first-time-FlannBasedMatcher会影响后续FlannBasedMatcher的结果

Question

我在我的项目中使用了两次FlannBasedMatcher，但是第一个FlannBasedMatcher似乎影响了第二个FlannBasedMatcher的结果。

cvtColor(c_image1,hsi1,CV_BGR2HSV);
cvtColor(c_image2,hsi2,CV_BGR2HSV);
split(hsi1,channel_hsi1);
split(hsi2,channel_hsi2);
image1s=channel_hsi1[1];
image2s=channel_hsi2[1];
cvtColor(c_image1,image1,CV_RGB2GRAY);
cvtColor(c_image2,image2,CV_RGB2GRAY); 
SiftFeatureDetector detector(800);
SiftDescriptorExtractor extractor;
FlannBasedMatcher matcher;   

//第一个匹配

vector<KeyPoint>keypoint1,keypoint2;
detector.detect(image1,keypoint1);
detector.detect(image2,keypoint2);
Mat des1,des2;
extractor.compute(image1,keypoint1,des1);
extractor.compute(image2,keypoint2,des2);
vector<DMatch>matchpoints_i;
**matcher.match(des1,des2,matchpoints_i);//this line,if I delete it,the result of matchpoints_s will be right.But if I reserve it,the match condition of matchpoints_s will be bad,and even matchpoints_s[i].distance changed a lot.**
sort(matchpoints_i.begin(),matchpoints_i.end());

//第二场比赛

vector<KeyPoint>keypoint1s,keypoint2s;
detector.detect(image1s,keypoint1s);
detector.detect(image2s,keypoint2s);
Mat des1s,des2s;
extractor.compute(image1s,keypoint1s,des1s);
extractor.compute(image2s,keypoint2s,des2s);
vector<DMatch>matchpoints_s;
matcher.match(des1s,des2s,matchpoints_s);
sort(matchpoints_s.begin(),matchpoints_s.end());
for(size_t i=0;i<matchpoints_s.size();i++)
    { 
        cout<< matchpoints_s[i].distance<<endl;
   }

reserve the line,bad result

delete the line,good result

当我使用FlannBasedMatcher两次时，是否会发生冲突？

Answer 1

当然，不应该有任何冲突。确保你检查输入--特别是我担心，通过HSV图像的S通道来检测特征是一个好主意：

 image1s=channel_hsi1[1];
 image2s=channel_hsi2[1];

也许H-channel会更好：

 image1s=channel_hsi1[0];
 image2s=channel_hsi2[0];

附注:我已经仔细检查了我的工作代码--是的，在你使用其他图像集之前，你必须调用matcher.clear()。