zxing/csharp/pdf417/PDF417Reader.cs

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using System.Collections.Generic;
/*
* Copyright 2009 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.pdf417
{
using BarcodeFormat = com.google.zxing.BarcodeFormat;
using BinaryBitmap = com.google.zxing.BinaryBitmap;
using ChecksumException = com.google.zxing.ChecksumException;
using DecodeHintType = com.google.zxing.DecodeHintType;
using FormatException = com.google.zxing.FormatException;
using NotFoundException = com.google.zxing.NotFoundException;
using Reader = com.google.zxing.Reader;
using Result = com.google.zxing.Result;
using ResultPoint = com.google.zxing.ResultPoint;
using BitMatrix = com.google.zxing.common.BitMatrix;
using DecoderResult = com.google.zxing.common.DecoderResult;
using DetectorResult = com.google.zxing.common.DetectorResult;
using Decoder = com.google.zxing.pdf417.decoder.Decoder;
using Detector = com.google.zxing.pdf417.detector.Detector;
/// <summary>
/// This implementation can detect and decode PDF417 codes in an image.
///
/// @author SITA Lab (kevin.osullivan@sita.aero)
/// </summary>
public sealed class PDF417Reader : com.google.zxing.Reader
{
private static readonly ResultPoint[] NO_POINTS = new ResultPoint[0];
private readonly Decoder decoder = new Decoder();
/// <summary>
/// Locates and decodes a PDF417 code in an image.
/// </summary>
/// <returns> a String representing the content encoded by the PDF417 code </returns>
/// <exception cref="NotFoundException"> if a PDF417 code cannot be found, </exception>
/// <exception cref="FormatException"> if a PDF417 cannot be decoded </exception>
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in .NET:
//ORIGINAL LINE: public com.google.zxing.Result decode(com.google.zxing.BinaryBitmap image) throws com.google.zxing.NotFoundException, com.google.zxing.FormatException, com.google.zxing.ChecksumException
public Result decode(BinaryBitmap image)
{
return decode(image, null);
}
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in .NET:
//ORIGINAL LINE: public com.google.zxing.Result decode(com.google.zxing.BinaryBitmap image, java.util.Map<com.google.zxing.DecodeHintType,?> hints) throws com.google.zxing.NotFoundException, com.google.zxing.FormatException, com.google.zxing.ChecksumException
public Result decode(BinaryBitmap image, IDictionary<DecodeHintType, object> hints)
{
DecoderResult decoderResult;
ResultPoint[] points;
if (hints != null && hints.ContainsKey(DecodeHintType.PURE_BARCODE))
{
BitMatrix bits = extractPureBits(image.BlackMatrix);
decoderResult = decoder.decode(bits);
points = NO_POINTS;
}
else
{
DetectorResult detectorResult = (new Detector(image)).detect();
decoderResult = decoder.decode(detectorResult.Bits);
points = detectorResult.Points;
}
return new Result(decoderResult.Text, decoderResult.RawBytes, points, BarcodeFormat.PDF_417);
}
public void reset()
{
// do nothing
}
/// <summary>
/// This method detects a code in a "pure" image -- that is, pure monochrome image
/// which contains only an unrotated, unskewed, image of a code, with some white border
/// around it. This is a specialized method that works exceptionally fast in this special
/// case.
/// </summary>
/// <seealso cref= com.google.zxing.qrcode.QRCodeReader#extractPureBits(BitMatrix) </seealso>
/// <seealso cref= com.google.zxing.datamatrix.DataMatrixReader#extractPureBits(BitMatrix) </seealso>
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in .NET:
//ORIGINAL LINE: private static com.google.zxing.common.BitMatrix extractPureBits(com.google.zxing.common.BitMatrix image) throws com.google.zxing.NotFoundException
private static BitMatrix extractPureBits(BitMatrix image)
{
int[] leftTopBlack = image.TopLeftOnBit;
int[] rightBottomBlack = image.BottomRightOnBit;
if (leftTopBlack == null || rightBottomBlack == null)
{
throw NotFoundException.NotFoundInstance;
}
int moduleSize = getModuleSize(leftTopBlack, image);
int top = leftTopBlack[1];
int bottom = rightBottomBlack[1];
int left = findPatternStart(leftTopBlack[0], top, image);
int right = findPatternEnd(leftTopBlack[0], top, image);
int matrixWidth = (right - left + 1) / moduleSize;
int matrixHeight = (bottom - top + 1) / moduleSize;
if (matrixWidth <= 0 || matrixHeight <= 0)
{
throw NotFoundException.NotFoundInstance;
}
// Push in the "border" by half the module width so that we start
// sampling in the middle of the module. Just in case the image is a
// little off, this will help recover.
int nudge = moduleSize >> 1;
top += nudge;
left += nudge;
// Now just read off the bits
BitMatrix bits = new BitMatrix(matrixWidth, matrixHeight);
for (int y = 0; y < matrixHeight; y++)
{
int iOffset = top + y * moduleSize;
for (int x = 0; x < matrixWidth; x++)
{
if (image.get(left + x * moduleSize, iOffset))
{
bits.set(x, y);
}
}
}
return bits;
}
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in .NET:
//ORIGINAL LINE: private static int moduleSize(int[] leftTopBlack, com.google.zxing.common.BitMatrix image) throws com.google.zxing.NotFoundException
private static int getModuleSize(int[] leftTopBlack, BitMatrix image)
{
int x = leftTopBlack[0];
int y = leftTopBlack[1];
int width = image.Width;
while (x < width && image.get(x, y))
{
x++;
}
if (x == width)
{
throw NotFoundException.NotFoundInstance;
}
int moduleSize = (int)((uint)(x - leftTopBlack[0]) >> 3); // We've crossed left first bar, which is 8x
if (moduleSize == 0)
{
throw NotFoundException.NotFoundInstance;
}
return moduleSize;
}
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in .NET:
//ORIGINAL LINE: private static int findPatternStart(int x, int y, com.google.zxing.common.BitMatrix image) throws com.google.zxing.NotFoundException
private static int findPatternStart(int x, int y, BitMatrix image)
{
int width = image.Width;
int start = x;
// start should be on black
int transitions = 0;
bool black = true;
while (start < width - 1 && transitions < 8)
{
start++;
bool newBlack = image.get(start, y);
if (black != newBlack)
{
transitions++;
}
black = newBlack;
}
if (start == width - 1)
{
throw NotFoundException.NotFoundInstance;
}
return start;
}
//JAVA TO C# CONVERTER WARNING: Method 'throws' clauses are not available in .NET:
//ORIGINAL LINE: private static int findPatternEnd(int x, int y, com.google.zxing.common.BitMatrix image) throws com.google.zxing.NotFoundException
private static int findPatternEnd(int x, int y, BitMatrix image)
{
int width = image.Width;
int end = width - 1;
// end should be on black
while (end > x && !image.get(end, y))
{
end--;
}
int transitions = 0;
bool black = true;
while (end > x && transitions < 9)
{
end--;
bool newBlack = image.get(end, y);
if (black != newBlack)
{
transitions++;
}
black = newBlack;
}
if (end == x)
{
throw NotFoundException.NotFoundInstance;
}
return end;
}
}
}