/// <summary> <p>Detects a Data Matrix Code in an image.</p>
///
/// </summary>
/// <returns> {@link DetectorResult} encapsulating results of detecting a QR Code
/// </returns>
/// <throws> ReaderException if no Data Matrix Code can be found </throws>
public DetectorResult detect()
{
ResultPoint[] cornerPoints = rectangleDetector.detect();
ResultPoint pointA = cornerPoints[0];
ResultPoint pointB = cornerPoints[1];
ResultPoint pointC = cornerPoints[2];
ResultPoint pointD = cornerPoints[3];
// Point A and D are across the diagonal from one another,
// as are B and C. Figure out which are the solid black lines
// by counting transitions
System.Collections.ArrayList transitions = System.Collections.ArrayList.Synchronized(new System.Collections.ArrayList(4));
transitions.Add(transitionsBetween(pointA, pointB));
transitions.Add(transitionsBetween(pointA, pointC));
transitions.Add(transitionsBetween(pointB, pointD));
transitions.Add(transitionsBetween(pointC, pointD));
Collections.insertionSort(transitions, new ResultPointsAndTransitionsComparator());
// Sort by number of transitions. First two will be the two solid sides; last two
// will be the two alternating black/white sides
ResultPointsAndTransitions lSideOne = (ResultPointsAndTransitions)transitions[0];
ResultPointsAndTransitions lSideTwo = (ResultPointsAndTransitions)transitions[1];
// Figure out which point is their intersection by tallying up the number of times we see the
// endpoints in the four endpoints. One will show up twice.
System.Collections.Hashtable pointCount = System.Collections.Hashtable.Synchronized(new System.Collections.Hashtable());
increment(pointCount, lSideOne.From);
increment(pointCount, lSideOne.To);
increment(pointCount, lSideTwo.From);
increment(pointCount, lSideTwo.To);
ResultPoint maybeTopLeft = null;
ResultPoint bottomLeft = null;
ResultPoint maybeBottomRight = null;
System.Collections.IEnumerator points = pointCount.Keys.GetEnumerator();
//UPGRADE_TODO: Method 'java.util.Enumeration.hasMoreElements' was converted to 'System.Collections.IEnumerator.MoveNext' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javautilEnumerationhasMoreElements'"
while (points.MoveNext())
{
//UPGRADE_TODO: Method 'java.util.Enumeration.nextElement' was converted to 'System.Collections.IEnumerator.Current' which has a different behavior. "ms-help://MS.VSCC.v80/dv_commoner/local/redirect.htm?index='!DefaultContextWindowIndex'&keyword='jlca1073_javautilEnumerationnextElement'"
ResultPoint point = (ResultPoint)points.Current;
System.Int32 value_Renamed = (System.Int32)pointCount[point];
if (value_Renamed == 2)
{
bottomLeft = point; // this is definitely the bottom left, then -- end of two L sides
}
else
{
// Otherwise it's either top left or bottom right -- just assign the two arbitrarily now
if (maybeTopLeft == null)
{
maybeTopLeft = point;
}
else
{
maybeBottomRight = point;
}
}
}
if (maybeTopLeft == null || bottomLeft == null || maybeBottomRight == null)
{
throw ReaderException.Instance;
}
// Bottom left is correct but top left and bottom right might be switched
ResultPoint[] corners = new ResultPoint[] { maybeTopLeft, bottomLeft, maybeBottomRight };
// Use the dot product trick to sort them out
ResultPoint.orderBestPatterns(corners);
// Now we know which is which:
ResultPoint bottomRight = corners[0];
bottomLeft = corners[1];
ResultPoint topLeft = corners[2];
// Which point didn't we find in relation to the "L" sides? that's the top right corner
ResultPoint topRight;
if (!pointCount.ContainsKey(pointA))
{
topRight = pointA;
}
else if (!pointCount.ContainsKey(pointB))
{
topRight = pointB;
}
else if (!pointCount.ContainsKey(pointC))
{
topRight = pointC;
}
else
{
topRight = pointD;
}
// Next determine the dimension by tracing along the top or right side and counting black/white
// transitions. Since we start inside a black module, we should see a number of transitions
// equal to 1 less than the code dimension. Well, actually 2 less, because we are going to
// end on a black module:
// The top right point is actually the corner of a module, which is one of the two black modules
// adjacent to the white module at the top right. Tracing to that corner from either the top left
// or bottom right should work here. The number of transitions could be higher than it should be
// due to noise. So we try both and take the min.
