/// <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.
///
/// @see com.google.zxing.pdf417.PDF417Reader#extractPureBits(BitMatrix)
/// @see com.google.zxing.qrcode.QRCodeReader#extractPureBits(BitMatrix)
/// </summary>
private static BitMatrix extractPureBits(BitMatrix image)
{
int[] leftTopBlack = image.getTopLeftOnBit();
int[] rightBottomBlack = image.getBottomRightOnBit();
if (leftTopBlack == null || rightBottomBlack == null)
{
return null;
}
int moduleSize;
if (!DataMatrixReader.moduleSize(leftTopBlack, image, out moduleSize))
return null;
int top = leftTopBlack[1];
int bottom = rightBottomBlack[1];
int left = leftTopBlack[0];
int right = rightBottomBlack[0];
int matrixWidth = (right - left + 1) / moduleSize;
int matrixHeight = (bottom - top + 1) / moduleSize;
if (matrixWidth <= 0 || matrixHeight <= 0)
{
return null;
}
// 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[left + x * moduleSize, iOffset])
{
bits[x, y] = true;
}
}
}
return bits;
}
/// <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.
///
/// <seealso cref="ZXing.PDF417.PDF417Reader.extractPureBits(BitMatrix)" />
/// <seealso cref="ZXing.Datamatrix.DataMatrixReader.extractPureBits(BitMatrix)" />
/// </summary>
private static BitMatrix extractPureBits(BitMatrix image)
{
int[] leftTopBlack = image.getTopLeftOnBit();
int[] rightBottomBlack = image.getBottomRightOnBit();
if (leftTopBlack == null || rightBottomBlack == null)
{
return null;
}
float moduleSize;
if (!QRCodeReader.moduleSize(leftTopBlack, image, out moduleSize))
return null;
int top = leftTopBlack[1];
int bottom = rightBottomBlack[1];
int left = leftTopBlack[0];
int right = rightBottomBlack[0];
if (bottom - top != right - left)
{
// Special case, where bottom-right module wasn't black so we found something else in the last row
// Assume it's a square, so use height as the width
right = left + (bottom - top);
}
int matrixWidth = (int)Math.Round((right - left + 1) / moduleSize);
int matrixHeight = (int)Math.Round((bottom - top + 1) / moduleSize);
if (matrixWidth <= 0 || matrixHeight <= 0)
{
return null;
}
if (matrixHeight != matrixWidth)
{
// Only possibly decode square regions
return null;
}
// 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 = (int)(moduleSize / 2.0f);
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 + (int)(y * moduleSize);
for (int x = 0; x < matrixWidth; x++)
{
if (image[left + (int)(x * moduleSize), iOffset])
{
bits[x, y] = true;
}
}
}
return bits;
}
/// <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.
///
/// <seealso cref="ZXing.Datamatrix.DataMatrixReader.extractPureBits(BitMatrix)" />
/// </summary>
private static BitMatrix extractPureBits(BitMatrix image)
{
int[] leftTopBlack = image.getTopLeftOnBit();
int[] rightBottomBlack = image.getBottomRightOnBit();
if (leftTopBlack == null || rightBottomBlack == null)
{
return null;
}
float moduleSize;
if (!QRCodeReader.moduleSize(leftTopBlack, image, out moduleSize))
return null;
int top = leftTopBlack[1];
int bottom = rightBottomBlack[1];
int left = leftTopBlack[0];
int right = rightBottomBlack[0];
// Sanity check!
if (left >= right || top >= bottom)
{
return null;
}
if (bottom - top != right - left)
{
// Special case, where bottom-right module wasn't black so we found something else in the last row
// Assume it's a square, so use height as the width
right = left + (bottom - top);
}
int matrixWidth = (int)Math.Round((right - left + 1) / moduleSize);
int matrixHeight = (int)Math.Round((bottom - top + 1) / moduleSize);
if (matrixWidth <= 0 || matrixHeight <= 0)
{
return null;
}
if (matrixHeight != matrixWidth)
{
// Only possibly decode square regions
return null;
}
// 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 = (int)(moduleSize / 2.0f);
top += nudge;
left += nudge;
// But careful that this does not sample off the edge
// "right" is the farthest-right valid pixel location -- right+1 is not necessarily
// This is positive by how much the inner x loop below would be too large
int nudgedTooFarRight = left + (int)((matrixWidth - 1) * moduleSize) - right;
if (nudgedTooFarRight > 0)
{
if (nudgedTooFarRight > nudge)
{
// Neither way fits; abort
return null;
}
left -= nudgedTooFarRight;
}
// See logic above
int nudgedTooFarDown = top + (int)((matrixHeight - 1) * moduleSize) - bottom;
if (nudgedTooFarDown > 0)
{
if (nudgedTooFarDown > nudge)
{
// Neither way fits; abort
return null;
}
top -= nudgedTooFarDown;
}
// Now just read off the bits
BitMatrix bits = new BitMatrix(matrixWidth, matrixHeight);
for (int y = 0; y < matrixHeight; y++)
{
int iOffset = top + (int)(y * moduleSize);
for (int x = 0; x < matrixWidth; x++)
{
if (image[left + (int)(x * moduleSize), iOffset])
{
bits[x, y] = true;
}
}
}
return bits;
}
