public DecoderResult(sbyte[] rawBytes, System.String text, System.Collections.Generic.List<Object> byteSegments, ErrorCorrectionLevel ecLevel) { if (rawBytes == null && text == null) { throw new System.ArgumentException(); } this.rawBytes = rawBytes; this.text = text; this.byteSegments = byteSegments; this.ecLevel = ecLevel; }
// Build 2D matrix of QR Code from "dataBits" with "ecLevel", "version" and "getMaskPattern". On // success, store the result in "matrix" and return true. public static void buildMatrix(BitVector dataBits, ErrorCorrectionLevel ecLevel, int version, int maskPattern, ByteMatrix matrix) { clearMatrix(matrix); embedBasicPatterns(version, matrix); // Type information appear with any version. embedTypeInfo(ecLevel, maskPattern, matrix); // Version info appear if version >= 7. maybeEmbedVersionInfo(version, matrix); // Data should be embedded at end. embedDataBits(dataBits, maskPattern, matrix); }
/// <summary> Initialize "qrCode" according to "numInputBytes", "ecLevel", and "mode". On success, /// modify "qrCode". /// </summary> private static void initQRCode(int numInputBytes, ErrorCorrectionLevel ecLevel, Mode mode, QRCode qrCode) { qrCode.ECLevel = ecLevel; qrCode.Mode = mode; // In the following comments, we use numbers of Version 7-H. for (int versionNum = 1; versionNum <= 40; versionNum++) { Version version = Version.getVersionForNumber(versionNum); // numBytes = 196 int numBytes = version.TotalCodewords; // getNumECBytes = 130 Version.ECBlocks ecBlocks = version.getECBlocksForLevel(ecLevel); int numEcBytes = ecBlocks.TotalECCodewords; // getNumRSBlocks = 5 int numRSBlocks = ecBlocks.NumBlocks; // getNumDataBytes = 196 - 130 = 66 int numDataBytes = numBytes - numEcBytes; // We want to choose the smallest version which can contain data of "numInputBytes" + some // extra bits for the header (mode info and length info). The header can be three bytes // (precisely 4 + 16 bits) at most. Hence we do +3 here. if (numDataBytes >= numInputBytes + 3) { // Yay, we found the proper rs block info! qrCode.Version = versionNum; qrCode.NumTotalBytes = numBytes; qrCode.NumDataBytes = numDataBytes; qrCode.NumRSBlocks = numRSBlocks; // getNumECBytes = 196 - 66 = 130 qrCode.NumECBytes = numEcBytes; // matrix width = 21 + 6 * 4 = 45 qrCode.MatrixWidth = version.DimensionForVersion; return ; } } throw new WriterException("Cannot find proper rs block info (input data too big?)"); }
private static int chooseMaskPattern(BitVector bits, ErrorCorrectionLevel ecLevel, int version, ByteMatrix matrix) { int minPenalty = System.Int32.MaxValue; // Lower penalty is better. int bestMaskPattern = - 1; // We try all mask patterns to choose the best one. for (int maskPattern = 0; maskPattern < QRCode.NUM_MASK_PATTERNS; maskPattern++) { MatrixUtil.buildMatrix(bits, ecLevel, version, maskPattern, matrix); int penalty = calculateMaskPenalty(matrix); if (penalty < minPenalty) { minPenalty = penalty; bestMaskPattern = maskPattern; } } return bestMaskPattern; }
public static void encode(System.String content, ErrorCorrectionLevel ecLevel, System.Collections.Generic.Dictionary<Object,Object> hints, QRCode qrCode) { System.String encoding = (hints != null && hints.ContainsKey(EncodeHintType.CHARACTER_SET))?(System.String) hints[EncodeHintType.CHARACTER_SET]:null; if (encoding == null) { encoding = DEFAULT_BYTE_MODE_ENCODING; } // Step 1: Choose the mode (encoding). Mode mode = chooseMode(content, encoding); // Step 2: Append "bytes" into "dataBits" in appropriate encoding. BitVector dataBits = new BitVector(); appendBytes(content, mode, dataBits, encoding); // Step 3: Initialize QR code that can contain "dataBits". int numInputBytes = dataBits.sizeInBytes(); initQRCode(numInputBytes, ecLevel, mode, qrCode); // Step 4: Build another bit vector that contains header and data. BitVector headerAndDataBits = new BitVector(); // Step 4.5: Append ECI message if applicable if (mode == Mode.BYTE && !DEFAULT_BYTE_MODE_ENCODING.Equals(encoding)) { CharacterSetECI eci = CharacterSetECI.getCharacterSetECIByName(encoding); if (eci != null) { appendECI(eci, headerAndDataBits); } } appendModeInfo(mode, headerAndDataBits); int numLetters = mode.Equals(Mode.BYTE)?dataBits.sizeInBytes():content.Length; appendLengthInfo(numLetters, qrCode.Version, mode, headerAndDataBits); headerAndDataBits.appendBitVector(dataBits); // Step 5: Terminate the bits properly. terminateBits(qrCode.NumDataBytes, headerAndDataBits); // Step 6: Interleave data bits with error correction code. BitVector finalBits = new BitVector(); interleaveWithECBytes(headerAndDataBits, qrCode.NumTotalBytes, qrCode.NumDataBytes, qrCode.NumRSBlocks, finalBits); // Step 7: Choose the mask pattern and set to "qrCode". ByteMatrix matrix = new ByteMatrix(qrCode.MatrixWidth, qrCode.MatrixWidth); qrCode.MaskPattern = chooseMaskPattern(finalBits, qrCode.ECLevel, qrCode.Version, matrix); // Step 8. Build the matrix and set it to "qrCode". MatrixUtil.buildMatrix(finalBits, qrCode.ECLevel, qrCode.Version, qrCode.MaskPattern, matrix); qrCode.Matrix = matrix; // Step 9. Make sure we have a valid QR Code. if (!qrCode.Valid) { throw new WriterException("Invalid QR code: " + qrCode.ToString()); } }
