new int[5];
int[] 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];
}
}
}
protected internal override int decodeMiddle(BitArray row, int[] startRange, System.Text.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;
}
/// <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> Attempts to decode a single UPC/EAN-encoded digit.
///
/// </summary>
/// <param name="row">row of black/white values to decode
/// </param>
/// <param name="counters">the counts of runs of observed black/white/black/... values
/// </param>
/// <param name="rowOffset">horizontal offset to start decoding from
/// </param>
/// <param name="patterns">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
/// </param>
/// <returns> horizontal offset of first pixel beyond the decoded digit
/// </returns>
/// <throws> ReaderException if digit cannot be decoded </throws>
internal static int decodeDigit(BitArray row, int[] counters, int rowOffset, int[][] patterns)
{
recordPattern(row, rowOffset, counters);
int bestVariance = MAX_AVG_VARIANCE; // worst variance we'll accept
int bestMatch = -1;
int max = patterns.Length;
for (int i = 0; i < max; i++)
{
int[] pattern = patterns[i];
int variance = patternMatchVariance(counters, pattern, MAX_INDIVIDUAL_VARIANCE);
if (variance < bestVariance)
{
bestVariance = variance;
bestMatch = i;
}
}
if (bestMatch >= 0)
{
return(bestMatch);
}
else
{
throw ReaderException.Instance;
}
}
private static int decodeCode(BitArray row, int[] counters, int rowOffset)
{
recordPattern(row, rowOffset, counters);
int bestVariance = MAX_AVG_VARIANCE; // worst variance we'll accept
int bestMatch = -1;
for (int d = 0; d < CODE_PATTERNS.Length; d++)
{
int[] pattern = CODE_PATTERNS[d];
int variance = patternMatchVariance(counters, pattern, MAX_INDIVIDUAL_VARIANCE);
if (variance < bestVariance)
{
bestVariance = variance;
bestMatch = d;
}
}
// TODO We're overlooking the fact that the STOP pattern has 7 values, not 6.
if (bestMatch >= 0)
{
return(bestMatch);
}
else
{
throw ReaderException.Instance;
}
}
protected internal override int decodeMiddle(BitArray row, int[] startRange, System.Text.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];
int lgPatternFound = 0;
for (int x = 0; x < 6 && rowOffset < end; x++)
{
int bestMatch = decodeDigit(row, counters, rowOffset, L_AND_G_PATTERNS);
result.Append((char) ('0' + bestMatch % 10));
for (int i = 0; i < counters.Length; i++)
{
rowOffset += counters[i];
}
if (bestMatch >= 10)
{
lgPatternFound |= 1 << (5 - x);
}
}
determineNumSysAndCheckDigit(result, lgPatternFound);
return rowOffset;
}
protected internal override int decodeMiddle(BitArray row, int[] startRange, System.Text.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);
}
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;
int[] 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(System.Math.Max(0, patternStart - (i - patternStart) / 2), patternStart, false))
{
return(new int[] { 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;
}
/// <param name="row">row of black/white values to search
/// </param>
/// <param name="rowOffset">position to start search
/// </param>
/// <param name="whiteFirst">if true, indicates that the pattern specifies white/black/white/...
/// pixel counts, otherwise, it is interpreted as black/white/black/...
/// </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>
internal static int[] findGuardPattern(BitArray row, int rowOffset, bool whiteFirst, int[] pattern)
{
int patternLength = pattern.Length;
int[] counters = new int[patternLength];
int width = row.Size;
bool isWhite = false;
while (rowOffset < width)
{
isWhite = !row.get_Renamed(rowOffset);
if (whiteFirst == isWhite)
{
break;
}
rowOffset++;
}
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 int[] { 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> <p>Like {@link #decodeRow(int, BitArray, java.util.Hashtable)}, 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.</p>
/// </summary>
public virtual Result decodeRow(int rowNumber, BitArray row, int[] startGuardRange, System.Collections.Hashtable hints)
{
ResultPointCallback resultPointCallback = hints == null?null:(ResultPointCallback)hints[DecodeHintType.NEED_RESULT_POINT_CALLBACK];
if (resultPointCallback != null)
{
resultPointCallback.foundPossibleResultPoint(new ResultPoint((startGuardRange[0] + startGuardRange[1]) / 2.0f, rowNumber));
}
System.Text.StringBuilder result = decodeRowStringBuffer;
result.Length = 0;
int endStart = decodeMiddle(row, startGuardRange, result);
if (resultPointCallback != null)
{
resultPointCallback.foundPossibleResultPoint(new ResultPoint(endStart, rowNumber));
}
int[] endRange = decodeEnd(row, endStart);
if (resultPointCallback != null)
{
resultPointCallback.foundPossibleResultPoint(new ResultPoint((endRange[0] + endRange[1]) / 2.0f, rowNumber));
}
// Make sure there is a quiet zone at least as big as the end pattern after the barcode. The
// spec might want more whitespace, but in practice this is the maximum we can count on.
int end = endRange[1];
int quietEnd = end + (end - endRange[0]);
if (quietEnd >= row.Size || !row.isRange(end, quietEnd, false))
{
throw ReaderException.Instance;
}
System.String resultString = result.ToString();
if (!checkChecksum(resultString))
{
throw ReaderException.Instance;
}
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float left = (float)(startGuardRange[1] + startGuardRange[0]) / 2.0f;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float right = (float)(endRange[1] + endRange[0]) / 2.0f;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
return(new Result(resultString, null, new ResultPoint[] { new ResultPoint(left, (float)rowNumber), new ResultPoint(right, (float)rowNumber) }, BarcodeFormat));
}
/// <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.
this.narrowLineWidth = (startPattern[1] - startPattern[0]) >> 2;
validateQuietZone(row, startPattern[0]);
return(startPattern);
}
/// <summary> Records the size of successive runs of white and black pixels in a row, starting at a given point.
