| public getNextUnset ( int from ) : int | ||
| from | int | index to start looking for unset bit |
| return | int | |
override public Result decodeRow(int rowNumber, BitArray row, IDictionary<DecodeHintType, object> hints)
{
int[] startPatternInfo = findStartPattern(row);
if (startPatternInfo == null)
return null;
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:
return null;
}
bool done = false;
bool isNextShifted = false;
var result = new StringBuilder(20);
var rawCodes = new List<byte>(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
if (!decodeCode(row, counters, nextStart, out code))
return null;
rawCodes.Add((byte)code);
// 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;
foreach (int counter in counters)
{
nextStart += counter;
}
// Take care of illegal start codes
switch (code)
{
case CODE_START_A:
case CODE_START_B:
case CODE_START_C:
return null;
}
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:
if (result.Length == 0)
{
// GS1 specification 5.4.3.7. and 5.4.6.4. If the first char after the start code
// is FNC1 then this is GS1-128. We add the symbology identifier.
result.Append("]C1");
}
else
{
// GS1 specification 5.4.7.5. Every subsequent FNC1 is returned as ASCII 29 (GS)
result.Append((char)29);
}
break;
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_A;
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)
{
codeSet = codeSet == CODE_CODE_A ? CODE_CODE_B : CODE_CODE_A;
}
}
// 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:
nextStart = row.getNextUnset(nextStart);
if (!row.isRange(nextStart,
Math.Min(row.Size, nextStart + (nextStart - lastStart) / 2),
false))
{
return null;
}
// Pull out from sum the value of the penultimate check code
checksumTotal -= multiplier * lastCode;
// lastCode is the checksum then:
if (checksumTotal % 103 != lastCode)
{
return null;
}
// Need to pull out the check digits from string
int resultLength = result.Length;
if (resultLength == 0)
{
// false positive
return null;
}
// 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, 2);
}
else
{
result.Remove(resultLength - 1, 1);
}
}
float left = (startPatternInfo[1] + startPatternInfo[0]) / 2.0f;
float right = (nextStart + lastStart) / 2.0f;
var resultPointCallback = hints == null || !hints.ContainsKey(DecodeHintType.NEED_RESULT_POINT_CALLBACK)
? null
: (ResultPointCallback)hints[DecodeHintType.NEED_RESULT_POINT_CALLBACK];
if (resultPointCallback != null)
{
resultPointCallback(new ResultPoint(left, rowNumber));
resultPointCallback(new ResultPoint(right, rowNumber));
}
int rawCodesSize = rawCodes.Count;
var rawBytes = new byte[rawCodesSize];
for (int i = 0; i < rawCodesSize; i++)
{
rawBytes[i] = rawCodes[i];
}
return new Result(
result.ToString(),
rawBytes,
new []
{
new ResultPoint(left, rowNumber),
new ResultPoint(right, rowNumber)
},
BarcodeFormat.CODE_128);
}
/// <summary>
/// </summary>
/// <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/...</param>
/// pixel counts, otherwise, it is interpreted as black/white/black/...
/// <param name="pattern">pattern of counts of number of black and white pixels that are being</param>
/// searched for as a pattern
/// <param name="counters">array of counters, as long as pattern, to re-use</param>
/// <returns>start/end horizontal offset of guard pattern, as an array of two ints</returns>
internal static int[] findGuardPattern(BitArray row,
int rowOffset,
bool whiteFirst,
int[] pattern,
int[] counters)
{
int patternLength = pattern.Length;
int width = row.Size;
bool isWhite = whiteFirst;
rowOffset = whiteFirst ? row.getNextUnset(rowOffset) : row.getNextSet(rowOffset);
int counterPosition = 0;
int patternStart = rowOffset;
for (int x = rowOffset; x < width; x++)
{
if (row[x] ^ 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];
Array.Copy(counters, 2, counters, 0, patternLength - 2);
counters[patternLength - 2] = 0;
counters[patternLength - 1] = 0;
counterPosition--;
}
else
{
counterPosition++;
}
counters[counterPosition] = 1;
isWhite = !isWhite;
}
}
return null;
}
/// <summary>
/// Records the size of all runs of white and black pixels, starting with white.
