/// <summary>
/// <p>Detects a QR Code in an image.</p>
/// </summary>
/// <returns>
/// <see cref="DetectorResult"/> encapsulating results of detecting a QR Code
/// </returns>
public virtual DetectorResult Detect()
{
FinderPatternFinder finder = new FinderPatternFinder(image);
FinderPatternInfo info = finder.Find();
if (info == null)
{
return(null);
}
return(ProcessFinderPatternInfo(info));
}
/// <summary>
/// Processes the finder pattern info.
/// </summary>
/// <param name="info">The info.</param>
/// <returns></returns>
protected internal virtual DetectorResult ProcessFinderPatternInfo(FinderPatternInfo info)
{
FinderPattern topLeft = info.TopLeft;
FinderPattern topRight = info.TopRight;
FinderPattern bottomLeft = info.BottomLeft;
float moduleSize = CalculateModuleSize(topLeft, topRight, bottomLeft);
if (moduleSize < 1.0f)
{
return(null);
}
if (!ComputeDimension(topLeft, topRight, bottomLeft, moduleSize, out int dimension))
{
return(null);
}
Version provisionalVersion = Version.GetProvisionalVersionForDimension(dimension);
if (provisionalVersion == null)
{
return(null);
}
int modulesBetweenFPCenters = provisionalVersion.DimensionForVersion - 7;
AlignmentPattern alignmentPattern = null;
// Anything above version 1 has an alignment pattern
if (provisionalVersion.AlignmentPatternCenters.Length > 0)
{
// Guess where a "bottom right" finder pattern would have been
float bottomRightX = topRight.X - topLeft.X + bottomLeft.X;
float bottomRightY = topRight.Y - topLeft.Y + bottomLeft.Y;
// Estimate that alignment pattern is closer by 3 modules
// from "bottom right" to known top left location
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
float correctionToTopLeft = 1.0f - 3.0f / (float)modulesBetweenFPCenters;
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
int estAlignmentX = (int)(topLeft.X + correctionToTopLeft * (bottomRightX - topLeft.X));
//UPGRADE_WARNING: Data types in Visual C# might be different. Verify the accuracy of narrowing conversions. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1042'"
int estAlignmentY = (int)(topLeft.Y + correctionToTopLeft * (bottomRightY - topLeft.Y));
// Kind of arbitrary -- expand search radius before giving up
for (int i = 4; i <= 16; i <<= 1)
{
alignmentPattern = FindAlignmentInRegion(moduleSize, estAlignmentX, estAlignmentY, (float)i);
if (alignmentPattern == null)
{
continue;
}
break;
}
// If we didn't find alignment pattern... well try anyway without it
}
PerspectiveTransform transform = CreateTransform(topLeft, topRight, bottomLeft, alignmentPattern, dimension);
BitMatrix bits = GridSampler.SampleGrid(image, dimension, dimension, transform);
if (bits == null)
{
return(null);
}
ResultPoint[] points;
if (alignmentPattern == null)
{
points = new ResultPoint[] { bottomLeft, topLeft, topRight };
}
else
{
points = new ResultPoint[] { bottomLeft, topLeft, topRight, alignmentPattern };
}
return(new DetectorResult(bits, points));
}
