using System.Collections.Generic;
/*
* Copyright 2007 ZXing authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
namespace com.google.zxing.qrcode.decoder
{
using ChecksumException = com.google.zxing.ChecksumException;
using DecodeHintType = com.google.zxing.DecodeHintType;
using FormatException = com.google.zxing.FormatException;
using BitMatrix = com.google.zxing.common.BitMatrix;
using DecoderResult = com.google.zxing.common.DecoderResult;
using GenericGF = com.google.zxing.common.reedsolomon.GenericGF;
using ReedSolomonDecoder = com.google.zxing.common.reedsolomon.ReedSolomonDecoder;
using ReedSolomonException = com.google.zxing.common.reedsolomon.ReedSolomonException;
/// <summary>
/// <p>The main class which implements QR Code decoding -- as opposed to locating and extracting
/// the QR Code from an image.</p>
///
/// @author Sean Owen
/// </summary>
public sealed class Decoder
{
private readonly ReedSolomonDecoder rsDecoder;
public Decoder()
{
rsDecoder = new ReedSolomonDecoder(GenericGF.QR_CODE_FIELD_256);
}
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in .NET:
//ORIGINAL LINE: public com.google.zxing.common.DecoderResult decode(boolean[][] image) throws com.google.zxing.ChecksumException, com.google.zxing.FormatException
public DecoderResult decode(bool[][] image)
{
return decode(image, null);
}
/// <summary>
/// <p>Convenience method that can decode a QR Code represented as a 2D array of booleans.
/// "true" is taken to mean a black module.</p>
/// </summary>
/// <param name="image"> booleans representing white/black QR Code modules </param>
/// <returns> text and bytes encoded within the QR Code </returns>
/// <exception cref="FormatException"> if the QR Code cannot be decoded </exception>
/// <exception cref="ChecksumException"> if error correction fails </exception>
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in .NET:
//ORIGINAL LINE: public com.google.zxing.common.DecoderResult decode(boolean[][] image, java.util.Map<com.google.zxing.DecodeHintType,?> hints) throws com.google.zxing.ChecksumException, com.google.zxing.FormatException
public DecoderResult decode(bool[][] image, IDictionary<DecodeHintType, object> hints)
{
int dimension = image.Length;
BitMatrix bits = new BitMatrix(dimension);
for (int i = 0; i < dimension; i++)
{
for (int j = 0; j < dimension; j++)
{
if (image[i][j])
{
bits.set(j, i);
}
}
}
return decode(bits, hints);
}
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in .NET:
//ORIGINAL LINE: public com.google.zxing.common.DecoderResult decode(com.google.zxing.common.BitMatrix bits) throws com.google.zxing.ChecksumException, com.google.zxing.FormatException
public DecoderResult decode(BitMatrix bits)
{
return decode(bits, null);
}
/// <summary>
/// <p>Decodes a QR Code represented as a <seealso cref="BitMatrix"/>. A 1 or "true" is taken to mean a black module.</p>
/// </summary>
/// <param name="bits"> booleans representing white/black QR Code modules </param>
/// <returns> text and bytes encoded within the QR Code </returns>
/// <exception cref="FormatException"> if the QR Code cannot be decoded </exception>
/// <exception cref="ChecksumException"> if error correction fails </exception>
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in .NET:
//ORIGINAL LINE: public com.google.zxing.common.DecoderResult decode(com.google.zxing.common.BitMatrix bits, java.util.Map<com.google.zxing.DecodeHintType,?> hints) throws com.google.zxing.FormatException, com.google.zxing.ChecksumException
public DecoderResult decode(BitMatrix bits, IDictionary<DecodeHintType, object> hints)
{
// Construct a parser and read version, error-correction level
BitMatrixParser parser = new BitMatrixParser(bits);
Version version = parser.readVersion();
ErrorCorrectionLevel ecLevel = parser.readFormatInformation().ErrorCorrectionLevel;
// Read codewords
sbyte[] codewords = parser.readCodewords();
// Separate into data blocks
DataBlock[] dataBlocks = DataBlock.getDataBlocks(codewords, version, ecLevel);
// Count total number of data bytes
int totalBytes = 0;
foreach (DataBlock dataBlock in dataBlocks)
{
totalBytes += dataBlock.NumDataCodewords;
}
sbyte[] resultBytes = new sbyte[totalBytes];
int resultOffset = 0;
// Error-correct and copy data blocks together into a stream of bytes
foreach (DataBlock dataBlock in dataBlocks)
{
sbyte[] codewordBytes = dataBlock.Codewords;
int numDataCodewords = dataBlock.NumDataCodewords;
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, version, ecLevel, hints);
}
/// <summary>
/// <p>Given data and error-correction codewords received, possibly corrupted by errors, attempts to
/// correct the errors in-place using Reed-Solomon error correction.</p>
/// </summary>
/// <param name="codewordBytes"> data and error correction codewords </param>
/// <param name="numDataCodewords"> number of codewords that are data bytes </param>
/// <exception cref="ChecksumException"> if error correction fails </exception>
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in .NET:
//ORIGINAL LINE: private void correctErrors(byte[] codewordBytes, int numDataCodewords) throws com.google.zxing.ChecksumException
private void correctErrors(sbyte[] codewordBytes, int numDataCodewords)
{
int numCodewords = codewordBytes.Length;
// First read into an array of ints
int[] codewordsInts = new int[numCodewords];
for (int i = 0; i < numCodewords; i++)
{
codewordsInts[i] = codewordBytes[i] & 0xFF;
}
int numECCodewords = codewordBytes.Length - numDataCodewords;
try
{
rsDecoder.decode(codewordsInts, numECCodewords);
}
catch (ReedSolomonException rse)
{
throw ChecksumException.ChecksumInstance;
}
// Copy back into array of bytes -- only need to worry about the bytes that were data
// We don't care about errors in the error-correction codewords
for (int i = 0; i < numDataCodewords; i++)
{
codewordBytes[i] = (sbyte) codewordsInts[i];
}
}
}
}