Update PR after mdim review.

modules/features2d/doc/object_categorization.rst

@@ -118,6 +118,7 @@ The class declaration is the following: ::
         public:
             BOWImgDescriptorExtractor( const Ptr<DescriptorExtractor>& dextractor,
                                        const Ptr<DescriptorMatcher>& dmatcher );
+            BOWImgDescriptorExtractor( const Ptr<DescriptorMatcher>& dmatcher );
             virtual ~BOWImgDescriptorExtractor(){}
 
             void setVocabulary( const Mat& vocabulary );
@@ -126,6 +127,8 @@ The class declaration is the following: ::
                           Mat& imgDescriptor,
                           vector<vector<int> >* pointIdxsOfClusters=0,
                           Mat* descriptors=0 );
+            void compute( const Mat& descriptors, Mat& imgDescriptor,
+                          std::vector<std::vector<int> >* pointIdxsOfClusters=0 );
             int descriptorSize() const;
             int descriptorType() const;
 
@@ -141,6 +144,7 @@ BOWImgDescriptorExtractor::BOWImgDescriptorExtractor
 The constructor.
 
 .. ocv:function:: BOWImgDescriptorExtractor::BOWImgDescriptorExtractor(           const Ptr<DescriptorExtractor>& dextractor,          const Ptr<DescriptorMatcher>& dmatcher )
+.. ocv:function:: BOWImgDescriptorExtractor::BOWImgDescriptorExtractor(           const Ptr<DescriptorMatcher>& dmatcher )
 
     :param dextractor: Descriptor extractor that is used to compute descriptors for an input image and its keypoints.
 
@@ -171,11 +175,14 @@ BOWImgDescriptorExtractor::compute
 Computes an image descriptor using the set visual vocabulary.
 
 .. ocv:function:: void BOWImgDescriptorExtractor::compute( const Mat& image, vector<KeyPoint>& keypoints, Mat& imgDescriptor, vector<vector<int> >* pointIdxsOfClusters=0, Mat* descriptors=0 )
+.. ocv:function:: void BOWImgDescriptorExtractor::compute( const Mat& descriptors, Mat& imgDescriptor, std::vector<std::vector<int> >* pointIdxsOfClusters )
 
     :param image: Image, for which the descriptor is computed.
 
     :param keypoints: Keypoints detected in the input image.
 
+    :param descriptors: Computed descriptors to match with vocabulary.
+
     :param imgDescriptor: Computed output image descriptor.
 
     :param pointIdxsOfClusters: Indices of keypoints that belong to the cluster. This means that ``pointIdxsOfClusters[i]``  are keypoint indices that belong to the  ``i`` -th cluster (word of vocabulary) returned if it is non-zero.

modules/features2d/include/opencv2/features2d.hpp

@@ -1502,12 +1502,15 @@ class CV_EXPORTS BOWImgDescriptorExtractor
 public:
     BOWImgDescriptorExtractor( const Ptr<DescriptorExtractor>& dextractor,
                                const Ptr<DescriptorMatcher>& dmatcher );
+    BOWImgDescriptorExtractor( const Ptr<DescriptorMatcher>& dmatcher );
     virtual ~BOWImgDescriptorExtractor();
 
     void setVocabulary( const Mat& vocabulary );
     const Mat& getVocabulary() const;
     void compute( const Mat& image, std::vector<KeyPoint>& keypoints, Mat& imgDescriptor,
                   std::vector<std::vector<int> >* pointIdxsOfClusters=0, Mat* descriptors=0 );
+    void compute( const Mat& keypointDescriptors, Mat& imgDescriptor,
+                  std::vector<std::vector<int> >* pointIdxsOfClusters=0 );
     // compute() is not constant because DescriptorMatcher::match is not constant
 
     int descriptorSize() const;
@@ -1519,41 +1522,6 @@ protected:
     Ptr<DescriptorMatcher> dmatcher;
 };
 
-/*
- * Class to match image descriptors using bag of visual words.
- */
-class CV_EXPORTS BOWImgDescriptorMatcher
-{
-public:
-    BOWImgDescriptorMatcher( const Ptr<DescriptorMatcher>& _dmatcher );
-    virtual ~BOWImgDescriptorMatcher();
-
-    /*
-     * Compute the matching of the current descriptor according to the vocabulary.
-     *
-     * vocDescriptor         the descriptors to match
-     * pointIdxsOfClusters   vector of matching
-     */
-    void compute( const Mat & descriptors, Mat& vocDescriptor, std::vector< std::vector< int > > * pointIdxsOfClusters = 0 );
-
-    /*
-     * Set the vocabulary
-     */
-    void setVocabulary( const Mat& vocabulary );
-    const Mat& getVocabulary() const;
-    
-    int descriptorSize() const;
-    int descriptorType() const;
-
-protected:
-    Mat vocabulary;
-    Ptr<DescriptorMatcher> dmatcher;
-
-private:
-    int _type;
-};
-
-
 } /* namespace cv */
 
 #endif

modules/features2d/src/bagofwords.cpp

@@ -121,6 +121,10 @@ BOWImgDescriptorExtractor::BOWImgDescriptorExtractor( const Ptr<DescriptorExtrac
     dextractor(_dextractor), dmatcher(_dmatcher)
 {}
 