int dimension = System.Math.Min(transitionsBetween(topLeft, topRight).Transitions, transitionsBetween(bottomRight, topRight).Transitions);
if ((dimension & 0x01) == 1)
{
// it can't be odd, so, round... up?
dimension++;
}
dimension += 2;
BitMatrix bits = sampleGrid(image, topLeft, bottomLeft, bottomRight, dimension);
return(new DetectorResult(bits, new ResultPoint[] { pointA, pointB, pointC, pointD }));
}
internal virtual FinderPatternInfo find(System.Collections.Hashtable hints)
{
bool tryHarder = hints != null && hints.ContainsKey(DecodeHintType.TRY_HARDER);
int maxI = image.Height;
int maxJ = image.Width;
// We are looking for black/white/black/white/black modules in
// 1:1:3:1:1 ratio; this tracks the number of such modules seen so far
// Let's assume that the maximum version QR Code we support takes up 1/4 the height of the
// image, and then account for the center being 3 modules in size. This gives the smallest
// number of pixels the center could be, so skip this often. When trying harder, look for all
// QR versions regardless of how dense they are.
int iSkip = (3 * maxI) / (4 * MAX_MODULES);
if (iSkip < MIN_SKIP || tryHarder)
{
iSkip = MIN_SKIP;
}
bool done = false;
int[] stateCount = new int[5];
for (int i = iSkip - 1; i < maxI && !done; i += iSkip)
{
// Get a row of black/white values
stateCount[0] = 0; // black
stateCount[1] = 0; // white
stateCount[2] = 0; // black
stateCount[3] = 0; // white
stateCount[4] = 0; // black
int currentState = 0;
for (int j = 0; j < maxJ; j++)
{
if (image.get_Renamed(j, i))
{
// Black pixel
if ((currentState % 2) == 1) // if currentState is White (i.e. 1 or 3)
{
// Counting white pixels
currentState++;
}
stateCount[currentState]++;
}
else
{
// White pixel
if ((currentState % 2) == 0)
{
// Counting black pixels
if (currentState == 4)
{
// A winner?
if (foundPatternCross(stateCount))
{
// Yes
bool confirmed = handlePossibleCenter(stateCount, i, j);
if (confirmed)
{
// Start examining every other line. Checking each line turned out to be too
// expensive and didn't improve performance.
iSkip = 2;
if (hasSkipped)
{
done = haveMultiplyConfirmedCenters();
}
else
{
int rowSkip = findRowSkip();
if (rowSkip > stateCount[2])
{
// Skip rows between row of lower confirmed center
// and top of presumed third confirmed center
// but back up a bit to get a full chance of detecting
// it, entire width of center of finder pattern
// Skip by rowSkip, but back off by stateCount[2] (size of last center
// of pattern we saw) to be conservative, and also back off by iSkip which
// is about to be re-added
i += rowSkip - stateCount[2] - iSkip;
j = maxJ - 1;
}
}
}
else
{
// Advance to next black pixel
do
{
j++;
}while (j < maxJ && !image.get_Renamed(j, i));
j--; // back up to that last white pixel
}
// Clear state to start looking again
currentState = 0;
stateCount[0] = 0;
stateCount[1] = 0;
stateCount[2] = 0;
stateCount[3] = 0;
stateCount[4] = 0;
}
else
{
// No, shift counts back by two
stateCount[0] = stateCount[2];
stateCount[1] = stateCount[3];
stateCount[2] = stateCount[4];
stateCount[3] = 1;
stateCount[4] = 0;
currentState = 3;
}
}
else
{
stateCount[++currentState]++;
}
}
else
{
// Counting white pixels
stateCount[currentState]++;
}
}
}
