public FinderPatternFinder(BitMatrix image, ResultPointCallback resultPointCallback)
{
this.image = image;
this.possibleCenters = new System.Collections.Generic.List<Object>(10);
this.crossCheckStateCount = new int[5];
this.resultPointCallback = resultPointCallback;
}
/// <param name="bitMatrix">{@link BitMatrix} to parse
/// </param>
/// <throws> ReaderException if dimension is not >= 21 and 1 mod 4 </throws>
internal BitMatrixParser(BitMatrix bitMatrix)
{
int dimension = bitMatrix.Dimension;
if (dimension < 21 || (dimension & 0x03) != 1)
{
throw ReaderException.Instance;
}
this.bitMatrix = bitMatrix;
}
public BinaryBitmap(Binarizer binarizer)
{
if (binarizer == null)
{
throw new System.ArgumentException("Binarizer must be non-null.");
}
this.binarizer = binarizer;
matrix = null;
}
/// <summary> <p>Implementations of this method reverse the data masking process applied to a QR Code and
/// make its bits ready to read.</p>
///
/// </summary>
/// <param name="bits">representation of QR Code bits
/// </param>
/// <param name="dimension">dimension of QR Code, represented by bits, being unmasked
/// </param>
internal void unmaskBitMatrix(BitMatrix bits, int dimension)
{
for (int i = 0; i < dimension; i++)
{
for (int j = 0; j < dimension; j++)
{
if (isMasked(i, j))
{
bits.flip(j, i);
}
}
}
}
/// <summary> <p>Convenience method that can decode a PDF417 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 PDF417 modules
/// </param>
/// <returns> text and bytes encoded within the PDF417 Code
/// </returns>
/// <throws> ReaderException if the PDF417 Code cannot be decoded </throws>
public DecoderResult decode(bool[][] image)
{
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[j][i])
{
bits.set_Renamed(j, i);
}
}
}
return decode(bits);
}
/// <param name="matrix">row of black/white values to search
/// </param>
/// <param name="column">x position to start search
/// </param>
/// <param name="row">y position to start search
/// </param>
/// <param name="width">the number of pixels to search on this row
/// </param>
/// <param name="pattern">pattern of counts of number of black and white pixels that are
/// being searched for as a pattern
/// </param>
/// <returns> start/end horizontal offset of guard pattern, as an array of two ints.
/// </returns>
private static int[] findGuardPattern(BitMatrix matrix, int column, int row, int width, bool whiteFirst, int[] pattern)
{
int patternLength = pattern.Length;
// TODO: Find a way to cache this array, as this method is called hundreds of times
// per image, and we want to allocate as seldom as possible.
int[] counters = new int[patternLength];
bool isWhite = whiteFirst;
int counterPosition = 0;
int patternStart = column;
for (int x = column; x < column + width; x++)
{
bool pixel = matrix.get_Renamed(x, row);
if (pixel ^ isWhite)
{
counters[counterPosition]++;
}
else
{
if (counterPosition == patternLength - 1)
{
if (patternMatchVariance(counters, pattern, MAX_INDIVIDUAL_VARIANCE) < MAX_AVG_VARIANCE)
{
return new int[]{patternStart, x};
}
patternStart += counters[0] + counters[1];
for (int y = 2; y < patternLength; y++)
{
counters[y - 2] = counters[y];
}
counters[patternLength - 2] = 0;
counters[patternLength - 1] = 0;
counterPosition--;
}
else
{
counterPosition++;
}
counters[counterPosition] = 1;
isWhite = !isWhite;
}
}
return null;
}
/// <summary> <p>Decodes a PDF417 Code represented as a {@link BitMatrix}.
