[WIP] merge tracks

alicevision · Oct 4, 2023 · 8b8dcc0 · 8b8dcc0
1 parent a68c925
commit 8b8dcc0
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Showing 2 changed files with 49 additions and 11 deletions.
diff --git a/src/aliceVision/track/TracksBuilder.cpp b/src/aliceVision/track/TracksBuilder.cpp
@@ -40,8 +40,6 @@ namespace track {
 using namespace aliceVision::matching;
 using namespace lemon;
 
-// IndexedFeaturePair is: pair<viewId, keypointId>
-using IndexedFeaturePair = std::pair<std::size_t, KeypointId>;
 using IndexMap = lemon::ListDigraph::NodeMap<std::size_t>;
 using UnionFindObject = lemon::UnionFindEnum< IndexMap >;
 
@@ -76,7 +74,8 @@ TracksBuilder::TracksBuilder()
 TracksBuilder::~TracksBuilder() = default;
 
 void mergeTracks(const feature::MapFeaturesPerView& featuresPerView, const MapIndexToNode& map_indexToNode,
-                 const PairwiseMatches& pairwiseMatches, std::unique_ptr<TracksBuilderData>& _d)
+                 const PairwiseMatches& pairwiseMatches, std::unique_ptr<TracksBuilderData>& _d,
+                 stl::flat_map<IndexedFeaturePair, size_t>& _duplicateFeaturesMap)
 {
     // make the union according to duplicate features
     // (same position, scale and describer type, but different orientations)
@@ -86,7 +85,7 @@ void mergeTracks(const feature::MapFeaturesPerView& featuresPerView, const MapIn
     //        map of DuplicateFeatureId(x, y, scale) to
     //            pair of (set<featureId>, node)
     HashMap<size_t, HashMap<feature::EImageDescriberType,
-                            HashMap<DuplicateFeatureId, std::pair<std::set<size_t>, const MapIndexToNode::mapped_type*>>>>
+                    HashMap<DuplicateFeatureId, std::pair<std::set<size_t>, const MapIndexToNode::mapped_type*>>>>
         duplicateFeaturesPerView;
 
     // per viewId pair
@@ -150,6 +149,20 @@ void mergeTracks(const feature::MapFeaturesPerView& featuresPerView, const MapIn
             }
         }
     }
+
+    // fill duplicate features map
+    for(const auto& [viewId, duplicateFeaturesPerDesc] : duplicateFeaturesPerView)
+        for(const auto& [descType, duplicateFeatures] : duplicateFeaturesPerDesc)
+            for(const auto& [duplicateFeatureId, duplicateFeature] : duplicateFeatures)
+            {
+                auto& duplicateFeatureIdsSet = duplicateFeature.first;
+                size_t indexedFeaturePair_0 = *duplicateFeatureIdsSet.begin();
+                for(const auto& featureId : duplicateFeatureIdsSet)
+                {
+                    const auto& indexedFeaturePair_i = IndexedFeaturePair(viewId, KeypointId(descType, featureId));
+                    _duplicateFeaturesMap[indexedFeaturePair_i] = indexedFeaturePair_0;
+                }
+            }
 }
 
 void TracksBuilder::build(const PairwiseMatches& pairwiseMatches, const feature::MapFeaturesPerView* featuresPerView)
@@ -225,7 +238,7 @@ void TracksBuilder::build(const PairwiseMatches& pairwiseMatches, const feature:
   }
 
   if(featuresPerView != NULL)
-    mergeTracks(*featuresPerView, map_indexToNode, pairwiseMatches, _d);
+    mergeTracks(*featuresPerView, map_indexToNode, pairwiseMatches, _d, _duplicateFeaturesMap);
 }
 
 void TracksBuilder::filter(bool clearForks, std::size_t minTrackLength, bool multithreaded)
@@ -244,14 +257,31 @@ void TracksBuilder::filter(bool clearForks, std::size_t minTrackLength, bool mul
 
 #pragma omp single nowait
     {
-      std::size_t cpt = 0;
-      std::set<std::size_t> myset;
+      bool flag = false;
+      stl::flat_map<size_t, IndexedFeaturePair> myset;
       for(lemon::UnionFindEnum<IndexMap>::ItemIt iit(*_d->tracksUF, cit); iit != INVALID; ++iit)
       {
-        myset.insert(_d->map_nodeToIndex[iit].first);
-        ++cpt;
+        IndexedFeaturePair currentPair = _d->map_nodeToIndex[iit];
+        {
+          const auto& duplicateIt = _duplicateFeaturesMap.find(currentPair);
+          if(duplicateIt != _duplicateFeaturesMap.end())
+            currentPair.second.featIndex = duplicateIt->second;
+        }
+        const auto& myIt = myset.find(currentPair.first);
+        if(myIt != myset.end())
+        {
+          if(myIt->second < currentPair || currentPair < myIt->second)
+          {
+            flag = true;
+            // break if no minTrackLength ?
+          }
+        }
+        else
+        {
+          myset[currentPair.first] = currentPair;
+        }
       }
-      if((clearForks && myset.size() != cpt) || myset.size() < minTrackLength)
+      if((clearForks && flag) || myset.size() < minTrackLength)
       {
 #pragma omp critical
         set_classToErase.insert(cit.operator int());
@@ -302,7 +332,11 @@ void TracksBuilder::exportToSTL(TracksMap& allTracks) const
       // all descType inside the track will be the same
       outTrack.descType = currentPair.second.descType;
       // overwrites featureIndex if clearForks is False (value is False by default in Meshroom and True by default in AliceVision)
-      outTrack.featPerView[currentPair.first] = currentPair.second.featIndex;
+      const auto& duplicateIt = _duplicateFeaturesMap.find(currentPair);
+      if(duplicateIt != _duplicateFeaturesMap.end())
+        outTrack.featPerView[currentPair.first] = duplicateIt->second;
+      else
+        outTrack.featPerView[currentPair.first] = currentPair.second.featIndex;
     }
   }
 }

diff --git a/src/aliceVision/track/TracksBuilder.hpp b/src/aliceVision/track/TracksBuilder.hpp
@@ -15,6 +15,9 @@
 namespace aliceVision {
 namespace track {
 
+// IndexedFeaturePair is: pair<viewId, keypointId>
+using IndexedFeaturePair = std::pair<std::size_t, KeypointId>;
+
 struct TracksBuilderData;
 
 /**
@@ -84,6 +87,7 @@ class TracksBuilder
 
 private:
     std::unique_ptr<TracksBuilderData> _d;
+    stl::flat_map<IndexedFeaturePair, size_t> _duplicateFeaturesMap;
 };
 
 } // namespace track