// Embed position detection patterns and surrounding vertical/horizontal separators. private static void embedPositionDetectionPatternsAndSeparators(ByteMatrix matrix) { // Embed three big squares at corners. int pdpWidth = POSITION_DETECTION_PATTERN[0].Length; // Left top corner. embedPositionDetectionPattern(0, 0, matrix); // Right top corner. embedPositionDetectionPattern(matrix.width() - pdpWidth, 0, matrix); // Left bottom corner. embedPositionDetectionPattern(0, matrix.width() - pdpWidth, matrix); // Embed horizontal separation patterns around the squares. int hspWidth = HORIZONTAL_SEPARATION_PATTERN[0].Length; // Left top corner. embedHorizontalSeparationPattern(0, hspWidth - 1, matrix); // Right top corner. embedHorizontalSeparationPattern(matrix.width() - hspWidth, hspWidth - 1, matrix); // Left bottom corner. embedHorizontalSeparationPattern(0, matrix.width() - hspWidth, matrix); // Embed vertical separation patterns around the squares. int vspSize = VERTICAL_SEPARATION_PATTERN.Length; // Left top corner. embedVerticalSeparationPattern(vspSize, 0, matrix); // Right top corner. embedVerticalSeparationPattern(matrix.height() - vspSize - 1, 0, matrix); // Left bottom corner. embedVerticalSeparationPattern(vspSize, matrix.height() - vspSize, matrix); }
// Helper function for applyMaskPenaltyRule1. We need this for doing this calculation in both // vertical and horizontal orders respectively. private static int applyMaskPenaltyRule1Internal(ByteMatrix matrix, bool isHorizontal) { int penalty = 0; int numSameBitCells = 0; int prevBit = -1; // Horizontal mode: // for (int i = 0; i < matrix.height(); ++i) { // for (int j = 0; j < matrix.width(); ++j) { // int bit = matrix.get(i, j); // Vertical mode: // for (int i = 0; i < matrix.width(); ++i) { // for (int j = 0; j < matrix.height(); ++j) { // int bit = matrix.get(j, i); int iLimit = isHorizontal ? matrix.height() : matrix.width(); int jLimit = isHorizontal ? matrix.width() : matrix.height(); sbyte[][] array = matrix.getArray(); for (int i = 0; i < iLimit; ++i) { for (int j = 0; j < jLimit; ++j) { int bit = isHorizontal ? array[i][j] : array[j][i]; if (bit == prevBit) { numSameBitCells += 1; // Found five repetitive cells with the same color (bit). // We'll give penalty of 3. if (numSameBitCells == 5) { penalty += 3; } else if (numSameBitCells > 5) { // After five repetitive cells, we'll add the penalty one // by one. penalty += 1; } } else { numSameBitCells = 1; // Include the cell itself. prevBit = bit; } } numSameBitCells = 0; // Clear at each row/column. } return(penalty); }
private static void embedTimingPatterns(ByteMatrix matrix) { // -8 is for skipping position detection patterns (size 7), and two horizontal/vertical // separation patterns (size 1). Thus, 8 = 7 + 1. for (int i = 8; i < matrix.width() - 8; ++i) { int bit = (i + 1) % 2; // Horizontal line. if (!isValidValue(matrix.get(6, i))) { throw new WriterException(); } if (isEmpty(matrix.get(6, i))) { matrix.set(6, i, bit); } // Vertical line. if (!isValidValue(matrix.get(i, 6))) { throw new WriterException(); } if (isEmpty(matrix.get(i, 6))) { matrix.set(i, 6, bit); } } }
// 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(y1, x1, bit); if (i < 8) { // Right top corner. int x2 = matrix.width() - i - 1; int y2 = 8; matrix.set(y2, x2, bit); } else { // Left bottom corner. int x2 = 8; int y2 = matrix.height() - 7 + (i - 8); matrix.set(y2, x2, bit); } } }
// Apply mask penalty rule 3 and return the penalty. Find consecutive cells of 00001011101 or // 10111010000, and give penalty to them. If we find patterns like 000010111010000, we give // penalties twice (i.e. 40 * 2). public static int applyMaskPenaltyRule3(ByteMatrix matrix) { int penalty = 0; sbyte[][] array = matrix.getArray(); int width = matrix.width(); int height = matrix.height(); for (int y = 0; y < height; ++y) { for (int x = 0; x < width; ++x) { // Tried to simplify following conditions but failed. if (x + 6 < width && array[y][x] == 1 && array[y][x + 1] == 0 && array[y][x + 2] == 1 && array[y][x + 3] == 1 && array[y][x + 4] == 1 && array[y][x + 5] == 0 && array[y][x + 6] == 1 && ((x + 10 < width && array[y][x + 7] == 0 && array[y][x + 8] == 0 && array[y][x + 9] == 0 && array[y][x + 10] == 0) || (x - 4 >= 0 && array[y][x - 1] == 0 && array[y][x - 2] == 0 && array[y][x - 3] == 0 && array[y][x - 4] == 0))) { penalty += 40; } if (y + 6 < height && array[y][x] == 1 && array[y + 1][x] == 0 && array[y + 2][x] == 1 && array[y + 3][x] == 1 && array[y + 4][x] == 1 && array[y + 5][x] == 0 && array[y + 6][x] == 1 && ((y + 10 < height && array[y + 7][x] == 0 && array[y + 8][x] == 0 && array[y + 9][x] == 0 && array[y + 10][x] == 0) || (y - 4 >= 0 && array[y - 1][x] == 0 && array[y - 2][x] == 0 && array[y - 3][x] == 0 && array[y - 4][x] == 0))) { penalty += 40; } } } return(penalty); }