/// The values are recorded in the given array, and the number of runs recorded is equal to the size
/// of the array. If the row starts on a white pixel at the given start point, then the first count
/// recorded is the run of white pixels starting from that point; likewise it is the count of a run
/// of black pixels if the row begin on a black pixels at that point.
///
/// </summary>
/// <param name="row">row to count from
/// </param>
/// <param name="start">offset into row to start at
/// </param>
/// <param name="counters">array into which to record counts
/// </param>
/// <throws> ReaderException if counters cannot be filled entirely from row before running out </throws>
/// <summary> of pixels
/// </summary>
internal static void recordPattern(BitArray row, int start, int[] counters)
{
int numCounters = counters.Length;
for (int i = 0; i < numCounters; i++)
{
counters[i] = 0;
}
int end = row.Size;
if (start >= end)
{
throw ReaderException.Instance;
}
bool isWhite = !row.get_Renamed(start);
int counterPosition = 0;
int i2 = start;
while (i2 < end)
{
bool pixel = row.get_Renamed(i2);
if (pixel ^ isWhite)
{
// that is, exactly one is true
counters[counterPosition]++;
}
else
{
counterPosition++;
if (counterPosition == numCounters)
{
break;
}
else
{
counters[counterPosition] = 1;
isWhite ^= true; // isWhite = !isWhite;
}
}
i2++;
}
// If we read fully the last section of pixels and filled up our counters -- or filled
// the last counter but ran off the side of the image, OK. Otherwise, a problem.
if (!(counterPosition == numCounters || (counterPosition == numCounters - 1 && i2 == end)))
{
throw ReaderException.Instance;
}
}
/// <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;
int[] 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 int[] { 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> 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 = this.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;
}
}
public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable hints)
{
int size = readers.Count;
for (int i = 0; i < size; i++)
{
OneDReader 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, System.Collections.Hashtable hints)
{
int size = readers.Count;
for (int i = 0; i < size; i++)
{
OneDReader reader = (OneDReader)readers[i];
try
{
return(reader.decodeRow(rowNumber, row, hints));
}
catch (ReaderException)
{
// continue
}
}
throw ReaderException.Instance;
}
/// <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);
}
public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable hints)
{
// Find out where the Middle section (payload) starts & ends
int[] startRange = decodeStart(row);
int[] endRange = decodeEnd(row);
System.Text.StringBuilder result = new System.Text.StringBuilder(20);
decodeMiddle(row, startRange[1], endRange[0], result);
System.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;
}
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
return(new Result(resultString, null, new ResultPoint[] { new ResultPoint(startRange[1], (float)rowNumber), new ResultPoint(endRange[0], (float)rowNumber) }, BarcodeFormat.ITF));
}
public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable hints)
{
// Find out where the Middle section (payload) starts & ends
int[] startRange = decodeStart(row);
int[] endRange = decodeEnd(row);
System.Text.StringBuilder result = new System.Text.StringBuilder(20);
decodeMiddle(row, startRange[1], endRange[0], result);
System.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;
}
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
return new Result(resultString, null, new ResultPoint[]{new ResultPoint(startRange[1], (float) rowNumber), new ResultPoint(endRange[0], (float) rowNumber)}, BarcodeFormat.ITF);
}
internal static int[] findStartGuardPattern(BitArray row)
{
bool foundStart = false;
int[] startRange = null;
int nextStart = 0;
while (!foundStart)
{
startRange = findGuardPattern(row, nextStart, false, START_END_PATTERN);
int start = startRange[0];
nextStart = startRange[1];
// Make sure there is a quiet zone at least as big as the start pattern before the barcode.
// If this check would run off the left edge of the image, do not accept this barcode,
// as it is very likely to be a false positive.
int quietStart = start - (nextStart - start);
if (quietStart >= 0)
{
foundStart = row.isRange(quietStart, start, false);
}
}
return startRange;
}
internal static int[] findStartGuardPattern(BitArray row)
{
bool foundStart = false;
int[] startRange = null;
int nextStart = 0;
while (!foundStart)
{
startRange = findGuardPattern(row, nextStart, false, START_END_PATTERN);
int start = startRange[0];
nextStart = startRange[1];
// Make sure there is a quiet zone at least as big as the start pattern before the barcode.
// If this check would run off the left edge of the image, do not accept this barcode,
// as it is very likely to be a false positive.
int quietStart = start - (nextStart - start);
if (quietStart >= 0)
{
foundStart = row.isRange(quietStart, start, false);
}
}
return(startRange);
}
public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable 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++)
{
UPCEANReader 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;
}
public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable 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++)
{
UPCEANReader 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;
}
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;
int[] 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(System.Math.Max(0, patternStart - (i - patternStart) / 2), patternStart, false))
{
return new int[]{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;
}
/// <summary> Attempts to decode a single UPC/EAN-encoded digit.
