}
}
+struct KP_LessThan
+{
+ KP_LessThan(const vector<KeyPoint>& _kp) : kp(&_kp) {}
+ bool operator()(int i, int j) const
+ {
+ return (*kp)[i].class_id < (*kp)[j].class_id;
+ }
+ const vector<KeyPoint>* kp;
+};
+
void OpponentColorDescriptorExtractor::computeImpl( const Mat& bgrImage, vector<KeyPoint>& keypoints, Mat& descriptors ) const
{
vector<Mat> opponentChannels;
convertBGRImageToOpponentColorSpace( bgrImage, opponentChannels );
- // Compute descriptors three times, once for each Opponent channel
- // and concatenate into a single color surf descriptor
+ const int N = 3; // channels count
+ vector<KeyPoint> channelKeypoints[N];
+ Mat channelDescriptors[N];
+ vector<int> idxs[N];
+
+ // Compute descriptors three times, once for each Opponent channel to concatenate into a single color descriptor
+ for( int ci = 0; ci < N; ci++ )
+ {
+ channelKeypoints[ci].insert( channelKeypoints[ci].begin(), keypoints.begin(), keypoints.end() );
+ // Use class_id member to get indices into initial keypoints vector
+ for( size_t ki = 0; ki < channelKeypoints[ci].size(); ki++ )
+ channelKeypoints[ci][ki].class_id = ki;
+
+ descriptorExtractor->compute( opponentChannels[ci], channelKeypoints[ci], channelDescriptors[ci] );
+ idxs[ci].resize( channelKeypoints[ci].size() );
+ for( size_t ki = 0; ki < channelKeypoints[ci].size(); ki++ )
+ {
+ idxs[ci][ki] = ki;
+ }
+ std::sort( idxs[ci].begin(), idxs[ci].end(), KP_LessThan(channelKeypoints[ci]) );
+ }
+
+ vector<KeyPoint> outKeypoints;
+ outKeypoints.reserve( keypoints.size() );
+
int descriptorSize = descriptorExtractor->descriptorSize();
- descriptors.create( static_cast<int>(keypoints.size()), 3*descriptorSize, descriptorExtractor->descriptorType() );
- for( int i = 0; i < 3/*channel count*/; i++ )
+ Mat mergedDescriptors( (int)keypoints.size(), 3*descriptorSize, descriptorExtractor->descriptorType() );
+ int mergedCount = 0;
+ // cp - current channel position
+ for( size_t cp[] = {0, 0, 0}; cp[0] < channelKeypoints[0].size() && cp[1] < channelKeypoints[1].size() && cp[2] < channelKeypoints[2].size(); )
{
- CV_Assert( opponentChannels[i].type() == CV_8UC1 );
- Mat opponentDescriptors = descriptors.colRange( i*descriptorSize, (i+1)*descriptorSize );
- descriptorExtractor->compute( opponentChannels[i], keypoints, opponentDescriptors );
+ const int maxInitIdx = std::max( channelKeypoints[0][idxs[0][cp[0]]].class_id,
+ std::max( channelKeypoints[1][idxs[1][cp[1]]].class_id,
+ channelKeypoints[2][idxs[2][cp[2]]].class_id ) );
+
+ while( channelKeypoints[0][idxs[0][cp[0]]].class_id < maxInitIdx && cp[0] < channelKeypoints[0].size() ) { cp[0]++; }
+ while( channelKeypoints[1][idxs[1][cp[1]]].class_id < maxInitIdx && cp[1] < channelKeypoints[1].size() ) { cp[1]++; }
+ while( channelKeypoints[2][idxs[2][cp[2]]].class_id < maxInitIdx && cp[2] < channelKeypoints[2].size() ) { cp[2]++; }
+ if( cp[0] >= channelKeypoints[0].size() || cp[1] >= channelKeypoints[1].size() || cp[2] >= channelKeypoints[2].size() )
+ break;
+
+ if( channelKeypoints[0][idxs[0][cp[0]]].class_id == maxInitIdx &&
+ channelKeypoints[1][idxs[1][cp[1]]].class_id == maxInitIdx &&
+ channelKeypoints[2][idxs[2][cp[2]]].class_id == maxInitIdx )
+ {
+ outKeypoints.push_back( keypoints[maxInitIdx] );
+ // merge descriptors
+ for( int ci = 0; ci < N; ci++ )
+ {
+ Mat dst = mergedDescriptors(Range(mergedCount, mergedCount+1), Range(ci*descriptorSize, (ci+1)*descriptorSize));
+ channelDescriptors[ci].row( idxs[ci][cp[ci]] ).copyTo( dst );
+ cp[ci]++;
+ }
+ mergedCount++;
+ }
}
+ mergedDescriptors.rowRange(0, mergedCount).copyTo( descriptors );
+ std::swap( outKeypoints, keypoints );
}
void OpponentColorDescriptorExtractor::read( const FileNode& fn )