if (foundPatternCross(stateCount))
{
bool confirmed = handlePossibleCenter(stateCount, i, maxJ);
if (confirmed)
{
iSkip = stateCount[0];
if (hasSkipped)
{
// Found a third one
done = haveMultiplyConfirmedCenters();
}
}
}
}
FinderPattern[] patternInfo = selectBestPatterns();
if (patternInfo.IsBlank())
{
return(null);
}
ResultPoint.orderBestPatterns(patternInfo);
return(new FinderPatternInfo(patternInfo));
}
public FinderPatternInfo[] findMulti(System.Collections.Hashtable hints)
{
bool tryHarder = hints != null && hints.ContainsKey(DecodeHintType.TRY_HARDER);
BitMatrix image = Image;
int maxI = image.Height;
int maxJ = image.Width;
// We are looking for black/white/black/white/black modules in
// 1:1:3:1:1 ratio; this tracks the number of such modules seen so far
// Let's assume that the maximum version QR Code we support takes up 1/4 the height of the
// image, and then account for the center being 3 modules in size. This gives the smallest
// number of pixels the center could be, so skip this often. When trying harder, look for all
// QR versions regardless of how dense they are.
//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 iSkip = (int)(maxI / (MAX_MODULES * 4.0f) * 3);
if (iSkip < MIN_SKIP || tryHarder)
{
iSkip = MIN_SKIP;
}
int[] stateCount = new int[5];
for (int i = iSkip - 1; i < maxI; i += iSkip)
{
// Get a row of black/white values
stateCount[0] = 0;
stateCount[1] = 0;
stateCount[2] = 0;
stateCount[3] = 0;
stateCount[4] = 0;
int currentState = 0;
for (int j = 0; j < maxJ; j++)
{
if (image.get_Renamed(j, i))
{
// Black pixel
if ((currentState & 1) == 1)
{
// Counting white pixels
currentState++;
}
stateCount[currentState]++;
}
else
{
// White pixel
if ((currentState & 1) == 0)
{
// Counting black pixels
if (currentState == 4)
{
// A winner?
if (foundPatternCross(stateCount))
{
// Yes
bool confirmed = handlePossibleCenter(stateCount, i, j);
if (!confirmed)
{
do
{
// Advance to next black pixel
j++;
}while (j < maxJ && !image.get_Renamed(j, i));
j--; // back up to that last white pixel
}
// Clear state to start looking again
currentState = 0;
stateCount[0] = 0;
stateCount[1] = 0;
stateCount[2] = 0;
stateCount[3] = 0;
stateCount[4] = 0;
}
else
{
// No, shift counts back by two
stateCount[0] = stateCount[2];
stateCount[1] = stateCount[3];
stateCount[2] = stateCount[4];
stateCount[3] = 1;
stateCount[4] = 0;
currentState = 3;
}
}
else
{
stateCount[++currentState]++;
}
}
else
{
// Counting white pixels
stateCount[currentState]++;
}
}
} // for j=...
if (foundPatternCross(stateCount))
{
handlePossibleCenter(stateCount, i, maxJ);
} // end if foundPatternCross
} // for i=iSkip-1 ...
FinderPattern[][] patternInfo = selectBestPatterns();
System.Collections.ArrayList result = System.Collections.ArrayList.Synchronized(new System.Collections.ArrayList(10));
for (int i = 0; i < patternInfo.Length; i++)
{
FinderPattern[] pattern = patternInfo[i];
ResultPoint.orderBestPatterns(pattern);
result.Add(new FinderPatternInfo(pattern));
}
if ((result.Count == 0))
{
return(EMPTY_RESULT_ARRAY);
}
else
{
FinderPatternInfo[] resultArray = new FinderPatternInfo[result.Count];
for (int i = 0; i < result.Count; i++)
{
resultArray[i] = (FinderPatternInfo)result[i];
}
return(resultArray);
}
}