Passende Vorlage imge (skaliert) auf Main/größeres Bild

Question

möchte ich finden/Check SubImage/Schablonenbild in Hauptbild und wollen seine Koordinaten wissen,

I-Code auf folgenden Link angegeben verwendet haben, sie umzusetzen,

Check presence of subimage in image in iOS

Es funktioniert gut, wenn die Größe des Schablonenbildes als Größe des passenden Teil eines größeren Bildes genau gleich ist.

Aber es gibt kein korrektes Ergebnis, wenn das Teilbild verkleinert oder hochskaliert wird, als Teil eines größeren Bildes.

Answer 1

Verwenden Sie OpenCV Feature Detection. es ist genauer als Template-Matching ..

Bitte versuchen Sie es mit diesem Code ..

-(void)featureDetection:(UIImage*)largerImage withImage:(UIImage*)subImage 
{ 
    cv::Mat tempMat1 = [largerImage CVMat]; 
    cv::Mat tempMat2 = [subImage CVMat]; 

    cv::cvtColor(tempMat1, tempMat1, CV_RGB2GRAY); 
    cv::cvtColor(tempMat2, tempMat2, CV_RGB2GRAY); 

    if(!tempMat1.data || !tempMat2.data) { 
     return; 
    } 

    //-- Step 1: Detect the keypoints using SURF Detector 
    int minHessian = 25; 

    cv::SurfFeatureDetector detector(minHessian); // More Accurate bt take more time.. 
    //cv::FastFeatureDetector detector(minHessian); //Less Accurate bt take less time.. 

    std::vector<cv::KeyPoint> keypoints_1, keypoints_2; 

    detector.detect(tempMat1, keypoints_1); 
    detector.detect(tempMat2, keypoints_2); 

    //-- Step 2: Calculate descriptors (feature vectors) 
    cv::SurfDescriptorExtractor extractor; 

    cv::Mat descriptors_1, descriptors_2; 

    extractor.compute(tempMat1, keypoints_1, descriptors_1); 
    extractor.compute(tempMat2, keypoints_2, descriptors_2); 

    std::vector<cv::Point2f> obj_corners(4); 

    //Get the corners from the object 
    obj_corners[0] = (cvPoint(0,0)); 
    obj_corners[1] = (cvPoint(tempMat2.cols,0)); 
    obj_corners[2] = (cvPoint(tempMat2.cols,tempMat2.rows)); 
    obj_corners[3] = (cvPoint(0, tempMat2.rows)); 

    //-- Step 3: Matching descriptor vectors with a brute force matcher 
    //cv::BruteForceMatcher < cv::L2<float> > matcher; 
    cv::FlannBasedMatcher matcher; 
    //std::vector<cv::DMatch> matches; 
    std::vector<cv::vector<cv::DMatch > > matches; 

    std::vector<cv::DMatch > good_matches; 
    std::vector<cv::Point2f> obj; 
    std::vector<cv::Point2f> scene; 
    std::vector<cv::Point2f> scene_corners(4); 
    cv::Mat H; 

    matcher.knnMatch(descriptors_2, descriptors_1, matches,2); 

    for(int i = 0; i < cv::min(tempMat1.rows-1,(int) matches.size()); i++) { 

     if((matches[i][0].distance < 0.6*(matches[i][1].distance)) && ((int) matches[i].size()<=2 && (int) matches[i].size()>0)) { 
      good_matches.push_back(matches[i][0]); 
     } 
    } 
    cv::Mat img_matches; 
    drawMatches(tempMat2, keypoints_2, tempMat1, keypoints_1, good_matches, img_matches); 

    NSLog(@"good matches %lu",good_matches.size()); 

    if (good_matches.size() >= 4) { 

     for(int i = 0; i < good_matches.size(); i++) { 
      //Get the keypoints from the good matches 
      obj.push_back(keypoints_2[ good_matches[i].queryIdx ].pt); 
      scene.push_back(keypoints_1[ good_matches[i].trainIdx ].pt); 
     } 

     H = findHomography(obj, scene, CV_RANSAC); 

     perspectiveTransform(obj_corners, scene_corners, H); 

     NSLog(@"%f %f",scene_corners[0].x,scene_corners[0].y); 
     NSLog(@"%f %f",scene_corners[1].x,scene_corners[1].y); 
     NSLog(@"%f %f",scene_corners[2].x,scene_corners[2].y); 
     NSLog(@"%f %f",scene_corners[3].x,scene_corners[3].y); 


     //Draw lines between the corners (the mapped object in the scene image) 
     line(tempMat1, scene_corners[0], scene_corners[1], cvScalar(0, 255, 0), 4); 

     line(tempMat1, scene_corners[1], scene_corners[2], cvScalar(0, 255, 0), 4); 

     line(tempMat1, scene_corners[2], scene_corners[3], cvScalar(0, 255, 0), 4); 

     line(tempMat1, scene_corners[3], scene_corners[0], cvScalar(0, 255, 0), 4); 
    } 

    // View matching.. 

    UIImage *resultimage = [UIImage imageWithCVMat:img_matches]; 
    UIImageView *imageview = [[UIImageView alloc] initWithImage:resultimage]; 
    imageview.frame = CGRectMake(0, 0, 320, 240); 
    [self.view addSubview:imageview]; 

    // View Result 

    UIImage *resultimage2 = [UIImage imageWithCVMat:tempMat1]; 
    UIImageView *imageview2 = [[UIImageView alloc] initWithImage:resultimage2]; 
    imageview2.frame = CGRectMake(0, 240, 320, 240); 
    [self.view addSubview:imageview2]; 
}