// 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, version, maskPattern, matrix); // Data should be embedded at end. embedDataBits(dataBits, maskPattern, matrix); }
/// <summary> /// /// </summary> /// <param name="content"></param> /// <param name="ecLevel"></param> /// <param name="hints"></param> /// <param name="qrCode"></param> public static void encode(System.String content, ErrorCorrectionLevel ecLevel, System.Collections.Hashtable hints, MicroQRCode qrCode, int versionNum) { if (versionNum < 1 || versionNum > 4) throw new ArgumentOutOfRangeException("versionNum", "versionNum [1, 4]"); System.String encoding = hints == null ? null : (System.String)hints[EncodeHintType.CHARACTER_SET]; 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, versionNum); // Step 3: Initialize QR code that can contain "dataBits". int numInputBytes = dataBits.sizeInBytes(); initQRCode(numInputBytes, ecLevel, mode, qrCode, versionNum); // Step 4: Build another bit vector that contains header and data. BitVector headerAndDataBits = new BitVector(); //INFO ECB+Mode+Length+Data[+terminate] // Step 4.5: Append ECI message if applicable appendModeInfo(mode, headerAndDataBits, versionNum); 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, versionNum); // Step 6: Interleave data bits with error correction code. BitVector finalBits = new BitVector(); interleaveWithECBytes(headerAndDataBits, versionNum, 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; //var decoder = new com.google.zxing.microqrcode.decoder.Decoder(); //var res = decoder.decode(com.google.zxing.common.BitMatrix.FromByteMatrix(matrix)); //Console.WriteLine(res.Text); // Step 9. Make sure we have a valid QR Code. if (!qrCode.Valid) { throw new WriterException("Invalid QR code: " + qrCode.ToString()); } }
private static int chooseMaskPattern(BitVector bits, ErrorCorrectionLevel ecLevel, int version, ByteMatrix matrix) { int maxPenalty = System.Int32.MinValue; // highest penalty is better. int bestMaskPattern = -1; // We try all mask patterns to choose the best one. for (int maskPattern = 0; maskPattern < MicroQRCode.NUM_MASK_PATTERNS; maskPattern++) { MatrixUtil.buildMatrix(bits, ecLevel, version, maskPattern, matrix); int penalty = calculateMaskPenalty(matrix); if (penalty > maxPenalty) { maxPenalty = penalty; bestMaskPattern = maskPattern; } } return bestMaskPattern; }
/// <summary> Terminate bits as described in 8.4.8 and 8.4.9 of JISX0510:2004 (p.24).</summary> internal static void terminateBits(int numDataBytes, BitVector bits, int versionNum) { int capacity = numDataBytes << 3; //ISO/IEC 18004:2006(E) 6.4.10 Bit stream to codeword conversion //All codewords are 8 bits in length, except for the final data symbol character in Micro //QR Code versions M1 and M3 symbols, which is 4 bits in length int bitLen = (versionNum == 1 || versionNum == 3) ? 4 : 8; if (bitLen == 4) capacity -= 4; if (bits.size() > capacity) { throw new WriterException("data bits cannot fit in the QR Code" + bits.size() + " > " + capacity); } // Append termination bits. See 8.4.8 of JISX0510:2004 (p.24) for details. // TODO: srowen says we can remove this for loop, since the 4 terminator bits are optional if // the last byte has less than 4 bits left. So it amounts to padding the last byte with zeroes // either way. var terminatorMode = Mode.TERMINATOR; var ctLen = terminatorMode.getBitsLength(versionNum); for (int i = 0; i < ctLen && bits.size() < capacity; ++i) { bits.appendBit(0); } int numBitsInLastByte = bits.size() % bitLen; // If the last byte isn't 8-bit aligned, we'll add padding bits. if (numBitsInLastByte > 0) { int numPaddingBits = bitLen - numBitsInLastByte; for (int i = 0; i < numPaddingBits; ++i) { bits.appendBit(0); } } // Should be 8-bit aligned here. if (bits.size() % bitLen != 0) { throw new WriterException("Number of bits is not a multiple of 8"); } //ISO/IEC 18004:2006(E) 6.4.10 Bit stream to codeword conversion //The message bit stream shall then be //extended to fill the data