Beispiel #1
0
  public static Image houghLineDetector(Image original, double epsilon, double threshold) {
    // Apply border detector
    Image borderImage =
        MaskUtils.applyMasks(original, MaskFactory.buildSobelMasks(), SynthetizationType.ABS);
    borderImage = ThresholdUtils.global(borderImage, Image.MAX_VAL / 2, 1);

    double D = Math.max(borderImage.getWidth(), borderImage.getHeight());
    Range roRange = new Range(-Math.sqrt(2) * D, Math.sqrt(2) * D);
    Range thetaRange = new Range(-90, 90);
    int roSize = (int) (Math.abs(roRange.getLength()));
    int thetaSize = (int) (Math.abs(thetaRange.getLength()));
    int[][] A = new int[roSize][thetaSize];

    // Step 3
    for (int x = 0; x < borderImage.getWidth(); x++) {
      for (int y = 0; y < borderImage.getHeight(); y++) {
        if (isWhite(borderImage, x, y)) {
          // Iterates theta (j) from 1 to m
          for (int theta = 0; theta < thetaSize; theta++) {
            double thetaValue = thetaRange.getLowerBound() + theta;
            double thetaTerm =
                x * Math.cos(thetaValue * Math.PI / 180) - y * Math.sin(thetaValue * Math.PI / 180);

            // Iterates ro (i) from 1 to n
            for (int ro = 0; ro < roSize; ro++) {
              double roValue = roRange.getLowerBound() + ro;
              double total = roValue - thetaTerm;
              // If verifies the normal equation of the line, add
              // 1 to the acumulator
              // Step 4
              if (Math.abs(total) < epsilon) {
                // The maximum values from this vector, gives
                // the most voted positions.
                A[ro][theta] += 1;
              }
            }
          }
        }
      }
    }

    // Step 5
    Set<BucketForLines> allBuckets = new HashSet<BucketForLines>();
    for (int ro = 0; ro < roSize; ro++) {
      for (int theta = 0; theta < thetaSize; theta++) {
        BucketForLines newBucket = new BucketForLines(ro, theta, A[ro][theta]);
        allBuckets.add(newBucket);
      }
    }

    // Generates a descending sorted list.
    List<BucketForLines> allBucketsAsList = new ArrayList<BucketForLines>(allBuckets);
    Collections.sort(allBucketsAsList);

    Image houghed = original.clone();
    // Gets the max vote number
    int maxVotes = allBucketsAsList.get(0).votes;
    if (maxVotes > 1) {
      for (BucketForLines b : allBucketsAsList) {

        // Only for those with max votes
        if (b.votes < maxVotes * threshold) {
          break;
        }

        double roValue = roRange.getLowerBound() + b.ro;
        double thetaValue = thetaRange.getLowerBound() + b.theta;

        for (int x = 0; x < borderImage.getWidth(); x++) {
          for (int y = 0; y < borderImage.getHeight(); y++) {
            double thetaTerm =
                x * Math.cos(thetaValue * Math.PI / 180) - y * Math.sin(thetaValue * Math.PI / 180);
            double total = roValue - thetaTerm;
            // Step 6
            if (Math.abs(total) < epsilon) {
              paintRed(houghed, x, y);
            }
          }
        }
      }
    }

    return houghed;
  }
Beispiel #2
0
  public static Image houghCircleDetector(
      Image original, double epsilon, double threshold, int rMin, int rMax) {
    // Apply border detector
    Image borderImage =
        MaskUtils.applyMasks(original, MaskFactory.buildSobelMasks(), SynthetizationType.ABS);
    borderImage = ThresholdUtils.global(borderImage, Image.MAX_VAL / 2, 1);

    Range aRange = new Range(rMin, borderImage.getWidth() - rMin);
    Range bRange = new Range(rMin, borderImage.getHeight() - rMin);
    Range rRange = new Range(rMin, rMax);

    int aSize = (int) (Math.abs(aRange.getLength()));
    int bSize = (int) (Math.abs(bRange.getLength()));
    int rSize = (int) (Math.abs(rRange.getLength()));
    int[][][] A = new int[aSize][bSize][rSize];

    for (int r = 0; r < rSize; r += 2) {
      double rValue = rRange.getLowerBound() + r;
      double rTerm = Math.pow(rValue, 2);
      for (int a = 0; a < aSize; a += 2) {
        double aValue = aRange.getLowerBound() + a;
        for (int b = 0; b < bSize; b += 2) {
          double bValue = bRange.getLowerBound() + b;
          for (int x = 0; x < borderImage.getWidth(); x += 2) {
            double aTerm = Math.pow(x - aValue, 2);
            for (int y = 0; y < borderImage.getHeight(); y += 2) {
              if (isWhite(borderImage, x, y)) {
                double bTerm = Math.pow(y - bValue, 2);
                double total = rTerm - aTerm - bTerm;
                if (Math.abs(total) < epsilon) {
                  A[a][b][r] += 1;
                }
              }
            }
          }
        }
      }
    }

    System.out.println("Voted");

    Set<BucketForCircles> allBuckets = new HashSet<BucketForCircles>();
    for (int a = 0; a < aSize; a += 2) {
      for (int b = 0; b < bSize; b += 2) {
        for (int r = 0; r < rSize; r += 2) {
          if (A[a][b][r] > 0) {
            BucketForCircles newBucket = new BucketForCircles(a, b, r, A[a][b][r]);
            allBuckets.add(newBucket);
          }
        }
      }
    }
    Image houghed = original.clone();
    if (allBuckets.isEmpty()) {
      System.out.println("Empty Buckets");
      return houghed;
    }

    List<BucketForCircles> allBucketsAsList = new ArrayList<BucketForCircles>(allBuckets);
    Collections.sort(allBucketsAsList);

    int maxHits = allBucketsAsList.get(0).votes;

    System.out.println("maxHits:" + maxHits);

    if (maxHits > 2)
      for (BucketForCircles b : allBucketsAsList) {
        if (b.votes < maxHits * threshold) {
          break;
        }

        int aValue = rMin + b.a;

        int bValue = (int) bRange.getLowerBound() + b.b;
        int rValue = (int) rRange.getLowerBound() + b.r;

        System.out.println("Circle: (" + aValue + "," + bValue + "," + rValue + ")");

        drawCircle(houghed, aValue, bValue, rValue);
      }

    return houghed;
  }