/// <summary> Encode "bytes" with the error correction level "ecLevel". The encoding mode will be chosen /// internally by chooseMode(). On success, store the result in "qrCode". /// /// We recommend you to use QRCode.EC_LEVEL_L (the lowest level) for /// "getECLevel" since our primary use is to show QR code on desktop screens. We don't need very /// strong error correction for this purpose. /// /// Note that there is no way to encode bytes in MODE_KANJI. We might want to add EncodeWithMode() /// with which clients can specify the encoding mode. For now, we don't need the functionality. /// </summary> public static void encode(System.String content, ErrorCorrectionLevel ecLevel, QRCode qrCode) { encode(content, ecLevel, null, qrCode); }
// Make bit vector of type information. On success, store the result in "bits" and return true. // Encode error correction level and mask pattern. See 8.9 of // JISX0510:2004 (p.45) for details. public static void makeTypeInfoBits(ErrorCorrectionLevel ecLevel, int maskPattern, BitVector bits) { if (!QRCode.isValidMaskPattern(maskPattern)) { throw new WriterException("Invalid mask pattern"); } int typeInfo = (ecLevel.Bits << 3) | maskPattern; bits.appendBits(typeInfo, 5); int bchCode = calculateBCHCode(typeInfo, TYPE_INFO_POLY); bits.appendBits(bchCode, 10); BitVector maskBits = new BitVector(); maskBits.appendBits(TYPE_INFO_MASK_PATTERN, 15); bits.xor(maskBits); if (bits.size() != 15) { // Just in case. throw new WriterException("should not happen but we got: " + bits.size()); } }
// Embed type information. On success, modify the matrix. public static void embedTypeInfo(ErrorCorrectionLevel ecLevel, int maskPattern, ByteMatrix matrix) { BitVector typeInfoBits = new BitVector(); makeTypeInfoBits(ecLevel, maskPattern, typeInfoBits); for (int i = 0; i < typeInfoBits.size(); ++i) { // Place bits in LSB to MSB order. LSB (least significant bit) is the last value in // "typeInfoBits". int bit = typeInfoBits.at(typeInfoBits.size() - 1 - i); // Type info bits at the left top corner. See 8.9 of JISX0510:2004 (p.46). int x1 = TYPE_INFO_COORDINATES[i][0]; int y1 = TYPE_INFO_COORDINATES[i][1]; matrix.set_Renamed(x1, y1, bit); if (i < 8) { // Right top corner. int x2 = matrix.Width - i - 1; int y2 = 8; matrix.set_Renamed(x2, y2, bit); } else { // Left bottom corner. int x2 = 8; int y2 = matrix.Height - 7 + (i - 8); matrix.set_Renamed(x2, y2, bit); } } }
internal static DecoderResult decode(sbyte[] bytes, Version version, ErrorCorrectionLevel ecLevel) { BitSource bits = new BitSource(bytes); System.Text.StringBuilder result = new System.Text.StringBuilder(50); CharacterSetECI currentCharacterSetECI = null; bool fc1InEffect = false; System.Collections.Generic.List<Object> byteSegments = new System.Collections.Generic.List<Object>(1); Mode mode; do { // While still another segment to read... if (bits.available() < 4) { // OK, assume we're done. Really, a TERMINATOR mode should have been recorded here mode = Mode.TERMINATOR; } else { try { mode = Mode.forBits(bits.readBits(4)); // mode is encoded by 4 bits } catch (System.ArgumentException iae) { throw ReaderException.Instance; } } if (!mode.Equals(Mode.TERMINATOR)) { if (mode.Equals(Mode.FNC1_FIRST_POSITION) || mode.Equals(Mode.FNC1_SECOND_POSITION)) { // We do little with FNC1 except alter the parsed result a bit according to the spec fc1InEffect = true; } else if (mode.Equals(Mode.STRUCTURED_APPEND)) { // not really supported; all we do is ignore it // Read next 8 bits (symbol sequence #) and 8 bits (parity data), then continue bits.readBits(16); } else if (mode.Equals(Mode.ECI)) { // Count doesn't apply to ECI int value_Renamed = parseECIValue(bits); currentCharacterSetECI = CharacterSetECI.getCharacterSetECIByValue(value_Renamed); if (currentCharacterSetECI == null) { throw ReaderException.Instance; } } else { // How many characters will follow, encoded in this mode? int count = bits.readBits(mode.getCharacterCountBits(version)); if (mode.Equals(Mode.NUMERIC)) { decodeNumericSegment(bits, result, count); } else if (mode.Equals(Mode.ALPHANUMERIC)) { decodeAlphanumericSegment(bits, result, count, fc1InEffect); } else if (mode.Equals(Mode.BYTE)) { decodeByteSegment(bits, result, count, currentCharacterSetECI, byteSegments); } else if (mode.Equals(Mode.KANJI)) { decodeKanjiSegment(bits, result, count); } else { throw ReaderException.Instance; } } } } while (!mode.Equals(Mode.TERMINATOR)); return new DecoderResult(bytes, result.ToString(), (byteSegments.Count == 0)?null:byteSegments, ecLevel); }