///
/// </summary>
/// <param name="row">row of black/white values to decode
/// </param>
/// <param name="counters">the counts of runs of observed black/white/black/... values
/// </param>
/// <param name="rowOffset">horizontal offset to start decoding from
/// </param>
/// <param name="patterns">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
/// </param>
/// <returns> horizontal offset of first pixel beyond the decoded digit
/// </returns>
/// <throws> ReaderException if digit cannot be decoded </throws>
internal static int decodeDigit(BitArray row, int[] counters, int rowOffset, int[][] patterns)
{
recordPattern(row, rowOffset, counters);
int bestVariance = MAX_AVG_VARIANCE; // worst variance we'll accept
int bestMatch = - 1;
int max = patterns.Length;
for (int i = 0; i < max; i++)
{
int[] pattern = patterns[i];
int variance = patternMatchVariance(counters, pattern, MAX_INDIVIDUAL_VARIANCE);
if (variance < bestVariance)
{
bestVariance = variance;
bestMatch = i;
}
}
if (bestMatch >= 0)
{
return bestMatch;
}
else
{
throw ReaderException.Instance;
}
}
//UPGRADE_NOTE: Access modifiers of method 'decodeEnd' were changed to 'protected'. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1204'"
protected internal virtual int[] decodeEnd(BitArray row, int endStart)
{
return findGuardPattern(row, endStart, false, START_END_PATTERN);
}
protected internal override int[] decodeEnd(BitArray row, int endStart)
{
return findGuardPattern(row, endStart, true, MIDDLE_END_PATTERN);
}
private static int decodeCode(BitArray row, int[] counters, int rowOffset)
{
recordPattern(row, rowOffset, counters);
int bestVariance = MAX_AVG_VARIANCE; // worst variance we'll accept
int bestMatch = - 1;
for (int d = 0; d < CODE_PATTERNS.Length; d++)
{
int[] pattern = CODE_PATTERNS[d];
int variance = patternMatchVariance(counters, pattern, MAX_INDIVIDUAL_VARIANCE);
if (variance < bestVariance)
{
bestVariance = variance;
bestMatch = d;
}
}
// TODO We're overlooking the fact that the STOP pattern has 7 values, not 6.
if (bestMatch >= 0)
{
return bestMatch;
}
else
{
throw ReaderException.Instance;
}
}
protected internal override int decodeMiddle(BitArray row, int[] startRange, System.Text.StringBuilder resultString)
{
return ean13Reader.decodeMiddle(row, startRange, resultString);
}
//UPGRADE_NOTE: Access modifiers of method 'decodeEnd' were changed to 'protected'. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1204'"
protected internal virtual int[] decodeEnd(BitArray row, int endStart)
{
return(findGuardPattern(row, endStart, false, START_END_PATTERN));
}
/// <summary> We're going to examine rows from the middle outward, searching alternately above and below the
/// middle, and farther out each time. rowStep is the number of rows between each successive
/// attempt above and below the middle. So we'd scan row middle, then middle - rowStep, then
/// middle + rowStep, then middle - (2 * rowStep), etc.
/// rowStep is bigger as the image is taller, but is always at least 1. We've somewhat arbitrarily
/// decided that moving up and down by about 1/16 of the image is pretty good; we try more of the
/// image if "trying harder".
///
/// </summary>
/// <param name="image">The image to decode
/// </param>
/// <param name="hints">Any hints that were requested
/// </param>
/// <returns> The contents of the decoded barcode
/// </returns>
/// <throws> ReaderException Any spontaneous errors which occur </throws>
private Result doDecode(BinaryBitmap image, System.Collections.Hashtable hints)
{
int width = image.Width;
int height = image.Height;
BitArray row = new BitArray(width);
int middle = height >> 1;
bool tryHarder = hints != null && hints.ContainsKey(DecodeHintType.TRY_HARDER);
int rowStep = System.Math.Max(1, height >> (tryHarder?7:4));
int maxLines;
if (tryHarder)
{
maxLines = height; // Look at the whole image, not just the center
}
else
{
maxLines = 9; // Nine rows spaced 1/16 apart is roughly the middle half of the image
}
for (int x = 0; x < maxLines; x++)
{
// Scanning from the middle out. Determine which row we're looking at next:
int rowStepsAboveOrBelow = (x + 1) >> 1;
bool isAbove = (x & 0x01) == 0; // i.e. is x even?
int rowNumber = middle + rowStep * (isAbove?rowStepsAboveOrBelow:- rowStepsAboveOrBelow);
if (rowNumber < 0 || rowNumber >= height)
{
// Oops, if we run off the top or bottom, stop
break;
}
// Estimate black point for this row and load it:
try
{
row = image.getBlackRow(rowNumber, row);
}
catch (ReaderException)
{
continue;
}
// While we have the image data in a BitArray, it's fairly cheap to reverse it in place to
// handle decoding upside down barcodes.
for (int attempt = 0; attempt < 2; attempt++)
{
if (attempt == 1)
{
// trying again?
row.reverse(); // reverse the row and continue
// This means we will only ever draw result points *once* in the life of this method
// since we want to avoid drawing the wrong points after flipping the row, and,
// don't want to clutter with noise from every single row scan -- just the scans
// that start on the center line.
if (hints != null && hints.ContainsKey(DecodeHintType.NEED_RESULT_POINT_CALLBACK))
{
System.Collections.Hashtable newHints = System.Collections.Hashtable.Synchronized(new System.Collections.Hashtable()); // Can't use clone() in J2ME
System.Collections.IEnumerator hintEnum = hints.Keys.GetEnumerator();
//UPGRADE_TODO: Method 'java.util.Enumeration.hasMoreElements' was converted to 'System.Collections.IEnumerator.MoveNext' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javautilEnumerationhasMoreElements'"
while (hintEnum.MoveNext())
{
//UPGRADE_TODO: Method 'java.util.Enumeration.nextElement' was converted to 'System.Collections.IEnumerator.Current' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javautilEnumerationnextElement'"
System.Object key = hintEnum.Current;
if (!key.Equals(DecodeHintType.NEED_RESULT_POINT_CALLBACK))
{
newHints[key] = hints[key];
}
}
hints = newHints;
}
}
try
{
// Look for a barcode
Result result = decodeRow(rowNumber, row, hints);
// We found our barcode
if (attempt == 1)
{
// But it was upside down, so note that
result.putMetadata(ResultMetadataType.ORIENTATION, (System.Object) 180);
// And remember to flip the result points horizontally.
