我正在创建一个应用程序,它将输入图像与数据库中的图像相匹配。
我仍然使用此代码:
String path = Environment.getExternalStorageDirectory().getAbsolutePath();
Bitmap objectbmp = BitmapFactory.decodeFile(path+"/Sample/Template.jpg");
Bitmap scenebmp = BitmapFactory.decodeFile(path+"/Sample/Input.jpg");
Mat object = new Mat(); //from the database
Mat scene = new Mat(); //user's input image
// convert bitmap to MAT
Utils.bitmapToMat(objectbmp, object);
Utils.bitmapToMat(scenebmp, scene);
//Feature Detection
FeatureDetector orbDetector = FeatureDetector.create(FeatureDetector.ORB);
DescriptorExtractor orbextractor = DescriptorExtractor.create(DescriptorExtractor.ORB);
MatOfKeyPoint keypoints_object = new MatOfKeyPoint();
MatOfKeyPoint keypoints_scene = new MatOfKeyPoint();
Mat descriptors_object = new Mat();
Mat descriptors_scene = new Mat();
//Getting the keypoints
orbDetector.detect( object, keypoints_object );
orbDetector.detect( scene, keypoints_scene );
//Compute descriptors
orbextractor.compute( object, keypoints_object, descriptors_object );
orbextractor.compute( scene, keypoints_scene, descriptors_scene );
//Match with Brute Force
MatOfDMatch matches = new MatOfDMatch();
DescriptorMatcher matcher;
matcher = DescriptorMatcher.create(DescriptorMatcher.BRUTEFORCE);
matcher.match( descriptors_object, descriptors_scene, matches );
double max_dist = 0;
double min_dist = 100;
List<DMatch> matchesList = matches.toList();
//-- Quick calculation of max and min distances between keypoints
for( int i = 0; i < descriptors_object.rows(); i++ )
{ double dist = matchesList.get(i).distance;
if( dist < min_dist ) min_dist = dist;
if( dist > max_dist ) max_dist = dist;
}
LinkedList<DMatch> good_matches = new LinkedList<DMatch>();
for( int i = 0; i < descriptors_object.rows(); i++ )
{ if( matchesList.get(i).distance <= 3*min_dist )
{ good_matches.addLast( matchesList.get(i));
}
}
我能够制作和计算好的比赛,我想要的是知道两个匹配的图像之间的匹配率,如:
输入 - Template1 = 35% 输入 - Template2 = 12% .....................
怎么做?
答案 0 :(得分:1)
您可以像goodMatches / totMatches一样计算匹配率,即匹配的准确性。
实际上有不同的方法可以做到这一点。常见的是:
我在Android应用程序中实现了Java中的前两个(我使用ORB作为功能)。
private List<MatOfDMatch> crossCheck(List<DMatch> matches12, List<DMatch> matches21, List<MatOfDMatch> knn_matches) {
List<MatOfDMatch> good_matches = new ArrayList<MatOfDMatch>();
for(int i=0; i<matches12.size(); i++)
{
DMatch forward = matches12.get(i);
DMatch backward = matches21.get(forward.trainIdx);
if(backward.trainIdx == forward.queryIdx)
good_matches.add(knn_matches.get(i)); //k=2
}
return good_matches;
}
private List<MatOfDMatch> ratioCheck(List<MatOfDMatch> knn_matches, float ratio) {
List<MatOfDMatch> good_matches = new ArrayList<MatOfDMatch>();
for(int i=0; i<knn_matches.size(); i++)
{
List<DMatch> subList = knn_matches.get(i).toList();
if(subList.size()>=2)
{
Float first_distance = subList.get(0).distance;
Float second_distance = subList.get(1).distance;
if((first_distance/second_distance) <= ratio)
good_matches.add(knn_matches.get(i));
}
}
return good_matches;
}