public bool DetectQRCode()
{
var qrReader = new QRCodeMultiReader();
var qrReaderHints = new Dictionary<DecodeHintType, object>() {
{ DecodeHintType.TRY_HARDER, true }
};
var qrImageSource = new BitmapLuminanceSource((Bitmap)Image);
var qrBinarizer = new HybridBinarizer(qrImageSource);
var qrBinaryBitmap = new BinaryBitmap(qrBinarizer);
try
{
qrCodeResult = qrReader.decodeMultiple(qrBinaryBitmap, qrReaderHints)?.FirstOrDefault();
qrCodeResultScale = 1F;
}
catch (ReaderException)
{
// QR Detection Failed
qrCodeResult = null;
}
if (qrCodeResult == null)
{
var sizePoints = PdfiumDocument.PageSizes[PageIndex];
// Try at 175%
using (var image = PdfiumDocument.Render(PageIndex, (int)(sizePoints.Width * 1.75), (int)(sizePoints.Height * 1.75), 72F, 72F, false))
{
qrImageSource = new BitmapLuminanceSource((Bitmap)image);
// Try Entire Image
qrBinarizer = new HybridBinarizer(qrImageSource);
qrBinaryBitmap = new BinaryBitmap(qrBinarizer);
try
{
qrCodeResult = qrReader.decodeMultiple(qrBinaryBitmap, qrReaderHints)?.FirstOrDefault();
qrCodeResultScale = 1.75F;
}
catch (ReaderException)
{
// QR Detection Failed
qrCodeResult = null;
}
}
if (qrCodeResult == null)
{
// Try at 200%
using (var image = PdfiumDocument.Render(PageIndex, (int)(sizePoints.Width * 2), (int)(sizePoints.Height * 2), 72F, 72F, false))
{
qrImageSource = new BitmapLuminanceSource((Bitmap)image);
// Try Entire Image
qrBinarizer = new HybridBinarizer(qrImageSource);
qrBinaryBitmap = new BinaryBitmap(qrBinarizer);
try
{
qrCodeResult = qrReader.decodeMultiple(qrBinaryBitmap, qrReaderHints)?.FirstOrDefault();
qrCodeResultScale = 2F;
}
catch (ReaderException)
{
// QR Detection Failed
qrCodeResult = null;
}
}
}
}
if (qrCodeResult != null)
{
// Detect Rotation
var rotationAngle = Math.Atan2(
qrCodeResult.ResultPoints[2].Y - qrCodeResult.ResultPoints[1].Y,
qrCodeResult.ResultPoints[2].X - qrCodeResult.ResultPoints[1].X) * 180 / Math.PI;
if (rotationAngle <= 45 || rotationAngle > 315)
{
detectedRotation = RotateFlipType.RotateNoneFlipNone;
}
else if (rotationAngle <= 135)
{
detectedRotation = RotateFlipType.Rotate270FlipNone;
}
else if (rotationAngle <= 225)
{
detectedRotation = RotateFlipType.Rotate180FlipNone;
}
else
{
detectedRotation = RotateFlipType.Rotate90FlipNone;
}
// Reset Thumbnail
if (renderedThumbnail != null)
{
renderedThumbnail.Dispose();
renderedThumbnail = null;
}
// Try binary encoding (from v2)
if (qrCodeResult.ResultMetadata.ContainsKey(ResultMetadataType.BYTE_SEGMENTS))
{
var byteSegments = (List<byte[]>)qrCodeResult.ResultMetadata[ResultMetadataType.BYTE_SEGMENTS];
var qrBytes = byteSegments[0];
if (DocumentUniqueIdentifier.IsDocumentUniqueIdentifier(qrBytes))
{
Identifier = DocumentUniqueIdentifier.Parse(Database, qrBytes);
}
}
// Fall back to v1
if (Identifier == null)
{
Identifier = DocumentUniqueIdentifier.Parse(Database, qrCodeResult.Text);
}
return true;
}
return false;
}
/// <summary>
/// Tries to decode barcodes within an image which is given by a luminance source.
/// That method gives a chance to prepare a luminance source completely before calling
/// the time consuming decoding method. On the other hand there is a chance to create
/// a luminance source which is independent from external resources (like Bitmap objects)
/// and the decoding call can be made in a background thread.
/// </summary>
/// <param name="luminanceSource">The luminance source.</param>
/// <returns></returns>
private Result[] DecodeMultiple(LuminanceSource luminanceSource)
{
var results = default(Result[]);
var binarizer = CreateBinarizer(luminanceSource);
var binaryBitmap = new BinaryBitmap(binarizer);
var rotationCount = 0;
var rotationMaxCount = 1;
MultipleBarcodeReader multiReader = null;
if (AutoRotate)
{
Options.Hints[DecodeHintType.TRY_HARDER_WITHOUT_ROTATION] = true;
rotationMaxCount = 4;
}
var formats = Options.PossibleFormats;
if (formats != null &&
formats.Length == 1 &&
formats[0] == BarcodeFormat.QR_CODE)
{
multiReader = new QRCodeMultiReader();
}
else
{
multiReader = new GenericMultipleBarcodeReader(Reader);
}
for (; rotationCount < rotationMaxCount; rotationCount++)
{
results = multiReader.decodeMultiple(binaryBitmap, Options.Hints);
if (results == null)
{
if (TryInverted && luminanceSource.InversionSupported)
{
binaryBitmap = new BinaryBitmap(CreateBinarizer(luminanceSource.invert()));
results = multiReader.decodeMultiple(binaryBitmap, Options.Hints);
}
}
if (results != null ||
!luminanceSource.RotateSupported ||
!AutoRotate)
break;
binaryBitmap = new BinaryBitmap(CreateBinarizer(luminanceSource.rotateCounterClockwise()));
}
if (results != null)
{
foreach (var result in results)
{
if (result.ResultMetadata == null)
{
result.putMetadata(ResultMetadataType.ORIENTATION, rotationCount * 90);
}
else if (!result.ResultMetadata.ContainsKey(ResultMetadataType.ORIENTATION))
{
result.ResultMetadata[ResultMetadataType.ORIENTATION] = rotationCount * 90;
}
else
{
// perhaps the core decoder rotates the image already (can happen if TryHarder is specified)
result.ResultMetadata[ResultMetadataType.ORIENTATION] =
((int)(result.ResultMetadata[ResultMetadataType.ORIENTATION]) + rotationCount * 90) % 360;
}
}
OnResultsFound(results);
}
return results;
}