ResultPoint[] points = result.ResultPoints;
points[0] = new ResultPoint(width - points[0].X - 1, points[0].Y);
points[1] = new ResultPoint(width - points[1].X - 1, points[1].Y);
}
return result;
}
catch (ReaderException)
{
// continue -- just couldn't decode this row
}
}
}
throw ReaderException.Instance;
}
public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable 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++;
}
System.Text.StringBuilder result = new System.Text.StringBuilder(20);
int[] 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((System.Char)result[i]);
}
if (total % 43 != ALPHABET_STRING.IndexOf((System.Char)result[max]))
{
throw ReaderException.Instance;
}
result.Remove(max, 1);
}
System.String resultString = result.ToString();
if (extendedMode)
{
resultString = decodeExtended(resultString);
}
if (resultString.Length == 0)
{
// Almost surely a false positive
throw ReaderException.Instance;
}
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float left = (float)(start[1] + start[0]) / 2.0f;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float right = (float)(nextStart + lastStart) / 2.0f;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
return(new Result(resultString, null, new ResultPoint[] { new ResultPoint(left, (float)rowNumber), new ResultPoint(right, (float)rowNumber) }, BarcodeFormat.CODE_39));
}
public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable hints)
{
return(maybeReturnResult(ean13Reader.decodeRow(rowNumber, row, hints)));
}
protected internal override int[] decodeEnd(BitArray row, int endStart)
{
return(findGuardPattern(row, endStart, true, MIDDLE_END_PATTERN));
}
/// <summary> <p>Attempts to decode a one-dimensional barcode format given a single row of
/// an image.</p>
///
/// </summary>
/// <param name="rowNumber">row number from top of the row
/// </param>
/// <param name="row">the black/white pixel data of the row
/// </param>
/// <param name="hints">decode hints
/// </param>
/// <returns> {@link Result} containing encoded string and start/end of barcode
/// </returns>
/// <throws> ReaderException if an error occurs or barcode cannot be found </throws>
public abstract Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable hints);
protected internal override int decodeMiddle(BitArray row, int[] startRange, System.Text.StringBuilder resultString)
{
return(ean13Reader.decodeMiddle(row, startRange, resultString));
}
public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable hints)
{
return maybeReturnResult(ean13Reader.decodeRow(rowNumber, row, hints));
}
private static int[] findStartPattern(BitArray row)
{
int width = row.Size;
int rowOffset = 0;
while (rowOffset < width)
{
if (row.get_Renamed(rowOffset))
{
break;
}
rowOffset++;
}
int counterPosition = 0;
int[] counters = new int[6];
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)
{
int bestVariance = MAX_AVG_VARIANCE;
int bestMatch = - 1;
for (int startCode = CODE_START_A; startCode <= CODE_START_C; startCode++)
{
int variance = patternMatchVariance(counters, CODE_PATTERNS[startCode], MAX_INDIVIDUAL_VARIANCE);
if (variance < bestVariance)
{
bestVariance = variance;
bestMatch = startCode;
}
}
if (bestMatch >= 0)
{
// Look for whitespace before start pattern, >= 50% of width of start pattern
if (row.isRange(System.Math.Max(0, patternStart - (i - patternStart) / 2), patternStart, false))
{
return new int[]{patternStart, i, bestMatch};
}
}
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;
}
private static int[] findStartPattern(BitArray row)
{
int width = row.Size;
int rowOffset = 0;
while (rowOffset < width)
{
if (row.get_Renamed(rowOffset))
{
break;
}
rowOffset++;
}
int counterPosition = 0;
int[] counters = new int[6];
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)
{
int bestVariance = MAX_AVG_VARIANCE;
int bestMatch = -1;
for (int startCode = CODE_START_A; startCode <= CODE_START_C; startCode++)
{
int variance = patternMatchVariance(counters, CODE_PATTERNS[startCode], MAX_INDIVIDUAL_VARIANCE);
if (variance < bestVariance)
{
bestVariance = variance;
bestMatch = startCode;
}
}
if (bestMatch >= 0)
{
// Look for whitespace before start pattern, >= 50% of width of start pattern
if (row.isRange(System.Math.Max(0, patternStart - (i - patternStart) / 2), patternStart, false))
{
return(new int[] { patternStart, i, bestMatch });
}
}
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;
}
public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable hints)
{
int[] startPatternInfo = findStartPattern(row);
int startCode = startPatternInfo[2];
int codeSet;
switch (startCode)
{
case CODE_START_A:
codeSet = CODE_CODE_A;
break;
case CODE_START_B:
codeSet = CODE_CODE_B;
break;
case CODE_START_C:
codeSet = CODE_CODE_C;
break;
default:
throw ReaderException.Instance;
}
bool done = false;
bool isNextShifted = false;
System.Text.StringBuilder result = new System.Text.StringBuilder(20);
int lastStart = startPatternInfo[0];
int nextStart = startPatternInfo[1];
int[] counters = new int[6];
int lastCode = 0;
int code = 0;
int checksumTotal = startCode;
int multiplier = 0;
bool lastCharacterWasPrintable = true;
while (!done)
{
bool unshift = isNextShifted;
isNextShifted = false;
// Save off last code
lastCode = code;
// Decode another code from image
code = decodeCode(row, counters, nextStart);
// Remember whether the last code was printable or not (excluding CODE_STOP)
if (code != CODE_STOP)
{
lastCharacterWasPrintable = true;
}
// Add to checksum computation (if not CODE_STOP of course)
if (code != CODE_STOP)
{
multiplier++;
checksumTotal += multiplier * code;
}
// Advance to where the next code will to start
lastStart = nextStart;
for (int i = 0; i < counters.Length; i++)
{
nextStart += counters[i];
}
// Take care of illegal start codes
switch (code)
{
case CODE_START_A:
case CODE_START_B:
case CODE_START_C:
throw ReaderException.Instance;
}
switch (codeSet)
{
case CODE_CODE_A:
if (code < 64)
{
result.Append((char) (' ' + code));
}
else if (code < 96)
{
result.Append((char) (code - 64));
}
else
{
// Don't let CODE_STOP, which always appears, affect whether whether we think the last
// code was printable or not.
