[英]OpenCV Sift/Surf/Orb : drawMatch function is not working well
我使用Sift / Surf和ORB,但有時我的drawMatch函數有問題。
這里的錯誤:
OpenCV錯誤:斷言失敗(i2> = 0 && i2 <static_cast(keypoints2.size()))在drawMatches中,文件/home/opencv-2.4.6.1/modules/features2d/src/draw.cpp,第208行終止后調用拋出'cv :: Exception'的實例what():/ home / opencv-2.4.6.1 / modules / features2d / src / draw.cpp:208:error:( - 1515)i2> = 0 && i2 <static_cast( keyPoint2.size())在函數drawMatche中
代碼 :
drawMatchPoints(img1,keypoints_img1,img2,keypoints_img2,matches);
我嘗試將img 1,keypoints_img1與img2和keypoints_img2反轉為:
drawMatchPoints(img2,keypoints_img2,img1,keypoints_img1,matches);
對應我正在做單應性的功能:
void drawMatchPoints(cv::Mat image1,std::vector<KeyPoint> keypoints_img1,
cv::Mat image2,std::vector<KeyPoint> keypoints_img2,std::vector<cv::DMatch> matches){
cv::Mat img_matches;
drawMatches( image1, keypoints_img1, image2, keypoints_img2,
matches, img_matches, Scalar::all(-1), Scalar::all(-1),
vector<char>(), DrawMatchesFlags::NOT_DRAW_SINGLE_POINTS );
std::cout << "Number of good matching " << (int)matches.size() << "\n" << endl;
//-- Localize the object
std::vector<Point2f> obj;
std::vector<Point2f> scene;
for( int i = 0; i < matches.size(); i++ )
{
//-- Get the keypoints from the good matches
obj.push_back( keypoints_img1[ matches[i].queryIdx ].pt );
scene.push_back( keypoints_img2[matches[i].trainIdx ].pt );
}
Mat H = findHomography( obj, scene, CV_RANSAC );
std::cout << "Size of homography " << *H.size << std::endl ;
//-- Get the corners from the image_1 ( the object to be "detected" )
std::vector<Point2f> obj_corners(4);
obj_corners[0] = cvPoint(0,0); obj_corners[1] = cvPoint( image1.cols, 0 );
obj_corners[2] = cvPoint( image1.cols, image1.rows ); obj_corners[3] = cvPoint( 0, image1.rows );
std::vector<Point2f> scene_corners(4);
perspectiveTransform( obj_corners, scene_corners, H);
//-- Draw lines between the corners (the mapped object in the scene - image_2 )
line( img_matches, scene_corners[0] + Point2f( image1.cols, 0), scene_corners[1] + Point2f( image1.cols, 0), Scalar(0, 255, 0), 4 );
line( img_matches, scene_corners[1] + Point2f( image1.cols, 0), scene_corners[2] + Point2f( image1.cols, 0), Scalar( 0, 255, 0), 4 );
line( img_matches, scene_corners[2] + Point2f( image1.cols, 0), scene_corners[3] + Point2f( image1.cols, 0), Scalar( 0, 255, 0), 4 );
line( img_matches, scene_corners[3] + Point2f( image1.cols, 0), scene_corners[0] + Point2f( image1.cols, 0), Scalar( 0, 255, 0), 4 );
//-- Show detected matches
cv::imshow( "Good Matches & Object detection", img_matches );
cv::waitKey(5000);
}
但我仍然有錯誤!
我注意到當我的keypoints_img1的大小低於我的keypoints_img2的大小時發生了錯誤:
大小keyPoint1:244 - 大小keyPoint2:400
因此,如果我反轉我的兩張照片的加載,這是有效的,但我現在不能提前,如果我的第一張照片將有更多的關鍵點,我的第二張照片......