/// A 1 or "true" is taken to mean a black module.</p>
///
/// </summary>
/// <param name="bits">booleans representing white/black PDF417 Code modules
/// </param>
/// <returns> text and bytes encoded within the PDF417 Code
/// </returns>
/// <throws> ReaderException if the PDF417 Code cannot be decoded </throws>
public DecoderResult decode(BitMatrix bits)
{
// Construct a parser to read the data codewords and error-correction level
BitMatrixParser parser = new BitMatrixParser(bits);
int[] codewords = parser.readCodewords();
if (codewords == null || codewords.Length == 0)
{
throw ReaderException.Instance;
}
int ecLevel = parser.ECLevel;
int numECCodewords = 1 << (ecLevel + 1);
int[] erasures = parser.Erasures;
correctErrors(codewords, erasures, numECCodewords);
verifyCodewordCount(codewords, numECCodewords);
// Decode the codewords
return DecodedBitStreamParser.decode(codewords);
}
public Detector(BitMatrix image)
{
this.image = image;
}
public Detector(BitMatrix image)
{
this.image = image;
rectangleDetector = new MonochromeRectangleDetector(image);
}
/// <summary> <p>Creates a finder that will search the image for three finder patterns.</p>
///
/// </summary>
/// <param name="image">image to search
/// </param>
internal MultiFinderPatternFinder(BitMatrix image)
: base(image)
{
}
internal BitMatrixParser(BitMatrix bitMatrix)
{
this.bitMatrix = bitMatrix;
}
/// <summary> This method detects a Data Matrix code in a "pure" image -- that is, pure monochrome image
/// which contains only an unrotated, unskewed, image of a Data Matrix code, with some white border
/// around it. This is a specialized method that works exceptionally fast in this special
/// case.
/// </summary>
private static BitMatrix extractPureBits(BitMatrix image)
{
// Now need to determine module size in pixels
int height = image.Height;
int width = image.Width;
int minDimension = System.Math.Min(height, width);
// First, skip white border by tracking diagonally from the top left down and to the right:
int borderWidth = 0;
while (borderWidth < minDimension && !image.get_Renamed(borderWidth, borderWidth))
{
borderWidth++;
}
if (borderWidth == minDimension)
{
throw ReaderException.Instance;
}
// And then keep tracking across the top-left black module to determine module size
int moduleEnd = borderWidth + 1;
while (moduleEnd < width && image.get_Renamed(moduleEnd, borderWidth))
{
moduleEnd++;
}
if (moduleEnd == width)
{
throw ReaderException.Instance;
}
int moduleSize = moduleEnd - borderWidth;
// And now find where the bottommost black module on the first column ends
int columnEndOfSymbol = height - 1;
while (columnEndOfSymbol >= 0 && !image.get_Renamed(borderWidth, columnEndOfSymbol))
{
columnEndOfSymbol--;
}
if (columnEndOfSymbol < 0)
{
throw ReaderException.Instance;
}
columnEndOfSymbol++;
// Make sure width of barcode is a multiple of module size
if ((columnEndOfSymbol - borderWidth) % moduleSize != 0)
{
throw ReaderException.Instance;
}
int dimension = (columnEndOfSymbol - borderWidth) / moduleSize;
// 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.
borderWidth += (moduleSize >> 1);
int sampleDimension = borderWidth + (dimension - 1) * moduleSize;
if (sampleDimension >= width || sampleDimension >= height)
{
throw ReaderException.Instance;
}
// Now just read off the bits
BitMatrix bits = new BitMatrix(dimension);
for (int i = 0; i < dimension; i++)
{
int iOffset = borderWidth + i * moduleSize;
for (int j = 0; j < dimension; j++)
{
if (image.get_Renamed(borderWidth + j * moduleSize, iOffset))
{
bits.set_Renamed(j, i);
}
}
}
return bits;
}
/// <summary> <p>Decodes a Data Matrix Code represented as a {@link BitMatrix}. A 1 or "true" is taken
/// to mean a black module.</p>
///
/// </summary>
/// <param name="bits">booleans representing white/black Data Matrix Code modules
/// </param>
/// <returns> text and bytes encoded within the Data Matrix Code
/// </returns>
/// <throws> ReaderException if the Data Matrix Code cannot be decoded </throws>
public DecoderResult decode(BitMatrix bits)
{
// Construct a parser and read version, error-correction level
BitMatrixParser parser = new BitMatrixParser(bits);
Version version = parser.readVersion(bits);
// Read codewords
sbyte[] 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].NumDataCodewords;
}
sbyte[] resultBytes = new sbyte[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];
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);
}
/// <summary> <p>Creates a finder that will search the image for three finder patterns.</p>
///
/// </summary>
/// <param name="image">image to search
/// </param>
public FinderPatternFinder(BitMatrix image)
: this(image, null)
{
}
/// <summary> Locate the vertices and the codewords area of a black blob using the Start
/// and Stop patterns as locators. This assumes that the image is rotated 180
/// degrees and if it locates the start and stop patterns at it will re-map
/// the vertices for a 0 degree rotation.
