/** * Decodes a Data Matrix Code represented as a {@link BitMatrix}. A 1 or "true" is taken to mean a * black module. * * @param bits booleans representing white/black Data Matrix Code modules * @return text and bytes encoded within the Data Matrix Code * @throws FormatException if the Data Matrix Code cannot be decoded * @throws ChecksumException if error correction fails */ public DecoderResult decode(BitMatrix bits) throws FormatException, ChecksumException { // Construct a parser and read version, error-correction level BitMatrixParser parser = new BitMatrixParser(bits); Version version = parser.getVersion(); // Read codewords byte[] codewords = parser.readCodewords(); // Separate into data blocks DataBlock[] dataBlocks = DataBlock.getDataBlocks(codewords, version); // Count total number of data bytes int totalBytes = 0; for (int i = 0; i < dataBlocks.length; i++) { totalBytes += dataBlocks[i].getNumDataCodewords(); } byte[] resultBytes = new byte[totalBytes]; int resultOffset = 0; // Error-correct and copy data blocks together into a stream of bytes for (int j = 0; j < dataBlocks.length; j++) { DataBlock dataBlock = dataBlocks[j]; byte[] codewordBytes = dataBlock.getCodewords(); int numDataCodewords = dataBlock.getNumDataCodewords(); correctErrors(codewordBytes, numDataCodewords); for (int i = 0; i < numDataCodewords; i++) { resultBytes[resultOffset++] = codewordBytes[i]; } } // Decode the contents of that stream of bytes return DecodedBitStreamParser.decode(resultBytes); }