我的代碼(最重要的一步)是為了創建功能:
init_Sift(400,5,0.04,25,1.6);
void init_Sift(int nf,int nOctaveL,double contrastThresh, double edgeThresh,double sigma){
this->nfeatureSift=nf;
this->nOctaveLayerSift=nOctaveL;
this->contrastThresholdSift=contrastThresh;
this->edgeThresholdSift=edgeThresh;
this->sigmaSift=sigma;}
cv::FeatureDetector* detector=new SiftFeatureDetector(nfeatureSift,nOctaveLayerSift,contrastThresholdSift,edgeThresholdSift,sigmaSift);
cv::DescriptorExtractor* extractor=new SiftDescriptorExtractor
extractor->compute( image, keypoints, descriptors );
匹配部分:
std::cout << "Type of matcher : " << type_of_matcher << std::endl;
if (type_of_matcher=="FLANN" || type_of_matcher=="BF"){
std::vector<KeyPoint> keypoints_img1 = keyfeatures.compute_Keypoints(img1);
std::vector<KeyPoint> keypoints_img2 = keyfeatures.compute_Keypoints(img2);
cv::Mat descriptor_img1 = keyfeatures.compute_Descriptors(img1);
cv::Mat descriptor_img2 = keyfeatures.compute_Descriptors(img2);
std::cout << "Size keyPoint1 " << keypoints_img1.size() << "\n" << std::endl;
std::cout << "Size keyPoint2 " << keypoints_img2.size() << "\n" << std::endl;
//Flann with sift or surf
if (type_of_matcher=="FLANN"){
Debug::info("USING Matcher FLANN");
fLmatcher.match(descriptor_img1,descriptor_img2,matches);
double max_dist = 0; double min_dist = 100;
//-- Quick calculation of max and min distances between keypoints
for( int i = 0; i < descriptor_img1.rows; i++ ){
double dist = matches[i].distance;
if( dist < min_dist ) min_dist = dist;
if( dist > max_dist ) max_dist = dist;
}
std::vector< DMatch > good_matches;
for( int i = 0; i < descriptor_img1.rows; i++ )
{ if( matches[i].distance <= max(2*min_dist, 0.02) )
{ good_matches.push_back( matches[i]); }
}
std::cout << "Size of good match : " << (int)good_matches.size() << std::endl;
//-- Draw only "good" matches
if (!good_matches.empty()){
drawMatchPoints(img1,keypoints_img1,img2,keypoints_img2,good_matches);
}
else {
Debug::error("Flann Matcher : Pas de match");
cv::Mat img_matches;
drawMatches( img1, keypoints_img1, img2, keypoints_img2,
matches, img_matches, Scalar::all(-1), Scalar::all(-1),
vector<char>(), DrawMatchesFlags::NOT_DRAW_SINGLE_POINTS );
cv::imshow( "No match", img_matches );
cv::waitKey(5000);
}
}
//BruteForce with sift or surf
else if (type_of_matcher=="BF"){
Debug::info("USING Matcher Brute Force");
bFmatcher.match(descriptor_img1,descriptor_img2,matches);
if (!matches.empty()){
std::nth_element(matches.begin(),//Initial position
matches.begin()+24, //Position of the sorted element
matches.end());//End position
matches.erase(matches.begin()+25,matches.end());
drawMatchPoints(img1,keypoints_img1,img2,keypoints_img2,matches);
//drawMatchPoints(img2,keypoints_img2,img1,keypoints_img1,matches);
}
else {
Debug::error("Brute Force matcher : Pas de match");
cv::Mat img_matches;
drawMatches( img1, keypoints_img1, img2, keypoints_img2,
matches, img_matches, Scalar::all(-1), Scalar::all(-1),
vector<char>(), DrawMatchesFlags::NOT_DRAW_SINGLE_POINTS );
cv::imshow( "No match", img_matches );
cv::waitKey(5000);
}
}
你有什么建議或建議嗎?
編輯:我解決了我的問題。 我有一個c ++問題,因為我有兩個班級。 一個關於匹配,另一個關於查找keyFeature。 我已經寫了我的.h std :: vector和描述符相同。
class keyFeatures{
public:
...
std::vector<keyPoint> keypoints;
...
我刪除了這個屬性,我做了一個函數,它接受參數std :: vector keypoints
cv::Mat descriptor_img1 = keyfeatures.compute_Descriptors(img1,keypoints_img1);
代替
cv::Mat descriptor_img1 = keyfeatures.compute_Descriptors(img1);
我認為當我進行匹配時存在沖突...但我不知道為什么我不應該在我的.h上寫它並在我的函數上做一個局部參數。
謝謝 !
對於像我這樣尋找此但卻無法找到解決方案的人。
斷言失敗(i2> = 0 && i2 <static_cast(keypoints2.size()))
這意味着由於i2小於0或i2小於keypoints2大小,斷言失敗。 但是i2是什么?
來自rbaleksandar在評論中提供的鏈接
int i2 = matches1to2 [m] .trainIdx;
trainIdx這里是keypoints2中的索引。 檢查i2 <static_cast(keypoints2.size())確保索引小於keypoints2.size()。
對我來說,它發生了,因為我在調用drawMatches之前丟棄了一些關鍵點,但在計算了描述符之后,即調用了DescriptorExtractor#compute。 這意味着當我更改這些關鍵點時,drawMatches通過描述符引用舊關鍵點。 最終結果是一些關鍵點具有大的idx但關鍵點大小很小因此錯誤。
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