/// TODO: Change assumption about barcode location.
/// TODO: Scanning every row is very expensive. We should only do this for TRY_HARDER.
///
/// </summary>
/// <param name="matrix">the scanned barcode image.
/// </param>
/// <returns> an array containing the vertices:
/// vertices[0] x, y top left barcode
/// vertices[1] x, y bottom left barcode
/// vertices[2] x, y top right barcode
/// vertices[3] x, y bottom right barcode
/// vertices[4] x, y top left codeword area
/// vertices[5] x, y bottom left codeword area
/// vertices[6] x, y top right codeword area
/// vertices[7] x, y bottom right codeword area
/// </returns>
private static ResultPoint[] findVertices180(BitMatrix matrix)
{
int height = matrix.Height;
int width = matrix.Width;
int halfWidth = width >> 1;
ResultPoint[] result = new ResultPoint[8];
bool found = false;
// Top Left
for (int i = height - 1; i > 0; i--)
{
int[] loc = findGuardPattern(matrix, halfWidth, i, halfWidth, true, START_PATTERN_REVERSE);
if (loc != null)
{
result[0] = new ResultPoint(loc[1], i);
result[4] = new ResultPoint(loc[0], i);
found = true;
break;
}
}
// Bottom Left
if (found)
{
// Found the Top Left vertex
found = false;
for (int i = 0; i < height; i++)
{
int[] loc = findGuardPattern(matrix, halfWidth, i, halfWidth, true, START_PATTERN_REVERSE);
if (loc != null)
{
result[1] = new ResultPoint(loc[1], i);
result[5] = new ResultPoint(loc[0], i);
found = true;
break;
}
}
}
// Top Right
if (found)
{
// Found the Bottom Left vertex
found = false;
for (int i = height - 1; i > 0; i--)
{
int[] loc = findGuardPattern(matrix, 0, i, halfWidth, false, STOP_PATTERN_REVERSE);
if (loc != null)
{
result[2] = new ResultPoint(loc[0], i);
result[6] = new ResultPoint(loc[1], i);
found = true;
break;
}
}
}
// Bottom Right
if (found)
{
// Found the Top Right vertex
found = false;
for (int i = 0; i < height; i++)
{
int[] loc = findGuardPattern(matrix, 0, i, halfWidth, false, STOP_PATTERN_REVERSE);
if (loc != null)
{
result[3] = new ResultPoint(loc[0], i);
result[7] = new ResultPoint(loc[1], i);
found = true;
break;
}
}
}
return found?result:null;
}
/// <summary> This method detects a barcode in a "pure" image -- that is, pure monochrome image
/// which contains only an unrotated, unskewed, image of a barcode, with some white border
/// around it. This is a specialized method that works exceptionally fast in this special
/// case.
