corrispondenza modello Imge (in scala) Principale/ingrandisci

Question

voglio trovare/immagine/template subimage check-immagine principale e vogliono sapere le sue coordinate,

Ho usato il codice dato al seguente link per la sua attuazione a,

Check presence of subimage in image in iOS

si sta lavorando bene, se la dimensione dell'immagine modello è esattamente uguale dimensione della parte corrispondente di immagine ingrandita.

Ma non fornisce correttamente i risultati se l'immagine secondaria viene ridimensionata o ingrandita rispetto alla parte corrispondente di un'immagine più grande.

Answer 1

Usa rilevamento funzione OpenCV. è più preciso di template matching ..

Si prega di provare con questo codice ..

-(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]; 
}