c++ - OpenCV - 匹配 SURF 点运行时错误

Question

我有一个程序可以将模板图像中找到的特征点与视频源中显示的特征点相匹配。当我运行该程序时，出现以下错误:

OpenCV Error: Assertion failed (i1 >= 0 && i1 < static_cast<int>(keypoints1.size())) in drawMatches, file bin/opencv-2.4.7/modules/features2d/src/draw.cpp, line 207
terminate called after throwing an instance of 'cv::Exception'
  what():  bin/opencv-2.4.7/modules/features2d/src/draw.cpp:207: error: (-215) i1 >= 0 && i1 < static_cast<int>(keypoints1.size()) in function drawMatches

Aborted

这就是上面提到的函数drawMatches:

drawMatches(img_1, templateKeypoints, frames, keypoints_1, good_matches, img_matches, cv::Scalar::all(-1), cv::Scalar::all(-1), std::vector<char>(), cv::DrawMatchesFlags::NOT_DRAW_SINGLE_POINTS);

根据我的阅读，我认为问题在于如果视频中发现的特征点与模板图像中的特征点不匹配，那么程序就会中止。

min_dist = 100;      
for(int i = 0; i < img_descriptors_1.rows; i++) {
        if(matches[i].distance <= 3 * min_dist) {
          good_matches.push_back(matches[i]);
        }
      }

我正在寻找即使不存在匹配项也能持续运行的视频源。

编辑:

我注意到，如果我反复尝试运行该程序，我有时会收到一条替代错误消息:

OpenCV Error: Assertion failed (npoints >= 0 && points2.checkVector(2) == npoints && points1.type() == points2.type()) in findHomography, file /home/colin/bin/opencv-2.4.7/modules/calib3d/src/fundam.cpp, line 1074
terminate called after throwing an instance of 'cv::Exception'
  what():  /home/colin/bin/opencv-2.4.7/modules/calib3d/src/fundam.cpp:1074: error: (-215) npoints >= 0 && points2.checkVector(2) == npoints && points1.type() == points2.type() in function findHomography

Aborted

Answer 1

紧接以下内容:

extractor.compute(img_1, keypoints_1, descriptors_1);
extractor.compute(frame, keypoints_2, descriptors_2);

请添加:

if ((descriptors_1.empty()) || (descriptors_2.empty()))
continue;

由于在特定帧中没有找到关键点，它应该进入下一次迭代并检查新帧。 这解决了我的问题。