/// This is just like recordPattern, except it records all the counters, and
/// uses our builtin "counters" member for storage.
/// </summary>
/// <param name="row">row to count from</param>
private bool setCounters(BitArray row)
{
counterLength = 0;
// Start from the first white bit.
int i = row.getNextUnset(0);
int end = row.Size;
if (i >= end)
{
return false;
}
bool isWhite = true;
int count = 0;
while (i < end)
{
if (row[i] ^ isWhite)
{
// that is, exactly one is true
count++;
}
else
{
counterAppend(count);
count = 1;
isWhite = !isWhite;
}
i++;
}
counterAppend(count);
return true;
}
private FinderPattern parseFoundFinderPattern(BitArray row, int rowNumber, bool oddPattern)
{
// Actually we found elements 2-5.
int firstCounter;
int start;
int end;
if (oddPattern)
{
// If pattern number is odd, we need to locate element 1 *before* the current block.
int firstElementStart = startEnd[0] - 1;
// Locate element 1
while (firstElementStart >= 0 && !row[firstElementStart])
{
firstElementStart--;
}
firstElementStart++;
firstCounter = startEnd[0] - firstElementStart;
start = firstElementStart;
end = startEnd[1];
}
else
{
// If pattern number is even, the pattern is reversed, so we need to locate element 1 *after* the current block.
start = startEnd[0];
end = row.getNextUnset(startEnd[1] + 1);
firstCounter = end - startEnd[1];
}
// Make 'counters' hold 1-4
int[] counters = getDecodeFinderCounters();
Array.Copy(counters, 0, counters, 1, counters.Length - 1);
counters[0] = firstCounter;
int value;
if (!parseFinderValue(counters, FINDER_PATTERNS, out value))
return null;
return new FinderPattern(value, new int[] { start, end }, start, end, rowNumber);
}
private static int getNextSecondBar(BitArray row, int initialPos)
{
int currentPos;
if (row[initialPos])
{
currentPos = row.getNextUnset(initialPos);
currentPos = row.getNextSet(currentPos);
}
else
{
currentPos = row.getNextSet(initialPos);
currentPos = row.getNextUnset(currentPos);
}
return currentPos;
}
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 checkParity = 0;
for (int x = 0; x < 2 && rowOffset < end; x++)
{
int bestMatch;
if (!UPCEANReader.decodeDigit(row, counters, rowOffset, UPCEANReader.L_AND_G_PATTERNS, out bestMatch))
return -1;
resultString.Append((char)('0' + bestMatch % 10));
foreach (int counter in counters)
{
rowOffset += counter;
}
if (bestMatch >= 10)
{
checkParity |= 1 << (1 - x);
}
if (x != 1)
{
// Read off separator if not last
rowOffset = row.getNextSet(rowOffset);
rowOffset = row.getNextUnset(rowOffset);
}
}
if (resultString.Length != 2)
{
return -1;
}
if (int.Parse(resultString.ToString()) % 4 != checkParity)
{
return -1;
}
return rowOffset;
}
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 < 5 && rowOffset < end; x++)
{
int bestMatch;
if (!UPCEANReader.decodeDigit(row, counters, rowOffset, UPCEANReader.L_AND_G_PATTERNS, out bestMatch))
return -1;
resultString.Append((char)('0' + bestMatch % 10));
foreach (int counter in counters)
{
rowOffset += counter;
}
if (bestMatch >= 10)
{
lgPatternFound |= 1 << (4 - x);
}
if (x != 4)
{
// Read off separator if not last
rowOffset = row.getNextSet(rowOffset);
rowOffset = row.getNextUnset(rowOffset);
}
}
if (resultString.Length != 5)
{
return -1;
}
int checkDigit;
if (!determineCheckDigit(lgPatternFound, out checkDigit))
return -1;
if (extensionChecksum(resultString.ToString()) != checkDigit)
{
return -1;
}
return rowOffset;
}