if (code != CODE_STOP)
{
lastCharacterWasPrintable = false;
}
switch (code)
{
case CODE_FNC_1:
case CODE_FNC_2:
case CODE_FNC_3:
case CODE_FNC_4_A:
// do nothing?
break;
case CODE_SHIFT:
isNextShifted = true;
codeSet = CODE_CODE_B;
break;
case CODE_CODE_B:
codeSet = CODE_CODE_B;
break;
case CODE_CODE_C:
codeSet = CODE_CODE_C;
break;
case CODE_STOP:
done = true;
break;
}
}
break;
case CODE_CODE_B:
if (code < 96)
{
result.Append((char) (' ' + code));
}
else
{
if (code != CODE_STOP)
{
lastCharacterWasPrintable = false;
}
switch (code)
{
case CODE_FNC_1:
case CODE_FNC_2:
case CODE_FNC_3:
case CODE_FNC_4_B:
// do nothing?
break;
case CODE_SHIFT:
isNextShifted = true;
codeSet = CODE_CODE_C;
break;
case CODE_CODE_A:
codeSet = CODE_CODE_A;
break;
case CODE_CODE_C:
codeSet = CODE_CODE_C;
break;
case CODE_STOP:
done = true;
break;
}
}
break;
case CODE_CODE_C:
if (code < 100)
{
if (code < 10)
{
result.Append('0');
}
result.Append(code);
}
else
{
if (code != CODE_STOP)
{
lastCharacterWasPrintable = false;
}
switch (code)
{
case CODE_FNC_1:
// do nothing?
break;
case CODE_CODE_A:
codeSet = CODE_CODE_A;
break;
case CODE_CODE_B:
codeSet = CODE_CODE_B;
break;
case CODE_STOP:
done = true;
break;
}
}
break;
}
// Unshift back to another code set if we were shifted
if (unshift)
{
switch (codeSet)
{
case CODE_CODE_A:
codeSet = CODE_CODE_C;
break;
case CODE_CODE_B:
codeSet = CODE_CODE_A;
break;
case CODE_CODE_C:
codeSet = CODE_CODE_B;
break;
}
}
}
// Check for ample whitespace following pattern, but, to do this we first need to remember that
// we fudged decoding CODE_STOP since it actually has 7 bars, not 6. There is a black bar left
// to read off. Would be slightly better to properly read. Here we just skip it:
int width = row.Size;
while (nextStart < width && row.get_Renamed(nextStart))
{
nextStart++;
}
if (!row.isRange(nextStart, System.Math.Min(width, nextStart + (nextStart - lastStart) / 2), false))
{
throw ReaderException.Instance;
}
// Pull out from sum the value of the penultimate check code
checksumTotal -= multiplier * lastCode;
// lastCode is the checksum then:
if (checksumTotal % 103 != lastCode)
{
throw ReaderException.Instance;
}
// Need to pull out the check digits from string
int resultLength = result.Length;
// Only bother if the result had at least one character, and if the checksum digit happened to
// be a printable character. If it was just interpreted as a control code, nothing to remove.
if (resultLength > 0 && lastCharacterWasPrintable)
{
if (codeSet == CODE_CODE_C)
{
result.Remove(resultLength - 2, resultLength - (resultLength - 2));
}
else
{
result.Remove(resultLength - 1, resultLength - (resultLength - 1));
}
}
System.String resultString = result.ToString();
if (resultString.Length == 0)
{
// Almost surely a false positive
throw ReaderException.Instance;
}
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float left = (float) (startPatternInfo[1] + startPatternInfo[0]) / 2.0f;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float right = (float) (nextStart + lastStart) / 2.0f;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
return new Result(resultString, null, new ResultPoint[]{new ResultPoint(left, (float) rowNumber), new ResultPoint(right, (float) rowNumber)}, BarcodeFormat.CODE_128);
}
/// <summary> <p>Attempts to decode a one-dimensional barcode format given a single row of
/// an image.</p>
///
/// </summary>
/// <param name="rowNumber">row number from top of the row
/// </param>
/// <param name="row">the black/white pixel data of the row
/// </param>
/// <param name="hints">decode hints
/// </param>
/// <returns> {@link Result} containing encoded string and start/end of barcode
/// </returns>
/// <throws> ReaderException if an error occurs or barcode cannot be found </throws>
public abstract Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable hints);
/// <summary> Subclasses override this to decode the portion of a barcode between the start
/// and end guard patterns.