/// </summary>
private static BitMatrix extractPureBits(BinaryBitmap image)
{
// Now need to determine module size in pixels
BitMatrix matrix = image.BlackMatrix;
int height = matrix.Height;
int width = matrix.Width;
int minDimension = System.Math.Min(height, width);
// First, skip white border by tracking diagonally from the top left down and to the right:
int borderWidth = 0;
while (borderWidth < minDimension && !matrix.get_Renamed(borderWidth, borderWidth))
{
borderWidth++;
}
if (borderWidth == minDimension)
{
throw ReaderException.Instance;
}
// And then keep tracking across the top-left black module to determine module size
int moduleEnd = borderWidth;
while (moduleEnd < minDimension && matrix.get_Renamed(moduleEnd, moduleEnd))
{
moduleEnd++;
}
if (moduleEnd == minDimension)
{
throw ReaderException.Instance;
}
int moduleSize = moduleEnd - borderWidth;
// And now find where the rightmost black module on the first row ends
int rowEndOfSymbol = width - 1;
while (rowEndOfSymbol >= 0 && !matrix.get_Renamed(rowEndOfSymbol, borderWidth))
{
rowEndOfSymbol--;
}
if (rowEndOfSymbol < 0)
{
throw ReaderException.Instance;
}
rowEndOfSymbol++;
// Make sure width of barcode is a multiple of module size
if ((rowEndOfSymbol - borderWidth) % moduleSize != 0)
{
throw ReaderException.Instance;
}
int dimension = (rowEndOfSymbol - borderWidth) / moduleSize;
// 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.
borderWidth += (moduleSize >> 1);
int sampleDimension = borderWidth + (dimension - 1) * moduleSize;
if (sampleDimension >= width || sampleDimension >= height)
{
throw ReaderException.Instance;
}
// Now just read off the bits
BitMatrix bits = new BitMatrix(dimension);
for (int y = 0; y < dimension; y++)
{
int iOffset = borderWidth + y * moduleSize;
for (int x = 0; x < dimension; x++)
{
if (matrix.get_Renamed(borderWidth + x * moduleSize, iOffset))
{
bits.set_Renamed(x, y);
}
}
}
return bits;
}
private static BitMatrix sampleGrid(BitMatrix matrix, ResultPoint topLeft, ResultPoint bottomLeft, ResultPoint topRight, ResultPoint bottomRight, int dimension)
{
// Note that unlike the QR Code sampler, we didn't find the center of modules, but the
// very corners. So there is no 0.5f here; 0.0f is right.
GridSampler sampler = GridSampler.Instance;
return sampler.sampleGrid(matrix, dimension, 0.0f, 0.0f, dimension, 0.0f, dimension, dimension, 0.0f, dimension, topLeft.X, topLeft.Y, topRight.X, topRight.Y, bottomRight.X, bottomRight.Y, bottomLeft.X, bottomLeft.Y); // p4FromY
}
private static BitMatrix sampleGrid(BitMatrix image, PerspectiveTransform transform, int dimension)
{
GridSampler sampler = GridSampler.Instance;
return sampler.sampleGrid(image, dimension, transform);
}
internal MultiFinderPatternFinder(BitMatrix image, ResultPointCallback resultPointCallback)
: base(image, resultPointCallback)
{
}
private static BitMatrix sampleGrid(BitMatrix image, ResultPoint topLeft, ResultPoint bottomLeft, ResultPoint bottomRight, int dimension)
{
// We make up the top right point for now, based on the others.
// TODO: we actually found a fourth corner above and figured out which of two modules
// it was the corner of. We could use that here and adjust for perspective distortion.
float topRightX = (bottomRight.X - bottomLeft.X) + topLeft.X;
float topRightY = (bottomRight.Y - bottomLeft.Y) + topLeft.Y;
// Note that unlike in the QR Code sampler, we didn't find the center of modules, but the
// very corners. So there is no 0.5f here; 0.0f is right.
GridSampler sampler = GridSampler.Instance;
return sampler.sampleGrid(image, dimension, 0.0f, 0.0f, dimension, 0.0f, dimension, dimension, 0.0f, dimension, topLeft.X, topLeft.Y, topRightX, topRightY, bottomRight.X, bottomRight.Y, bottomLeft.X, bottomLeft.Y);
}