Added sample for GenericDescriptorMatch

modules/features2d/include/opencv2/features2d/features2d.hpp

@@ -1751,6 +1751,8 @@ public:
     // Writes match object to a file storage
     virtual void write( FileStorage& fs ) const {};
     
+    static GenericDescriptorMatch* CreateDescriptorMatch( const string &alg_name, const string &params_filename = string () );
+
 protected:
     KeyPointCollection collection;
 };

modules/features2d/src/descriptors.cpp

@@ -226,6 +226,38 @@ void GenericDescriptorMatch::clear()
 {
     collection.clear();
 }
+
+GenericDescriptorMatch* GenericDescriptorMatch::CreateDescriptorMatch( const string &alg_name, const string &params_filename )
+{
+    GenericDescriptorMatch *descriptorMatch = 0;
+    if( ! alg_name.compare ("one_way") )
+    {
+        descriptorMatch = new OneWayDescriptorMatch ();
+    }
+    else if( ! alg_name.compare ("fern") )
+    {
+        FernDescriptorMatch::Params params;
+        params.signatureSize = INT_MAX;
+        descriptorMatch = new FernDescriptorMatch (params);
+    }
+    else if( ! alg_name.compare ("calonder") )
+    {
+        descriptorMatch = new CalonderDescriptorMatch ();
+    }
+
+    if( !params_filename.empty() && descriptorMatch != 0 )
+    {
+        FileStorage fs = FileStorage( params_filename, FileStorage::READ );
+        if( fs.isOpened() )
+        {
+            descriptorMatch->read( fs.root() );
+            fs.release();
+        }
+    }
+
+    return descriptorMatch;
+}
+
 /****************************************************************************************\
 *                                OneWayDescriptorMatch                                  *
 \****************************************************************************************/

samples/c/calonder_params.xml

+<?xml version="1.0"?>
+<opencv_storage>
+    <numTrees>20</numTrees>
+    <depth>7</depth>
+    <views>1000</views>
+    <patchSize>20</patchSize>
+    <reducedNumDim>30</reducedNumDim>
+    <numQuantBits>4</numQuantBits>
+    <printStatus>1</printStatus>
+</opencv_storage>

samples/c/fern_params.xml

+<?xml version="1.0"?>
+<opencv_storage>
+    <nclasses>0</nclasses>
+    <patchSize>31</patchSize>
+    <signatureSize>INT_MAX</signatureSize>
+    <nstructs>50</nstructs>
+    <structSize>9</structSize>
+    <nviews>1000</nviews>
+    <compressionMethod>0</compressionMethod>
+</opencv_storage>

samples/c/match_sample.cpp

+#include <cv.h>
+#include <cvaux.h>
+#include <highgui.h>
+
+#include <string>
+
+using namespace cv;
+
+IplImage* DrawCorrespondences(IplImage* img1, const vector<KeyPoint>& features1, IplImage* img2,
+                              const vector<KeyPoint>& features2, const vector<int>& desc_idx);
+
+int main(int argc, char** argv)
+{
+    if (argc != 5)
+    {
+        printf("Format: \n./match_sample [image1] [image2] [algorithm] [XML params]\n");
+        printf("For example: ./match_sample scene_l.bmp scene_r.bmp fern fern_params.xml\n");
+        return 0;
+    }
+
+    std::string img1_name = std::string(argv[1]);
+    std::string img2_name = std::string(argv[2]);
+    std::string alg_name = std::string(argv[3]);
+    std::string params_filename = std::string(argv[4]);
+
+    GenericDescriptorMatch *descriptorMatch = GenericDescriptorMatch::CreateDescriptorMatch (alg_name, params_filename);
+    if( descriptorMatch == 0 )
+    {
+        printf ("Cannot create descriptor\n");
+        return 0;
+    }
+
+    //printf("Reading the images...\n");
+    IplImage* img1 = cvLoadImage(img1_name.c_str(), CV_LOAD_IMAGE_GRAYSCALE);
+    IplImage* img2 = cvLoadImage(img2_name.c_str(), CV_LOAD_IMAGE_GRAYSCALE);
+    
+    // extract keypoints from the first image
+    SURF surf_extractor(5.0e3);
+    vector<KeyPoint> keypoints1;
+
+    // printf("Extracting keypoints\n");
+    surf_extractor(img1, Mat(), keypoints1);
+    
+    printf("Extracted %d keypoints from the first image\n", (int)keypoints1.size());
+
+    vector<KeyPoint> keypoints2;
+    surf_extractor(img2, Mat(), keypoints2);
+    printf("Extracted %d keypoints from the second image\n", (int)keypoints2.size());
+
+    printf("Finding nearest neighbors... \n");
+    // find NN for each of keypoints2 in keypoints1
+    descriptorMatch->add( img1, keypoints1 );
+    vector<int> matches2to1;
+    matches2to1.resize(keypoints2.size());
+    descriptorMatch->match( img2, keypoints2, matches2to1 );
+    printf("Done\n");
+
+    IplImage* img_corr = DrawCorrespondences(img1, keypoints1, img2, keypoints2, matches2to1);
+
+    cvNamedWindow("correspondences", 1);
+    cvShowImage("correspondences", img_corr);
+    cvWaitKey(0);
+
+    cvReleaseImage(&img1);
+    cvReleaseImage(&img2);
+    cvReleaseImage(&img_corr);
+    delete descriptorMatch;
+}
+
+IplImage* DrawCorrespondences(IplImage* img1, const vector<KeyPoint>& features1, IplImage* img2,
+                              const vector<KeyPoint>& features2, const vector<int>& desc_idx)
+{
+    IplImage* img_corr = cvCreateImage(cvSize(img1->width + img2->width, MAX(img1->height, img2->height)),
+                                       IPL_DEPTH_8U, 3);
+    cvSetImageROI(img_corr, cvRect(0, 0, img1->width, img1->height));
+    cvCvtColor(img1, img_corr, CV_GRAY2RGB);
+    cvSetImageROI(img_corr, cvRect(img1->width, 0, img2->width, img2->height));
+    cvCvtColor(img2, img_corr, CV_GRAY2RGB);
+    cvResetImageROI(img_corr);
+
+    for (size_t i = 0; i < features1.size(); i++)
+    {
+        cvCircle(img_corr, features1[i].pt, 3, CV_RGB(255, 0, 0));
+    }
+
+    for (size_t i = 0; i < features2.size(); i++)
+    {
+        CvPoint pt = cvPoint(features2[i].pt.x + img1->width, features2[i].pt.y);
+        cvCircle(img_corr, pt, 3, CV_RGB(255, 0, 0));
+        cvLine(img_corr, features1[desc_idx[i]].pt, pt, CV_RGB(0, 255, 0));
+    }
+
+    return img_corr;
+}