在iOS中打开CV SurfFeatureDetection

Question

我指的是OpenCV on iOS: False matching with SurfFeatureDetector and FlannBasedMatcher

尝试实现我自己的功能，稍作修改： -

+ (void)checkImageWorks: (UIImage *)inputImage mainImageView:    (UIImageView *)mainImageView{
  UIImage *sceneImage, *objectImage1;
  cv::Mat sceneImageMat, objectImageMat1;
  cv::vector<cv::KeyPoint> sceneKeypoints, objectKeypoints1;
  cv::Mat sceneDescriptors, objectDescriptors1;
  cv::SurfFeatureDetector *surfDetector;
  cv::SurfDescriptorExtractor surfExtractor;
  cv::FlannBasedMatcher flannMatcher;
  cv::vector<cv::DMatch> matches;
  int minHessian;
  double minDistMultiplier;

  minHessian = 400;
  minDistMultiplier= 3;
  surfDetector = new cv::SurfFeatureDetector(minHessian);

  sceneImage = inputImage;

  objectImage1 = [UIImage imageNamed:@"small.png"];

  sceneImageMat = cv::Mat(sceneImage.size.height, sceneImage.size.width, CV_8UC1);
  objectImageMat1 = cv::Mat(objectImage1.size.height, objectImage1.size.width, CV_8UC1);

  cv::cvtColor([sceneImage CVMat], sceneImageMat, CV_RGB2GRAY);
  cv::cvtColor([objectImage1 CVMat], objectImageMat1, CV_RGB2GRAY);

  if (!sceneImageMat.data || !objectImageMat1.data) {
    NSLog(@"NO DATA");
  }

  surfDetector->detect(sceneImageMat, sceneKeypoints);
  surfDetector->detect(objectImageMat1, objectKeypoints1);

  surfExtractor.compute(sceneImageMat, sceneKeypoints, sceneDescriptors);
  surfExtractor.compute(objectImageMat1, objectKeypoints1, objectDescriptors1);

  flannMatcher.match(objectDescriptors1, sceneDescriptors, matches);

  double max_dist = 0; double min_dist = 100;

  for( int i = 0; i < objectDescriptors1.rows; i++ )
  {
    double dist = matches[i].distance;
    if( dist < min_dist ) min_dist = dist;
    if( dist > max_dist ) max_dist = dist;
  }

  cv::vector<cv::DMatch> goodMatches;
  for( int i = 0; i < objectDescriptors1.rows; i++ )
  {
    if( matches[i].distance < minDistMultiplier*min_dist )
    {
      goodMatches.push_back( matches[i]);
    }
  }
  NSLog(@"Good matches found: %lu", goodMatches.size());

  cv::Mat imageMatches;
  cv::drawMatches(objectImageMat1, objectKeypoints1, sceneImageMat, sceneKeypoints, goodMatches, imageMatches, cv::Scalar::all(-1), cv::Scalar::all(-1),
                  cv::vector<char>(), cv::DrawMatchesFlags::NOT_DRAW_SINGLE_POINTS);

  std::vector<cv::Point2f> obj;
  std::vector<cv::Point2f> scn;

  for( int i = 0; i < goodMatches.size(); i++ )
  {
    //-- Get the keypoints from the good matches
    obj.push_back( objectKeypoints1[ goodMatches[i].queryIdx ].pt );
    scn.push_back( sceneKeypoints[ goodMatches[i].trainIdx ].pt );
  }

  cv::vector<uchar> outputMask;
  cv::Mat homography = cv::findHomography(obj, scn, CV_RANSAC, 3, outputMask);
  int inlierCounter = 0;
  for (int i = 0; i < outputMask.size(); i++) {
    if (outputMask[i] == 1) {
      inlierCounter++;
    }
  }
  NSLog(@"Inliers percentage: %d", (int)(((float)inlierCounter / (float)outputMask.size()) * 100));

  cv::vector<cv::Point2f> objCorners(4);
  objCorners[0] = cv::Point(0,0);
  objCorners[1] = cv::Point( objectImageMat1.cols, 0 );
  objCorners[2] = cv::Point( objectImageMat1.cols, objectImageMat1.rows );
  objCorners[3] = cv::Point( 0, objectImageMat1.rows );

  cv::vector<cv::Point2f> scnCorners(4);

  cv::perspectiveTransform(objCorners, scnCorners, homography);

  cv::line( imageMatches, scnCorners[0] + cv::Point2f( objectImageMat1.cols, 0), scnCorners[1] + cv::Point2f( objectImageMat1.cols, 0), cv::Scalar(0, 255, 0), 4);
  cv::line( imageMatches, scnCorners[1] + cv::Point2f( objectImageMat1.cols, 0), scnCorners[2] + cv::Point2f( objectImageMat1.cols, 0), cv::Scalar( 0, 255, 0), 4);
  cv::line( imageMatches, scnCorners[2] + cv::Point2f( objectImageMat1.cols, 0), scnCorners[3] + cv::Point2f( objectImageMat1.cols, 0), cv::Scalar( 0, 255, 0), 4);
  cv::line( imageMatches, scnCorners[3] + cv::Point2f( objectImageMat1.cols, 0), scnCorners[0] + cv::Point2f( objectImageMat1.cols, 0), cv::Scalar( 0, 255, 0), 4);

  [mainImageView setImage:[UIImage imageWithCVMat:imageMatches]];
}

但它给我一个错误： -

libc++abi.dylib: terminating with uncaught exception of type cv::Exception: /Users/alexandershishkov/dev/opencv2.4.9/opencv/modules/calib3d/src/fundam.cpp:1074: error: (-215) npoints >= 0 && points2.checkVector(2) == npoints && points1.type() == points2.type() in function findHomography

请帮帮我！