// 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) { // Skip the vertical timing pattern. if (x == 6) { x -= 1; } 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(y, xx))) { 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) { int mask = MaskUtil.getDataMaskBit(maskPattern, xx, y); bit ^= mask; } matrix.set(y, xx, 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()); } }
// Checks all the member variables are set properly. Returns true on success. Otherwise, returns // false. public bool isValid() { return // First check if all version are not uninitialized. (mode != null && ecLevel != null && version != -1 && matrixWidth != -1 && maskPattern != -1 && numTotalBytes != -1 && numDataBytes != -1 && numECBytes != -1 && numRSBlocks != -1 && // Then check them in other ways.. isValidMaskPattern(maskPattern) && numTotalBytes == numDataBytes + numECBytes && // ByteMatrix stuff. matrix != null && matrixWidth == matrix.width() && // See 7.3.1 of JISX0510:2004 (p.5). matrix.width() == matrix.height()); // Must be square. }
// Apply mask penalty rule 4 and return the penalty. Calculate the ratio of dark cells and give // penalty if the ratio is far from 50%. It gives 10 penalty for 5% distance. Examples: // - 0% => 100 // - 40% => 20 // - 45% => 10 // - 50% => 0 // - 55% => 10 // - 55% => 20 // - 100% => 100 public static int applyMaskPenaltyRule4(ByteMatrix matrix) { int numDarkCells = 0; sbyte[][] array = matrix.getArray(); int width = matrix.width(); int height = matrix.height(); for (int y = 0; y < height; ++y) { for (int x = 0; x < width; ++x) { if (array[y][x] == 1) { numDarkCells += 1; } } } int numTotalCells = matrix.height() * matrix.width(); double darkRatio = (double)numDarkCells / numTotalCells; return(Math.Abs((int)(darkRatio * 100 - 50)) / 5 * 10); }
// Apply mask penalty rule 2 and return the penalty. Find 2x2 blocks with the same color and give // penalty to them. public static int applyMaskPenaltyRule2(ByteMatrix matrix) { int penalty = 0; sbyte[][] array = matrix.getArray(); int width = matrix.width(); int height = matrix.height(); for (int y = 0; y < height - 1; ++y) { for (int x = 0; x < width - 1; ++x) { int value = array[y][x]; if (value == array[y][x + 1] && value == array[y + 1][x] && value == array[y + 1][x + 1]) { penalty += 3; } } } return(penalty); }
// Note that the input matrix uses 0 == white, 1 == black, while the output matrix uses // 0 == black, 255 == white (i.e. an 8 bit greyscale bitmap). private static ByteMatrix renderResult(QRCode code, int width, int height) { ByteMatrix input = code.getMatrix(); int inputWidth = input.width(); int inputHeight = input.height(); int qrWidth = inputWidth + (QUIET_ZONE_SIZE << 1); int qrHeight = inputHeight + (QUIET_ZONE_SIZE << 1); int outputWidth = Math.Max(width, qrWidth); int outputHeight = Math.Max(height, qrHeight); int multiple = Math.Min(outputWidth / qrWidth, outputHeight / qrHeight); // Padding includes both the quiet zone and the extra white pixels to accomodate the requested // dimensions. For example, if input is 25x25 the QR will be 33x33 including the quiet zone. // If the requested size is 200x160, the multiple will be 4, for a QR of 132x132. These will // handle all the padding from 100x100 (the actual QR) up to 200x160. int leftPadding = (outputWidth - (inputWidth * multiple)) / 2; int topPadding = (outputHeight - (inputHeight * multiple)) / 2; ByteMatrix output = new ByteMatrix(outputHeight, outputWidth); sbyte[][] outputArray = output.getArray(); // We could be tricky and use the first row in each set of multiple as the temporary storage, // instead of allocating this separate array. sbyte[] row = new sbyte[outputWidth]; // 1. Write the white lines at the top for (int y = 0; y < topPadding; y++) { setRowColor(outputArray[y], unchecked ((sbyte)255)); } // 2. Expand the QR image to the multiple sbyte[][] inputArray = input.getArray(); for (int y = 0; y < inputHeight; y++) { // a. Write the white pixels at the left of each row for (int x = 0; x < leftPadding; x++) { row[x] = unchecked ((sbyte)255); } // b. Write the contents of this row of the barcode int offset = leftPadding; for (int x = 0; x < inputWidth; x++) { sbyte value = (inputArray[y][x] == 1) ? (sbyte)0 : unchecked ((sbyte)255); for (int z = 0; z < multiple; z++) { row[offset + z] = value; } offset += multiple; } // c. Write the white pixels at the right of each row offset = leftPadding + (inputWidth * multiple); for (int x = offset; x < outputWidth; x++) { row[x] = unchecked ((sbyte)255); } // d. Write the completed row multiple times offset = topPadding + (y * multiple); for (int z = 0; z < multiple; z++) { System.Array.Copy(row, 0, outputArray[offset + z], 0, outputWidth); } } // 3. Write the white lines at the bottom int offset2 = topPadding + (inputHeight * multiple); for (int y = offset2; y < outputHeight; y++) { setRowColor(outputArray[y], unchecked ((sbyte)255)); } return(output); }