///
/// </summary>
/// <param name="row">row of black/white values to search
/// </param>
/// <param name="startRange">start/end offset of start guard pattern
/// </param>
/// <param name="resultString">{@link StringBuffer} to append decoded chars to
/// </param>
/// <returns> horizontal offset of first pixel after the "middle" that was decoded
/// </returns>
/// <throws> ReaderException if decoding could not complete successfully </throws>
protected internal abstract int decodeMiddle(BitArray row, int[] startRange, System.Text.StringBuilder resultString);
/// <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 = this.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;
}
}
public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable hints)
{
return(decodeRow(rowNumber, row, findStartGuardPattern(row), hints));
}
/// <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> <p>Like {@link #decodeRow(int, BitArray, java.util.Hashtable)}, 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.</p>
/// </summary>
public virtual Result decodeRow(int rowNumber, BitArray row, int[] startGuardRange, System.Collections.Hashtable hints)
{
ResultPointCallback resultPointCallback = hints == null?null:(ResultPointCallback) hints[DecodeHintType.NEED_RESULT_POINT_CALLBACK];
if (resultPointCallback != null)
{
resultPointCallback.foundPossibleResultPoint(new ResultPoint((startGuardRange[0] + startGuardRange[1]) / 2.0f, rowNumber));
}
System.Text.StringBuilder result = decodeRowStringBuffer;
result.Length = 0;
int endStart = decodeMiddle(row, startGuardRange, result);
if (resultPointCallback != null)
{
resultPointCallback.foundPossibleResultPoint(new ResultPoint(endStart, rowNumber));
}
int[] endRange = decodeEnd(row, endStart);
if (resultPointCallback != null)
{
resultPointCallback.foundPossibleResultPoint(new ResultPoint((endRange[0] + endRange[1]) / 2.0f, rowNumber));
}
// Make sure there is a quiet zone at least as big as the end pattern after the barcode. The
// spec might want more whitespace, but in practice this is the maximum we can count on.
int end = endRange[1];
int quietEnd = end + (end - endRange[0]);
if (quietEnd >= row.Size || !row.isRange(end, quietEnd, false))
{
throw ReaderException.Instance;
}
System.String resultString = result.ToString();
if (!checkChecksum(resultString))
{
throw ReaderException.Instance;
}
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float left = (float) (startGuardRange[1] + startGuardRange[0]) / 2.0f;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float right = (float) (endRange[1] + endRange[0]) / 2.0f;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
return new Result(resultString, null, new ResultPoint[]{new ResultPoint(left, (float) rowNumber), new ResultPoint(right, (float) rowNumber)}, BarcodeFormat);
}
/// <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();
}
}
/// <param name="row">row of black/white values to search
/// </param>
/// <param name="rowOffset">position to start search
/// </param>
/// <param name="whiteFirst">if true, indicates that the pattern specifies white/black/white/...
/// pixel counts, otherwise, it is interpreted as black/white/black/...
/// </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>
internal static int[] findGuardPattern(BitArray row, int rowOffset, bool whiteFirst, int[] pattern)
{
int patternLength = pattern.Length;
int[] counters = new int[patternLength];
int width = row.Size;
bool isWhite = false;
while (rowOffset < width)
{
isWhite = !row.get_Renamed(rowOffset);
if (whiteFirst == isWhite)
{
break;
}
rowOffset++;
}
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 int[]{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;
}
/// <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;
int[] 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 int[]{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> Subclasses override this to decode the portion of a barcode between the start
/// and end guard patterns.
///
/// </summary>
/// <param name="row">row of black/white values to search
/// </param>
/// <param name="startRange">start/end offset of start guard pattern
/// </param>
/// <param name="resultString">{@link StringBuffer} to append decoded chars to
/// </param>
/// <returns> horizontal offset of first pixel after the "middle" that was decoded
/// </returns>
/// <throws> ReaderException if decoding could not complete successfully </throws>
protected internal abstract int decodeMiddle(BitArray row, int[] startRange, System.Text.StringBuilder resultString);
/// <summary> Records the size of successive runs of white and black pixels in a row, starting at a given point.
/// The values are recorded in the given array, and the number of runs recorded is equal to the size
/// of the array. If the row starts on a white pixel at the given start point, then the first count
/// recorded is the run of white pixels starting from that point; likewise it is the count of a run
/// of black pixels if the row begin on a black pixels at that point.
///
/// </summary>
/// <param name="row">row to count from
/// </param>
/// <param name="start">offset into row to start at
/// </param>
/// <param name="counters">array into which to record counts
/// </param>
/// <throws> ReaderException if counters cannot be filled entirely from row before running out </throws>
/// <summary> of pixels
/// </summary>
internal static void recordPattern(BitArray row, int start, int[] counters)
{
int numCounters = counters.Length;
for (int i = 0; i < numCounters; i++)
{
counters[i] = 0;
}
int end = row.Size;
if (start >= end)
{
throw ReaderException.Instance;
}
bool isWhite = !row.get_Renamed(start);
int counterPosition = 0;
int i2 = start;
while (i2 < end)
{
bool pixel = row.get_Renamed(i2);
if (pixel ^ isWhite)
{
// that is, exactly one is true
counters[counterPosition]++;
}
else
{
counterPosition++;
if (counterPosition == numCounters)
{
break;
}
else
{
counters[counterPosition] = 1;
isWhite ^= true; // isWhite = !isWhite;
}
}
i2++;
}
// If we read fully the last section of pixels and filled up our counters -- or filled
// the last counter but ran off the side of the image, OK. Otherwise, a problem.
if (!(counterPosition == numCounters || (counterPosition == numCounters - 1 && i2 == end)))
{
throw ReaderException.Instance;
}
}
public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable hints)
{
return decodeRow(rowNumber, row, findStartGuardPattern(row), hints);
}
/// <summary> We're going to examine rows from the middle outward, searching alternately above and below the
/// middle, and farther out each time. rowStep is the number of rows between each successive
/// attempt above and below the middle. So we'd scan row middle, then middle - rowStep, then
/// middle + rowStep, then middle - (2 * rowStep), etc.
