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)
{
throw ReaderException.Instance;
}
int dimension = computeDimension(topLeft, topRight, bottomLeft, moduleSize);
Version provisionalVersion = Version.getProvisionalVersionForDimension(dimension);
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
float correctionToTopLeft = 1.0f - 3.0f/modulesBetweenFPCenters;
var estAlignmentX = (int) (topLeft.X + correctionToTopLeft*(bottomRightX - topLeft.X));
var 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)
{
try
{
alignmentPattern = findAlignmentInRegion(moduleSize, estAlignmentX, estAlignmentY, i);
break;
}
catch (ReaderException)
{
// try next round
}
}
// If we didn't find alignment pattern... well try anyway without it
}
PerspectiveTransform transform = createTransform(topLeft, topRight, bottomLeft, alignmentPattern, dimension);
BitMatrix bits = sampleGrid(image, transform, dimension);
ResultPoint[] points;
if (alignmentPattern == null)
{
points = new ResultPoint[] {bottomLeft, topLeft, topRight};
}
else
{
points = new ResultPoint[] {bottomLeft, topLeft, topRight, alignmentPattern};
}
return new DetectorResult(bits, points);
}
/// <summary>
/// </summary>
/// <returns>the 3 best <see cref="FinderPattern" />s from our list of candidates. The "best" are
/// those that have been detected at least CENTER_QUORUM times, and whose module
/// size differs from the average among those patterns the least
/// </returns>
private FinderPattern[][] selectMultipleBestPatterns()
{
List <FinderPattern> possibleCenters = PossibleCenters;
int size = possibleCenters.Count;
if (size < 3)
{
// Couldn't find enough finder patterns
return(null);
}
/*
* Begin HE modifications to safely detect multiple codes of equal size
*/
if (size == 3)
{
return(new FinderPattern[][]
{
new FinderPattern[]
{
possibleCenters[0],
possibleCenters[1],
possibleCenters[2]
}
});
}
// Sort by estimated module size to speed up the upcoming checks
possibleCenters.Sort(new ModuleSizeComparator());
/*
* Now lets start: build a list of tuples of three finder locations that
* - feature similar module sizes
* - are placed in a distance so the estimated module count is within the QR specification
* - have similar distance between upper left/right and left top/bottom finder patterns
* - form a triangle with 90° angle (checked by comparing top right/bottom left distance
* with pythagoras)
*
* Note: we allow each point to be used for more than one code region: this might seem
* counterintuitive at first, but the performance penalty is not that big. At this point,
* we cannot make a good quality decision whether the three finders actually represent
* a QR code, or are just by chance layouted so it looks like there might be a QR code there.
* So, if the layout seems right, lets have the decoder try to decode.
*/
List <FinderPattern[]> results = new List <FinderPattern[]>(); // holder for the results
for (int i1 = 0; i1 < (size - 2); i1++)
{
FinderPattern p1 = possibleCenters[i1];
if (p1 == null)
{
continue;
}
for (int i2 = i1 + 1; i2 < (size - 1); i2++)
{
FinderPattern p2 = possibleCenters[i2];
if (p2 == null)
{
continue;
}
// Compare the expected module sizes; if they are really off, skip
float vModSize12 = (p1.EstimatedModuleSize - p2.EstimatedModuleSize) /
Math.Min(p1.EstimatedModuleSize, p2.EstimatedModuleSize);
float vModSize12A = Math.Abs(p1.EstimatedModuleSize - p2.EstimatedModuleSize);
if (vModSize12A > DIFF_MODSIZE_CUTOFF && vModSize12 >= DIFF_MODSIZE_CUTOFF_PERCENT)
{
// break, since elements are ordered by the module size deviation there cannot be
// any more interesting elements for the given p1.
break;
}
for (int i3 = i2 + 1; i3 < size; i3++)
{
FinderPattern p3 = possibleCenters[i3];
if (p3 == null)
{
continue;
}
// Compare the expected module sizes; if they are really off, skip
float vModSize23 = (p2.EstimatedModuleSize - p3.EstimatedModuleSize) /
Math.Min(p2.EstimatedModuleSize, p3.EstimatedModuleSize);
float vModSize23A = Math.Abs(p2.EstimatedModuleSize - p3.EstimatedModuleSize);
if (vModSize23A > DIFF_MODSIZE_CUTOFF && vModSize23 >= DIFF_MODSIZE_CUTOFF_PERCENT)
{
// break, since elements are ordered by the module size deviation there cannot be
// any more interesting elements for the given p1.
break;
}
FinderPattern[] test = { p1, p2, p3 };
ResultPoint.orderBestPatterns(test);
// Calculate the distances: a = topleft-bottomleft, b=topleft-topright, c = diagonal
FinderPatternInfo info = new FinderPatternInfo(test);
float dA = ResultPoint.distance(info.TopLeft, info.BottomLeft);
float dC = ResultPoint.distance(info.TopRight, info.BottomLeft);
float dB = ResultPoint.distance(info.TopLeft, info.TopRight);
// Check the sizes
float estimatedModuleCount = (dA + dB) / (p1.EstimatedModuleSize * 2.0f);
if (estimatedModuleCount > MAX_MODULE_COUNT_PER_EDGE ||
estimatedModuleCount < MIN_MODULE_COUNT_PER_EDGE)
{
continue;
}
// Calculate the difference of the edge lengths in percent
float vABBC = Math.Abs((dA - dB) / Math.Min(dA, dB));
if (vABBC >= 0.1f)
{
continue;
}
// Calculate the diagonal length by assuming a 90° angle at topleft
float dCpy = (float)Math.Sqrt((double)dA * dA + (double)dB * dB);
// Compare to the real distance in %
float vPyC = Math.Abs((dC - dCpy) / Math.Min(dC, dCpy));
if (vPyC >= 0.1f)
{
continue;
}
// All tests passed!
results.Add(test);
} // end iterate p3
} // end iterate p2
} // end iterate p1
if (results.Count != 0)
{
return(results.ToArray());
}
// Nothing found!
return(null);
}
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)
{
throw ReaderException.Instance;
}
int dimension = computeDimension(topLeft, topRight, bottomLeft, moduleSize);
Version provisionalVersion = Version.getProvisionalVersionForDimension(dimension);
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 / 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)
{
try
{
//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'"
alignmentPattern = findAlignmentInRegion(moduleSize, estAlignmentX, estAlignmentY, i);
break;
}
catch (ReaderException)
{
// try next round
}
}
// If we didn't find alignment pattern... well try anyway without it
}
PerspectiveTransform transform = createTransform(topLeft, topRight, bottomLeft, alignmentPattern, dimension);
BitMatrix bits = sampleGrid(_image, transform, dimension);
ResultPoint[] points = alignmentPattern == null ? new ResultPoint[]{bottomLeft, topLeft, topRight} : new ResultPoint[]{bottomLeft, topLeft, topRight, alignmentPattern};
return new DetectorResult(bits, points);
}
