/// <returns> true iff we have found at least 3 finder patterns that have been detected /// at least {@link #CENTER_QUORUM} times each, and, the estimated module size of the /// candidates is "pretty similar" /// </returns> private bool haveMultiplyConfirmedCenters() { int confirmedCount = 0; float totalModuleSize = 0.0f; int max = possibleCenters.Count; for (int i = 0; i < max; i++) { FinderPattern pattern = (FinderPattern)possibleCenters[i]; if (pattern.Count >= CENTER_QUORUM) { confirmedCount++; totalModuleSize += pattern.EstimatedModuleSize; } } if (confirmedCount < 3) { return(false); } // OK, we have at least 3 confirmed centers, but, it's possible that one is a "false positive" // and that we need to keep looking. We detect this by asking if the estimated module sizes // vary too much. We arbitrarily say that when the total deviation from average exceeds // 5% of the total module size estimates, it's too much. //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 average = totalModuleSize / (float)max; float totalDeviation = 0.0f; for (int i = 0; i < max; i++) { FinderPattern pattern = (FinderPattern)possibleCenters[i]; totalDeviation += System.Math.Abs(pattern.EstimatedModuleSize - average); } return(totalDeviation <= 0.05f * totalModuleSize); }
/// <returns> number of rows we could safely skip during scanning, based on the first /// two finder patterns that have been located. In some cases their position will /// allow us to infer that the third pattern must lie below a certain point farther /// down in the image. /// </returns> private int findRowSkip() { int max = possibleCenters.Count; if (max <= 1) { return(0); } FinderPattern firstConfirmedCenter = null; for (int i = 0; i < max; i++) { FinderPattern center = (FinderPattern)possibleCenters[i]; if (center.Count >= CENTER_QUORUM) { if (firstConfirmedCenter == null) { firstConfirmedCenter = center; } else { // We have two confirmed centers // How far down can we skip before resuming looking for the next // pattern? In the worst case, only the difference between the // difference in the x / y coordinates of the two centers. // This is the case where you find top left last. hasSkipped = true; //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'" return((int)(System.Math.Abs(firstConfirmedCenter.X - center.X) - System.Math.Abs(firstConfirmedCenter.Y - center.Y)) / 2); } } } return(0); }
/// <summary> <p>This is called when a horizontal scan finds a possible alignment pattern. It will /// cross check with a vertical scan, and if successful, will, ah, cross-cross-check /// with another horizontal scan. This is needed primarily to locate the real horizontal /// center of the pattern in cases of extreme skew.</p> /// /// <p>If that succeeds the finder pattern location is added to a list that tracks /// the number of times each location has been nearly-matched as a finder pattern. /// Each additional find is more evidence that the location is in fact a finder /// pattern center /// /// </summary> /// <param name="stateCount">reading state module counts from horizontal scan /// </param> /// <param name="i">row where finder pattern may be found /// </param> /// <param name="j">end of possible finder pattern in row /// </param> /// <returns> true if a finder pattern candidate was found this time /// </returns> protected internal virtual bool handlePossibleCenter(int[] stateCount, int i, int j) { int stateCountTotal = stateCount[0] + stateCount[1] + stateCount[2] + stateCount[3] + stateCount[4]; float centerJ = centerFromEnd(stateCount, j); //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 centerI = crossCheckVertical(i, (int)centerJ, stateCount[2], stateCountTotal); if (!System.Single.IsNaN(centerI)) { // Re-cross check //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'" centerJ = crossCheckHorizontal((int)centerJ, (int)centerI, stateCount[2], stateCountTotal); if (!System.Single.IsNaN(centerJ)) { //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 estimatedModuleSize = (float)stateCountTotal / 7.0f; bool found = false; int max = possibleCenters.Count; for (int index = 0; index < max; index++) { FinderPattern center = (FinderPattern)possibleCenters[index]; // Look for about the same center and module size: if (center.aboutEquals(estimatedModuleSize, centerI, centerJ)) { center.incrementCount(); found = true; break; } } if (!found) { ResultPoint point = new FinderPattern(centerJ, centerI, estimatedModuleSize); possibleCenters.Add(point); if (resultPointCallback != null) { resultPointCallback.foundPossibleResultPoint(point); } } return(true); } } return(false); }
/// <returns> the 3 best {@link FinderPattern}s from our list of candidates. The "best" are /// those that have been detected at least {@link #CENTER_QUORUM} times, and whose module /// size differs from the average among those patterns the least /// </returns> /// <throws> ReaderException if 3 such finder patterns do not exist </throws> private FinderPattern[] selectBestPatterns() { int startSize = possibleCenters.Count; if (startSize < 3) { // Couldn't find enough finder patterns throw ReaderException.Instance; } // Filter outlier possibilities whose module size is too different if (startSize > 3) { // But we can only afford to do so if we have at least 4 possibilities to choose from float totalModuleSize = 0.0f; for (int i = 0; i < startSize; i++) { totalModuleSize += ((FinderPattern)possibleCenters[i]).EstimatedModuleSize; } //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 average = totalModuleSize / (float)startSize; for (int i = 0; i < possibleCenters.Count && possibleCenters.Count > 3; i++) { FinderPattern pattern = (FinderPattern)possibleCenters[i]; if (System.Math.Abs(pattern.EstimatedModuleSize - average) > 0.2f * average) { possibleCenters.RemoveAt(i); i--; } } } if (possibleCenters.Count > 3) { // Throw away all but those first size candidate points we found. Collections.insertionSort(possibleCenters, new CenterComparator()); SupportClass.SetCapacity(possibleCenters, 3); } return(new FinderPattern[] { (FinderPattern)possibleCenters[0], (FinderPattern)possibleCenters[1], (FinderPattern)possibleCenters[2] }); }
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; PerspectiveTransform transform = createTransform(topLeft, topRight, bottomLeft, dimension); BitMatrix bits = sampleGrid(image, transform, dimension); ResultPoint[] points; points = new ResultPoint[] { bottomLeft, topLeft, topRight }; return(new DetectorResult(bits, points)); }
public FinderPatternInfo(FinderPattern[] patternCenters) { this.bottomLeft = patternCenters[0]; this.topLeft = patternCenters[1]; this.topRight = patternCenters[2]; }