/// rowStep is bigger as the image is taller, but is always at least 1. We've somewhat arbitrarily
/// decided that moving up and down by about 1/16 of the image is pretty good; we try more of the
/// image if "trying harder".
///
/// </summary>
/// <param name="image">The image to decode
/// </param>
/// <param name="hints">Any hints that were requested
/// </param>
/// <returns> The contents of the decoded barcode
/// </returns>
/// <throws> ReaderException Any spontaneous errors which occur </throws>
private Result doDecode(BinaryBitmap image, System.Collections.Hashtable hints)
{
int width = image.Width;
int height = image.Height;
BitArray row = new BitArray(width);
int middle = height >> 1;
bool tryHarder = hints != null && hints.ContainsKey(DecodeHintType.TRY_HARDER);
int rowStep = System.Math.Max(1, height >> (tryHarder?7:4));
int maxLines;
if (tryHarder)
{
maxLines = height; // Look at the whole image, not just the center
}
else
{
maxLines = 9; // Nine rows spaced 1/16 apart is roughly the middle half of the image
}
for (int x = 0; x < maxLines; x++)
{
// Scanning from the middle out. Determine which row we're looking at next:
int rowStepsAboveOrBelow = (x + 1) >> 1;
bool isAbove = (x & 0x01) == 0; // i.e. is x even?
int rowNumber = middle + rowStep * (isAbove?rowStepsAboveOrBelow:-rowStepsAboveOrBelow);
if (rowNumber < 0 || rowNumber >= height)
{
// Oops, if we run off the top or bottom, stop
break;
}
// Estimate black point for this row and load it:
try
{
row = image.getBlackRow(rowNumber, row);
}
catch (ReaderException)
{
continue;
}
// While we have the image data in a BitArray, it's fairly cheap to reverse it in place to
// handle decoding upside down barcodes.
for (int attempt = 0; attempt < 2; attempt++)
{
if (attempt == 1)
{
// trying again?
row.reverse(); // reverse the row and continue
// This means we will only ever draw result points *once* in the life of this method
// since we want to avoid drawing the wrong points after flipping the row, and,
// don't want to clutter with noise from every single row scan -- just the scans
// that start on the center line.
if (hints != null && hints.ContainsKey(DecodeHintType.NEED_RESULT_POINT_CALLBACK))
{
System.Collections.Hashtable newHints = System.Collections.Hashtable.Synchronized(new System.Collections.Hashtable()); // Can't use clone() in J2ME
System.Collections.IEnumerator hintEnum = hints.Keys.GetEnumerator();
//UPGRADE_TODO: Method 'java.util.Enumeration.hasMoreElements' was converted to 'System.Collections.IEnumerator.MoveNext' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javautilEnumerationhasMoreElements'"
while (hintEnum.MoveNext())
{
//UPGRADE_TODO: Method 'java.util.Enumeration.nextElement' was converted to 'System.Collections.IEnumerator.Current' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javautilEnumerationnextElement'"
System.Object key = hintEnum.Current;
if (!key.Equals(DecodeHintType.NEED_RESULT_POINT_CALLBACK))
{
newHints[key] = hints[key];
}
}
hints = newHints;
}
}
try
{
// Look for a barcode
Result result = decodeRow(rowNumber, row, hints);
// We found our barcode
if (attempt == 1)
{
// But it was upside down, so note that
result.putMetadata(ResultMetadataType.ORIENTATION, (System.Object) 180);
// And remember to flip the result points horizontally.
ResultPoint[] points = result.ResultPoints;
points[0] = new ResultPoint(width - points[0].X - 1, points[0].Y);
points[1] = new ResultPoint(width - points[1].X - 1, points[1].Y);
}
return(result);
}
catch (ReaderException)
{
// continue -- just couldn't decode this row
}
}
}
throw ReaderException.Instance;
}
public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable hints)
{
int[] startPatternInfo = findStartPattern(row);
int startCode = startPatternInfo[2];
int codeSet;
switch (startCode)
{
case CODE_START_A:
codeSet = CODE_CODE_A;
break;
case CODE_START_B:
codeSet = CODE_CODE_B;
break;
case CODE_START_C:
codeSet = CODE_CODE_C;
break;
default:
throw ReaderException.Instance;
}
bool done = false;
bool isNextShifted = false;
System.Text.StringBuilder result = new System.Text.StringBuilder(20);
int lastStart = startPatternInfo[0];
int nextStart = startPatternInfo[1];
int[] counters = new int[6];
int lastCode = 0;
int code = 0;
int checksumTotal = startCode;
int multiplier = 0;
bool lastCharacterWasPrintable = true;
while (!done)
{
bool unshift = isNextShifted;
isNextShifted = false;
// Save off last code
lastCode = code;
// Decode another code from image
code = decodeCode(row, counters, nextStart);
// Remember whether the last code was printable or not (excluding CODE_STOP)
if (code != CODE_STOP)
{
lastCharacterWasPrintable = true;
}
// Add to checksum computation (if not CODE_STOP of course)
if (code != CODE_STOP)
{
multiplier++;
checksumTotal += multiplier * code;
}
// Advance to where the next code will to start
lastStart = nextStart;
for (int i = 0; i < counters.Length; i++)
{
nextStart += counters[i];
}
// Take care of illegal start codes
switch (code)
{
case CODE_START_A:
case CODE_START_B:
case CODE_START_C:
throw ReaderException.Instance;
}
switch (codeSet)
{
case CODE_CODE_A:
if (code < 64)
{
result.Append((char)(' ' + code));
}
else if (code < 96)
{
result.Append((char)(code - 64));
}
else
{
// Don't let CODE_STOP, which always appears, affect whether whether we think the last
// code was printable or not.