+BOWImgDescriptorExtractor::BOWImgDescriptorExtractor( const Ptr<DescriptorMatcher>& _dmatcher ) :
+    dmatcher(_dmatcher)
+{}
+
 BOWImgDescriptorExtractor::~BOWImgDescriptorExtractor()
 {}
 
@@ -144,38 +148,11 @@ void BOWImgDescriptorExtractor::compute( const Mat& image, std::vector<KeyPoint>
     if( keypoints.empty() )
         return;
 
-    int clusterCount = descriptorSize(); // = vocabulary.rows
-
     // Compute descriptors for the image.
     Mat descriptors;
     dextractor->compute( image, keypoints, descriptors );
 
-    // Match keypoint descriptors to cluster center (to vocabulary)
-    std::vector<DMatch> matches;
-    dmatcher->match( descriptors, matches );
-
-    // Compute image descriptor
-    if( pointIdxsOfClusters )
-    {
-        pointIdxsOfClusters->clear();
-        pointIdxsOfClusters->resize(clusterCount);
-    }
-
-    imgDescriptor = Mat( 1, clusterCount, descriptorType(), Scalar::all(0.0) );
-    float *dptr = (float*)imgDescriptor.data;
-    for( size_t i = 0; i < matches.size(); i++ )
-    {
-        int queryIdx = matches[i].queryIdx;
-        int trainIdx = matches[i].trainIdx; // cluster index
-        CV_Assert( queryIdx == (int)i );
-
-        dptr[trainIdx] = dptr[trainIdx] + 1.f;
-        if( pointIdxsOfClusters )
-            (*pointIdxsOfClusters)[trainIdx].push_back( queryIdx );
-    }
-
-    // Normalize image descriptor.
-    imgDescriptor /= descriptors.rows;
+    compute( descriptors, imgDescriptor, pointIdxsOfClusters );
 	
     // Add the descriptors of image keypoints
     if (_descriptors) {
@@ -193,44 +170,16 @@ int BOWImgDescriptorExtractor::descriptorType() const
     return CV_32FC1;
 }
 
-BOWImgDescriptorMatcher::BOWImgDescriptorMatcher( const Ptr<DescriptorMatcher>& _dmatcher ) :
-    dmatcher(_dmatcher),
-    _type( -1 )
-{}
-
-BOWImgDescriptorMatcher::~BOWImgDescriptorMatcher()
-{}
-
-void BOWImgDescriptorMatcher::setVocabulary( const Mat& _vocabulary )
-{
-    dmatcher->clear();
-    CV_Assert( _vocabulary.type() == CV_32F );
-    vocabulary = _vocabulary;
-    dmatcher->add( std::vector<Mat>(1, vocabulary) );
-}
-
-const Mat& BOWImgDescriptorMatcher::getVocabulary() const
+void BOWImgDescriptorExtractor::compute( const Mat& descriptors, Mat& imgDescriptor, std::vector<std::vector<int> >* pointIdxsOfClusters )
 {
-    return vocabulary;
-}
+    CV_Assert( vocabulary.empty() != false );
 
-void BOWImgDescriptorMatcher::compute( const Mat & descriptors, Mat& vocDescriptor, std::vector<std::vector<int> > * pointIdxsOfClusters )
-{
-    vocDescriptor.release();
-    
     int clusterCount = descriptorSize(); // = vocabulary.rows
 
-    _type = descriptors.type();
-
-    Mat _descriptors;
-    if( _type != CV_32F )
-        descriptors.convertTo( _descriptors, CV_32F );
-    else
-        descriptors.copyTo( _descriptors );
     // Match keypoint descriptors to cluster center (to vocabulary)
     std::vector<DMatch> matches;
-    dmatcher->match( _descriptors, matches );
-    
+    dmatcher->match( descriptors, matches );
+
     // Compute image descriptor
     if( pointIdxsOfClusters )
     {
@@ -238,8 +187,8 @@ void BOWImgDescriptorMatcher::compute( const Mat & descriptors, Mat& vocDescript
         pointIdxsOfClusters->resize(clusterCount);
     }
 
-    vocDescriptor = Mat::zeros( 1, clusterCount, descriptorType() );
-    float *dptr = (float*)vocDescriptor.data;
+    imgDescriptor = Mat( 1, clusterCount, descriptorType(), Scalar::all(0.0) );
+    float *dptr = (float*)imgDescriptor.data;
     for( size_t i = 0; i < matches.size(); i++ )
     {
         int queryIdx = matches[i].queryIdx;
@@ -252,17 +201,7 @@ void BOWImgDescriptorMatcher::compute( const Mat & descriptors, Mat& vocDescript
     }
 
     // Normalize image descriptor.
-    vocDescriptor /= descriptors.rows;
-}
-
-int BOWImgDescriptorMatcher::descriptorSize() const
-{
-    return vocabulary.empty() ? 0 : vocabulary.rows;
-}
-
-int BOWImgDescriptorMatcher::descriptorType() const
-{
-    return _type;
+    imgDescriptor /= descriptors.rows;
 }
 
 }