added sample for c++ version of latent svm

samples/cpp/latentsvm_multidetect.cpp

+#include <iostream>
+#include "opencv2/objdetect/objdetect.hpp"
+#include "opencv2/highgui/highgui.hpp"
+#include "opencv2/contrib/contrib.hpp"
+
+#ifdef WIN32
+//#include <io.h>
+#else
+#include <dirent.h>
+#endif
+
+#ifdef HAVE_CVCONFIG_H 
+#include <cvconfig.h> 
+#endif
+
+#ifdef HAVE_TBB
+#include "tbb/task_scheduler_init.h"
+#endif
+
+using namespace std;
+using namespace cv;
+
+void help()
+{
+    cout << "This program demonstrated the use of the latentSVM detector." << endl <<
+            "It reads in a trained object models and then uses them to detect the object in an images" << endl <<
+             endl <<
+            "Call:" << endl <<
+            "./latentsvm_multidetect <images_folder> <models_folder> [<threads_number>]" << endl <<
+            "Example of models_folder is opencv_extra/testdata/cv/latentsvmdetector/models_VOC2007" << endl <<
+             endl <<
+            "Keys:" << endl <<
+            "'n' - to go to the next image;" << endl <<
+            "'esc' - to quit." << endl <<
+            endl;
+}
+
+void detectAndDrawObjects( Mat& image, LatentSvmDetector& detector, const vector<Scalar>& colors, int numThreads )
+{
+    vector<LatentSvmDetector::ObjectDetection> detections;
+
+    TickMeter tm;
+    tm.start();
+    detector.detect( image, detections, 0.5f, numThreads);
+    tm.stop();
+
+    cout << "Detection time = " << tm.getTimeSec() << " sec" << endl;
+
+    const vector<string> classNames = detector.getClassNames();
+    CV_Assert( colors.size() == classNames.size() );
+
+    for( size_t i = 0; i < detections.size(); i++ )
+    {
+        const LatentSvmDetector::ObjectDetection& od = detections[i];
+        rectangle( image, od.rect, colors[od.classID], 2 );
+        putText( image, classNames[od.classID], Point(od.rect.x+2,od.rect.y+9), FONT_HERSHEY_SIMPLEX, 0.35, colors[od.classID], 1 );
+    }
+}
+
+void readDirectory( const string& directoryName, vector<string>& filenames, bool addDirectoryName=true )
+{
+    filenames.clear();
+
+#ifdef WIN32
+//    struct _finddata_t s_file;
+//    string str = directoryName + "\\*.*";
+
+//    intptr_t h_file = _findfirst( str.c_str(), &s_file );
+//    if( h_file == -1L )
+//    {
+//        do
+//        {
+//            if( addDirectoryName )
+//                filenames.push_back(directoryName + "/" + s_file.name);
+//            else
+//                filenames.push_back((string)s_file.name);
+//        }
+//        while( _findnext( h_file, &s_file ) == 0 );
+//    }
+//    _findclose( h_file );
+#else
+    DIR* dir = opendir( directoryName.c_str() );
+    if( dir != NULL )
+    {
+        struct dirent* dent;
+        while( (dent = readdir(dir)) != NULL )
+        {
+            if( addDirectoryName )
+                filenames.push_back( directoryName + "/" + string(dent->d_name) );
+            else
+                filenames.push_back( string(dent->d_name) );
+        }
+    }
+#endif
+
+    sort( filenames.begin(), filenames.end() );
+}
+
+void fillRngColors( vector<Scalar>& colors )
+{
+    Mat m = Mat(colors).reshape(1,1);
+    randu( m, 0, 255 );
+}
+
+int main(int argc, char* argv[])
+{
+	help();
+
+    string images_folder, models_folder;
+    int numThreads = -1;
+    if( argc > 2 )
+	{
+        images_folder = argv[1];
+        models_folder = argv[2];
+        if( argc > 3 ) numThreads = atoi(argv[3]);
+	}
+
+    vector<string> images_filenames, models_filenames;
+    readDirectory( images_folder, images_filenames );
+    readDirectory( models_folder, models_filenames );
+
+    LatentSvmDetector detector( models_filenames );
+    if( detector.empty() )
+    {
+        cout << "Models cann't be loaded" << endl;
+        exit(-1);
+    }
+
+    vector<Scalar> colors( detector.getClassNames().size() );
+    fillRngColors( colors );
+
+    for( size_t i = 0; i < images_filenames.size(); i++ )
+    {
+        Mat image = imread( images_filenames[i] );
+        if( image.empty() )  continue;
+
+        cout << "Process image " << images_filenames[i] << endl;
+        detectAndDrawObjects( image, detector, colors, numThreads );
+
+        imshow( "result", image );
+
+        while(1)
+        {
+            int c = waitKey();
+            if( (char)c == 'n')
+                break;
+            else if( (char)c == '\x1b' )
+                exit(0);
+        }
+    }
+    
+	return 0;
+}