if (code != CODE_STOP)
{
lastCharacterWasPrintable = false;
}
switch (code)
{
case CODE_FNC_1:
case CODE_FNC_2:
case CODE_FNC_3:
case CODE_FNC_4_A:
// do nothing?
break;
case CODE_SHIFT:
isNextShifted = true;
codeSet = CODE_CODE_B;
break;
case CODE_CODE_B:
codeSet = CODE_CODE_B;
break;
case CODE_CODE_C:
codeSet = CODE_CODE_C;
break;
case CODE_STOP:
done = true;
break;
}
}
break;
case CODE_CODE_B:
if (code < 96)
{
result.Append((char)(' ' + code));
}
else
{
if (code != CODE_STOP)
{
lastCharacterWasPrintable = false;
}
switch (code)
{
case CODE_FNC_1:
case CODE_FNC_2:
case CODE_FNC_3:
case CODE_FNC_4_B:
// do nothing?
break;
case CODE_SHIFT:
isNextShifted = true;
codeSet = CODE_CODE_C;
break;
case CODE_CODE_A:
codeSet = CODE_CODE_A;
break;
case CODE_CODE_C:
codeSet = CODE_CODE_C;
break;
case CODE_STOP:
done = true;
break;
}
}
break;
case CODE_CODE_C:
if (code < 100)
{
if (code < 10)
{
result.Append('0');
}
result.Append(code);
}
else
{
if (code != CODE_STOP)
{
lastCharacterWasPrintable = false;
}
switch (code)
{
case CODE_FNC_1:
// do nothing?
break;
case CODE_CODE_A:
codeSet = CODE_CODE_A;
break;
case CODE_CODE_B:
codeSet = CODE_CODE_B;
break;
case CODE_STOP:
done = true;
break;
}
}
break;
}
// Unshift back to another code set if we were shifted
if (unshift)
{
switch (codeSet)
{
case CODE_CODE_A:
codeSet = CODE_CODE_C;
break;
case CODE_CODE_B:
codeSet = CODE_CODE_A;
break;
case CODE_CODE_C:
codeSet = CODE_CODE_B;
break;
}
}
}
// Check for ample whitespace following pattern, but, to do this we first need to remember that
// we fudged decoding CODE_STOP since it actually has 7 bars, not 6. There is a black bar left
// to read off. Would be slightly better to properly read. Here we just skip it:
int width = row.Size;
while (nextStart < width && row.get_Renamed(nextStart))
{
nextStart++;
}
if (!row.isRange(nextStart, System.Math.Min(width, nextStart + (nextStart - lastStart) / 2), false))
{
throw ReaderException.Instance;
}
// Pull out from sum the value of the penultimate check code
checksumTotal -= multiplier * lastCode;
// lastCode is the checksum then:
if (checksumTotal % 103 != lastCode)
{
throw ReaderException.Instance;
}
// Need to pull out the check digits from string
int resultLength = result.Length;
// Only bother if the result had at least one character, and if the checksum digit happened to
// be a printable character. If it was just interpreted as a control code, nothing to remove.
if (resultLength > 0 && lastCharacterWasPrintable)
{
if (codeSet == CODE_CODE_C)
{
result.Remove(resultLength - 2, resultLength - (resultLength - 2));
}
else
{
result.Remove(resultLength - 1, resultLength - (resultLength - 1));
}
}
System.String resultString = result.ToString();
if (resultString.Length == 0)
{
// Almost surely a false positive
throw ReaderException.Instance;
}
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float left = (float)(startPatternInfo[1] + startPatternInfo[0]) / 2.0f;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float right = (float)(nextStart + lastStart) / 2.0f;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
return(new Result(resultString, null, new ResultPoint[] { new ResultPoint(left, (float)rowNumber), new ResultPoint(right, (float)rowNumber) }, BarcodeFormat.CODE_128));
}
/// <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, System.Text.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
int[] counterDigitPair = new int[10];
int[] counterBlack = new int[5];
int[] 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];
}
}
}
/// <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.
this.narrowLineWidth = (startPattern[1] - startPattern[0]) >> 2;
validateQuietZone(row, startPattern[0]);
return startPattern;
}
public override Result decodeRow(int rowNumber, BitArray row, System.Collections.Hashtable 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++;
}
System.Text.StringBuilder result = new System.Text.StringBuilder(20);
int[] 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((System.Char) result[i]);
}
if (total % 43 != ALPHABET_STRING.IndexOf((System.Char) result[max]))
{
throw ReaderException.Instance;
}
result.Remove(max, 1);
}
System.String resultString = result.ToString();
if (extendedMode)
{
resultString = decodeExtended(resultString);
}
if (resultString.Length == 0)
{
// Almost surely a false positive
throw ReaderException.Instance;
}
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float left = (float) (start[1] + start[0]) / 2.0f;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float right = (float) (nextStart + lastStart) / 2.0f;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
return new Result(resultString, null, new ResultPoint[]{new ResultPoint(left, (float) rowNumber), new ResultPoint(right, (float) rowNumber)}, BarcodeFormat.CODE_39);
}