capacity of the symbol corresponding to the Version and Error Correction Level, as //defined in Table 8, by adding the Pad Codewords 11101100 and 00010001 alternately. // If we have more space, we'll fill the space with padding patterns defined in 8.4.9 (p.24). int numPaddingBytes = numDataBytes - bits.sizeInBytes(); while (numPaddingBytes * 8 > (capacity - bits.size()) && numPaddingBytes > 0) numPaddingBytes--; for (int i = 0; i < numPaddingBytes; ++i) { if (i % 2 == 0) { bits.appendBits(0xec, 8); //11101100 } else { bits.appendBits(0x11, 8);//00010001 } } //For Micro QR Code versions M1 and M3 symbols, the final data codeword is 4 bits long. The Pad Codeword used in the final data //symbol character position in Micro QR Code versions M1 and M3 symbols shall be represented as 0000. if (bitLen == 4 && bits.size() < capacity) bits.appendBits(0x0, 4);//0000 if (bits.size() != capacity) { throw new WriterException("Bits size does not equal capacity"); } }
/// <summary> Interleave "bits" with corresponding error correction bytes. On success, store the result in /// "result". The interleave rule is complicated. See 8.6 of JISX0510:2004 (p.37) for details. /// </summary> internal static void interleaveWithECBytes(BitVector bits, int versionNum, int numTotalBytes, int numDataBytes, int numRSBlocks, BitVector result) { // "bits" must have "getNumDataBytes" bytes of data. if (bits.sizeInBytes() != numDataBytes) { throw new WriterException("Number of bits and data bytes does not match"); } // Step 1. Divide data bytes into blocks and generate error correction bytes for them. We'll // store the divided data bytes blocks and error correction bytes blocks into "blocks". int dataBytesOffset = 0; int maxNumDataBytes = 0; int maxNumEcBytes = 0; // Since, we know the number of reedsolmon blocks, we can initialize the vector with the number. System.Collections.ArrayList blocks = System.Collections.ArrayList.Synchronized(new System.Collections.ArrayList(numRSBlocks)); for (int i = 0; i < numRSBlocks; ++i) { int[] numDataBytesInBlock = new int[1]; int[] numEcBytesInBlock = new int[1]; getNumDataBytesAndNumECBytesForBlockID(numTotalBytes, numDataBytes, numRSBlocks, i, numDataBytesInBlock, numEcBytesInBlock); ByteArray dataBytes = new ByteArray(); dataBytes.set_Renamed(bits.Array, dataBytesOffset, numDataBytesInBlock[0]); ByteArray ecBytes = generateECBytes(dataBytes, numEcBytesInBlock[0]); blocks.Add(new BlockPair(dataBytes, ecBytes)); maxNumDataBytes = System.Math.Max(maxNumDataBytes, dataBytes.size()); maxNumEcBytes = System.Math.Max(maxNumEcBytes, ecBytes.size()); dataBytesOffset += numDataBytesInBlock[0]; } if (numDataBytes != dataBytesOffset) { throw new WriterException("Data bytes does not match offset"); } // First, place data blocks. var bitLen = bits.size(); for (int i = 0; i < maxNumDataBytes; ++i) { for (int j = 0; j < blocks.Count; ++j) { ByteArray dataBytes = ((BlockPair)blocks[j]).DataBytes; if (i < dataBytes.size()) { if (bitLen == 4) result.appendBits(dataBytes.at(i) >> 4, 4); else result.appendBits(dataBytes.at(i), 8); } } bitLen -= 8; } // Then, place error correction blocks. for (int i = 0; i < maxNumEcBytes; ++i) { for (int j = 0; j < blocks.Count; ++j) { ByteArray ecBytes = ((BlockPair)blocks[j]).ErrorCorrectionBytes; if (i < ecBytes.size()) { result.appendBits(ecBytes.at(i), 8); } } } if (numTotalBytes != result.sizeInBytes()) { // Should be same. throw new WriterException("Interleaving error: " + numTotalBytes + " and " + result.sizeInBytes() + " differ."); } }
/// <summary> /// /// </summary> /// <param name="content"></param> /// <param name="bits"></param> internal static void appendNumericBytes(System.String content, BitVector bits) { int length = content.Length; int i = 0; while (i < length) { int num1 = content[i] - '0'; if (i + 2 < length) { // Encode three numeric letters in ten bits. int num2 = content[i + 1] - '0'; int num3 = content[i + 2] - '0'; bits.appendBits(num1 * 100 + num2 * 10 + num3, 10); i += 3; } else if (i + 1 < length) { // Encode two numeric letters in seven bits. int num2 = content[i + 1] - '0'; bits.appendBits(num1 * 10 + num2, 7); i += 2; } else { // Encode one numeric letter in four bits. bits.appendBits(num1, 4); i++; } } }
