OpenCV 错误的解决方案:不支持的格式或格式组合 - 当将 ORB 功能与 FlannBasedMatcher 匹配

我试图使用 ORB.My 代码找到好的匹配如下：

Ptr<FeatureDetector> detector = ORB::create();
Mat descriptors_img1, descriptors_img2;

//-- Step 2: Calculate descriptors (feature vectors)
detector->detect(img1, kp1,descriptors_img1);
detector->detect(img2, kp2,descriptors_img2);

Ptr<DescriptorExtractor> extractor = ORB::create();
extractor->compute(img1, kp1, descriptors_img1 );
extractor->compute(img2, kp2, descriptors_img2 );
//-- Step 3: Matching descriptor vectors using FLANN matcher
descriptors_img1.convertTo(descriptors_img1, CV_32F);
descriptors_img2.convertTo(descriptors_img2, CV_32F);
FlannBasedMatcher matcher;
std::vector<DMatch> matches;
matcher.match(descriptors_img1,descriptors_img2,matches);
double max_dist = 0; double min_dist = 100;
//-- Quick calculation of max and min distances between keypoints
for( int i = 0; i < descriptors_img1.rows; i++ )
{
double dist = matches[i].distance;
if( dist < min_dist )
min_dist = dist;
if( dist > max_dist )
max_dist = dist;
}
printf("-- Max dist : %f n", max_dist );
printf("-- Min dist : %f n", min_dist );
//-- Draw only "good" matches (i.e. whose distance is less than 3*min_dist )
std::vector< DMatch > good_matches;
for( int i = 0; i < descriptors_img1.rows; i++ )
{
if( matches[i].distance < 3*min_dist )
{
good_matches.push_back( matches[i]);
}
}
Mat img_matches;
drawMatches(img1,kp1,img2,kp2,good_matches,img_matches,Scalar::all(-1),
Scalar::all(-1),vector<char>(),DrawMatchesFlags::NOT_DRAW_SINGLE_POINTS );
//-- Show detected matches
imshow( "Good Matches", img_matches );

但是当我运行它时，我收到错误说：

OpenCV 错误：不支持的格式或格式组合(类型 = 0 ( 在 buildIndex_ 中，文件/home/openCV-3.2.0/modules/flann/src/miniflann.cpp，第 315 行 在抛出"cv：：异常"实例后终止调用 what((：/home/opencv-3.2.0/modules/flann/src/miniflann.cpp：315：函数buildIndex_中的错误：(-210( type=0

我看了类似的问题，但没有找到答案。调试后，我开始知道错误在

matcher.match(....);

请帮助我解决这个问题。提前致谢