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; }
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> <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); }