/// <summary> Append mode info. On success, store the result in "bits".</summary> internal static void appendModeInfo(Mode mode, BitVector bits, int versionNum) { bits.appendBits(mode.Bits, mode.getBitsLength(versionNum)); }
/// <summary> Append length info. On success, store the result in "bits".</summary> internal static void appendLengthInfo(int numLetters, int version, Mode mode, BitVector bits) { int numBits = mode.getCharacterCountBits(Version.getVersionForNumber(version)); if (numLetters > ((1 << numBits) - 1)) { throw new WriterException(numLetters + "is bigger than" + ((1 << numBits) - 1)); } bits.appendBits(numLetters, numBits); }
/// <summary> /// /// </summary> /// <param name="content"></param> /// <param name="bits"></param> internal static void appendKanjiBytes(System.String content, BitVector bits) { sbyte[] bytes; try { //UPGRADE_TODO: Method 'java.lang.String.getBytes' was converted to 'System.Text.Encoding.GetEncoding(string).GetBytes(string)' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javalangStringgetBytes_javalangString'" bytes = SupportClass.ToSByteArray(System.Text.Encoding.GetEncoding("Shift_JIS").GetBytes(content)); } catch (System.IO.IOException uee) { //UPGRADE_TODO: The equivalent in .NET for method 'java.lang.Throwable.toString' may return a different value. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1043'" throw new WriterException(uee.ToString()); } int length = bytes.Length; for (int i = 0; i < length; i += 2) { int byte1 = bytes[i] & 0xFF; int byte2 = bytes[i + 1] & 0xFF; int code = (byte1 << 8) | byte2; int subtracted = -1; if (code >= 0x8140 && code <= 0x9ffc) { subtracted = code - 0x8140; } else if (code >= 0xe040 && code <= 0xebbf) { subtracted = code - 0xc140; } if (subtracted == -1) { throw new WriterException("Invalid byte sequence"); } int encoded = ((subtracted >> 8) * 0xc0) + (subtracted & 0xff); bits.appendBits(encoded, 13); } }
/// <summary> Append "bytes" in "mode" mode (encoding) into "bits". On success, store the result in "bits".</summary> internal static void appendBytes(System.String content, Mode mode, BitVector bits, System.String encoding, int versionNum) { if (mode.Equals(Mode.NUMERIC)) { appendNumericBytes(content, bits); } else if (mode.Equals(Mode.ALPHANUMERIC) && versionNum >= 2) { appendAlphanumericBytes(content, bits); } else if (mode.Equals(Mode.BYTE) && versionNum >= 3) { append8BitBytes(content, bits, encoding); } else if (mode.Equals(Mode.KANJI) && versionNum >= 3) { appendKanjiBytes(content, bits); } else { throw new WriterException("Invalid mode: " + mode); } }
/// <summary> /// /// </summary> /// <param name="content"></param> /// <param name="bits"></param> internal static void appendAlphanumericBytes(System.String content, BitVector bits) { int length = content.Length; int i = 0; while (i < length) { int code1 = getAlphanumericCode(content[i]); if (code1 == -1) { throw new WriterException(); } if (i + 1 < length) { int code2 = getAlphanumericCode(content[i + 1]); if (code2 == -1) { throw new WriterException(); } // Encode two alphanumeric letters in 11 bits. bits.appendBits(code1 * 45 + code2, 11); i += 2; } else { // Encode one alphanumeric letter in six bits. bits.appendBits(code1, 6); i++; } } }
/// <summary> /// /// </summary> /// <param name="content"></param> /// <param name="bits"></param> /// <param name="encoding"></param> internal static void append8BitBytes(System.String content, BitVector bits, System.String encoding) { sbyte[] bytes; try { //UPGRADE_TODO: Method 'java.lang.String.getBytes' was converted to 'System.Text.Encoding.GetEncoding(string).GetBytes(string)' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javalangStringgetBytes_javalangString'" bytes = SupportClass.ToSByteArray(System.Text.Encoding.GetEncoding(encoding).GetBytes(content)); } catch (System.IO.IOException uee) { //UPGRADE_TODO: The equivalent in .NET for method 'java.lang.Throwable.toString' may return a different value. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1043'" throw new WriterException(uee.ToString()); } for (int i = 0; i < bytes.Length; ++i) { bits.appendBits(bytes[i], 8); } }
