remove all duplicate pixels from clustering

cms-sw · Apr 13, 2022 · d50b2f5 · d50b2f5
1 parent 320b545
commit d50b2f5
Show file tree

Hide file tree

Showing 3 changed files with 31 additions and 6 deletions.
diff --git a/DataFormats/SiPixelCluster/interface/SiPixelCluster.h b/DataFormats/SiPixelCluster/interface/SiPixelCluster.h
@@ -60,6 +60,7 @@ class SiPixelCluster {
     constexpr int row() const { return row_; }
     constexpr int col() const { return col_; }
     constexpr PixelPos operator+(const Shift& shift) const { return PixelPos(row() + shift.dx(), col() + shift.dy()); }
+    constexpr bool operator==(const PixelPos& pos) const { return (row() == pos.row() && col() == pos.col()); }
 
   private:
     int row_;

diff --git a/RecoLocalTracker/SiPixelClusterizer/plugins/PixelThresholdClusterizer.cc b/RecoLocalTracker/SiPixelClusterizer/plugins/PixelThresholdClusterizer.cc
@@ -63,6 +63,7 @@ PixelThresholdClusterizer::PixelThresholdClusterizer(edm::ParameterSet const& co
       doSplitClusters(conf.getParameter<bool>("SplitClusters")) {
   theBuffer.setSize(theNumOfRows, theNumOfCols);
   theFakePixels.clear();
+  thePixelOccurrence.clear();
 }
 /////////////////////////////////////////////////////////////////////////////
 PixelThresholdClusterizer::~PixelThresholdClusterizer() {}
@@ -112,6 +113,8 @@ bool PixelThresholdClusterizer::setup(const PixelGeomDetUnit* pixDet) {
 
   theFakePixels.resize(nrows * ncols, false);
 
+  thePixelOccurrence.resize(nrows * ncols, 0);
+
   return true;
 }
 //----------------------------------------------------------------------------
@@ -185,6 +188,8 @@ void PixelThresholdClusterizer::clusterizeDetUnitT(const T& input,
   clear_buffer(begin, end);
 
   theFakePixels.clear();
+
+  thePixelOccurrence.clear();
 }
 
 //----------------------------------------------------------------------------
@@ -291,12 +296,29 @@ void PixelThresholdClusterizer::copy_to_buffer(DigiIterator begin, DigiIterator
     */
 
     if (adc >= thePixelThreshold) {
-      theBuffer.set_adc(row, col, adc);
-      // VV: add pixel to the fake list. Only when running on digi collection
-      if (di->flag() != 0)
-        theFakePixels[row * theNumOfCols + col] = true;
-      if (adc >= theSeedThreshold)
-        theSeeds.push_back(SiPixelCluster::PixelPos(row, col));
+      thePixelOccurrence[theBuffer.index(row, col)]++; // increment the occurrence counter
+      uint8_t occurrence = thePixelOccurrence[theBuffer.index(row, col)]; // get the occurrence counter
+
+      switch(occurrence) {
+        // the 1st occurrence (standard treatment)
+        case 1:
+          theBuffer.set_adc(row, col, adc);
+          // VV: add pixel to the fake list. Only when running on digi collection
+          if (di->flag() != 0)
+            theFakePixels[row * theNumOfCols + col] = true;
+          if (adc >= theSeedThreshold)
+            theSeeds.push_back(SiPixelCluster::PixelPos(row, col));
+          break;
+
+        // the 2nd occurrence (duplicate pixel: reset the buffer to 0 and remove from the list of seed pixels)
+        case 2:
+          theBuffer.set_adc(row, col, 0);
+          std::remove(theSeeds.begin(), theSeeds.end(), SiPixelCluster::PixelPos(row, col));
+          break;
+
+        // in case a pixel appears more than twice, nothing needs to be done because it was already removed at the 2nd occurrence
+
+      }
     }
   }
   assert(i == (end - begin));

diff --git a/RecoLocalTracker/SiPixelClusterizer/plugins/PixelThresholdClusterizer.h b/RecoLocalTracker/SiPixelClusterizer/plugins/PixelThresholdClusterizer.h
@@ -92,6 +92,8 @@ class dso_hidden PixelThresholdClusterizer : public PixelClusterizerBase {
 
   std::vector<bool> theFakePixels;  // fake pixels introduced to guide clustering
 
+  std::vector<uint8_t> thePixelOccurrence;  // the number of times each pixel occurs (for tracking duplicate pixels)
+
   //! Clustering-related quantities:
   float thePixelThresholdInNoiseUnits;    // Pixel threshold in units of noise
   float theSeedThresholdInNoiseUnits;     // Pixel cluster seed in units of noise