/// <summary> /// 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. /// </summary> /// <param name="ecLevel"></param> /// <param name="maskPattern"></param> /// <param name="bits"></param> /// <remarks> /// ISO/IEC 18004:2006(E) 6.9 Format information /// </remarks> public static void makeTypeInfoBits(ErrorCorrectionLevel ecLevel, int version, int maskPattern, BitVector bits) { if (!MicroQRCode.isValidMaskPattern(maskPattern)) { throw new WriterException("Invalid mask pattern"); } //ISO/IEC 18004:2006(E) 6.9 Format information //Symbol number 0: 000 //Data mask pattern reference: 11 //Data bits (symbol number, data mask pattern reference): 00011 //BCH bits: 1101011001 //Unmasked bit sequence: 000111101011001 //Mask pattern for XOR operation: 100010001000101 //Format information module pattern: 100101100011100 int typeInfo = SYMBOL_NUMBERS_INFO[version - 1][ecLevel.ordinal()]; if (typeInfo == -1) { throw new WriterException("Invalid Version&Level info"); } typeInfo = (typeInfo << 2) | 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()); } }
/// <summary> /// 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. /// </summary> /// <param name="ecLevel"></param> /// <param name="maskPattern"></param> /// <param name="bits"></param> /// <remarks> /// ISO/IEC 18004:2006(E) 6.9 Format information /// </remarks> public static void makeTypeInfoBits(ErrorCorrectionLevel ecLevel, int version, int maskPattern, BitVector bits) { if (!MicroQRCode.isValidMaskPattern(maskPattern)) { throw new WriterException("Invalid mask pattern"); } //ISO/IEC 18004:2006(E) 6.9 Format information //Symbol number 0: 000 //Data mask pattern reference: 11 //Data bits (symbol number, data mask pattern reference): 00011 //BCH bits: 1101011001 //Unmasked bit sequence: 000111101011001 //Mask pattern for XOR operation: 100010001000101 //Format information module pattern: 100101100011100 int typeInfo = SYMBOL_NUMBERS_INFO[version - 1][ecLevel.ordinal()]; if (typeInfo == -1) throw new WriterException("Invalid Version&Level info"); typeInfo = (typeInfo << 2) | 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 version, int maskPattern, ByteMatrix matrix) { BitVector typeInfoBits = new BitVector(); makeTypeInfoBits(ecLevel, version, 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); } }
// Embed "dataBits" using "getMaskPattern". On success, modify the matrix and return true. // For debugging purposes, it skips masking process if "getMaskPattern" is -1. // See 8.7 of JISX0510:2004 (p.38) for how to embed data bits. public static void embedDataBits(BitVector dataBits, int maskPattern, ByteMatrix matrix) { int bitIndex = 0; int direction = -1; // Start from the right bottom cell. int x = matrix.Width - 1; int y = matrix.Height - 1; while (x > 0) { while (y >= 0 && y < matrix.Height) { for (int i = 0; i < 2; ++i) { int xx = x - i; // Skip the cell if it's not empty. if (!isEmpty(matrix.get_Renamed(xx, y))) { continue; } int bit; if (bitIndex < dataBits.size()) { bit = dataBits.at(bitIndex); ++bitIndex; } else { // Padding bit. If there is no bit left, we'll fill the left cells with 0, as described // in 8.4.9 of JISX0510:2004 (p. 24). bit = 0; } // Skip masking if mask_pattern is -1. if (maskPattern != -1) { if (MaskUtil.getDataMaskBit(maskPattern, xx, y)) { bit ^= 0x1; } } matrix.set_Renamed(xx, y, bit); } y += direction; } direction = -direction; // Reverse the direction. y += direction; x -= 2; // Move to the left. } // All bits should be consumed. if (bitIndex != dataBits.size()) { throw new WriterException("Not all bits consumed: " + bitIndex + '/' + dataBits.size()); } }