Adding hierarchical plate regions. The goal is to minimize unnecessary processing of regions within regions

src/misc_utilities/benchmark.cpp

@@ -150,7 +150,7 @@ int main( int argc, const char** argv )
         string fullpath = inDir + "/" + files[i];
         frame = imread( fullpath.c_str() );
 
-        vector<Rect> regions = plateDetector.detect(frame);
+        vector<PlateRegion> regions = plateDetector.detect(frame);
 
         imshow("Current LP", frame);
         waitKey(5);
@@ -200,7 +200,7 @@ int main( int argc, const char** argv )
         endToEndTimes.push_back(endToEndTime);
 
         getTime(&startTime);
-        vector<Rect> regions = plateDetector.detect(frame);
+        vector<PlateRegion> regions = plateDetector.detect(frame);
         getTime(&endTime);
 
         double regionDetectionTime = diffclock(startTime, endTime);
@@ -211,14 +211,14 @@ int main( int argc, const char** argv )
         {
           getTime(&startTime);
           char temp[5];
-          stateIdentifier.recognize(frame, regions[z], temp);
+          stateIdentifier.recognize(frame, regions[z].rect, temp);
           getTime(&endTime);
           double stateidTime = diffclock(startTime, endTime);
           cout << "\tRegion " << z << ": State ID time: " << stateidTime << "ms." << endl;
           stateIdTimes.push_back(stateidTime);
 
           getTime(&startTime);
-          LicensePlateCandidate lp(frame, regions[z], &config);
+          LicensePlateCandidate lp(frame, regions[z].rect, &config);
           lp.recognize();
           getTime(&endTime);
           double analysisTime = diffclock(startTime, endTime);

src/openalpr/alpr_impl.cpp

@@ -79,7 +79,7 @@ std::vector<AlprResult> AlprImpl::recognize(cv::Mat img)
 
 
   // Find all the candidate regions
-  vector<Rect> plateRegions = plateDetector->detect(img);
+  vector<PlateRegion> plateRegions = plateDetector->detect(img);
 
   // Get the number of threads specified and make sure the value is sane (cannot be greater than CPU cores or less than 1)
   int numThreads = config->multithreading_cores;
@@ -120,7 +120,7 @@ std::vector<AlprResult> AlprImpl::recognize(cv::Mat img)
   {
     for (int i = 0; i < plateRegions.size(); i++)
     {
-      rectangle(img, plateRegions[i], Scalar(0, 0, 255), 2);
+      rectangle(img, plateRegions[i].rect, Scalar(0, 0, 255), 2);
     }
     
     for (int i = 0; i < dispatcher.getRecognitionResults().size(); i++)
@@ -137,8 +137,9 @@ std::vector<AlprResult> AlprImpl::recognize(cv::Mat img)
     
     displayImage(config, "Main Image", img);
     // Pause indefinitely until they press a key
-    while ((char) cv::waitKey(50) == -1)
-      {}
+    cv::waitKey(1);
+    //while ((char) cv::waitKey(50) == -1)
+    //  {}
   }
 
   
@@ -163,7 +164,7 @@ void plateAnalysisThread(void* arg)
       cout << "Thread: " << tthread::this_thread::get_id() << " loop " << ++loop_count << endl;
     
     // Get a single plate region from the queue
-    Rect plateRegion = dispatcher->nextPlate();
+    PlateRegion plateRegion = dispatcher->nextPlate();
     
     Mat img = dispatcher->getImageCopy();
 
@@ -172,7 +173,7 @@ void plateAnalysisThread(void* arg)
       timespec platestarttime;
       getTime(&platestarttime);
       
-      LicensePlateCandidate lp(img, plateRegion, dispatcher->config);
+      LicensePlateCandidate lp(img, plateRegion.rect, dispatcher->config);
       
       lp.recognize();
 
@@ -192,7 +193,7 @@ void plateAnalysisThread(void* arg)
 	if (dispatcher->detectRegion)
 	{
 	  char statecode[4];
-	  plateResult.regionConfidence = dispatcher->stateIdentifier->recognize(img, plateRegion, statecode);
+	  plateResult.regionConfidence = dispatcher->stateIdentifier->recognize(img, plateRegion.rect, statecode);
 	  if (plateResult.regionConfidence > 0)
 	  {
 	    plateResult.region = statecode;

src/openalpr/alpr_impl.h

@@ -78,7 +78,7 @@ class AlprImpl
 class PlateDispatcher
 {
   public:
-    PlateDispatcher(vector<Rect> plateRegions, cv::Mat* image, 
+    PlateDispatcher(vector<PlateRegion> plateRegions, cv::Mat* image, 
 		    Config* config,
 		    StateIdentifier* stateIdentifier,
 		    OCR* ocr,
@@ -113,11 +113,11 @@ class PlateDispatcher
       mMutex.unlock();
       return plateAvailable;
     }
-    Rect nextPlate()
+    PlateRegion nextPlate()
     {
       tthread::lock_guard<tthread::mutex> guard(mMutex);
       
-      Rect plateRegion = plateRegions[plateRegions.size() - 1];
+      PlateRegion plateRegion = plateRegions[plateRegions.size() - 1];
       plateRegions.pop_back();
       
       return plateRegion;
@@ -147,7 +147,7 @@ class PlateDispatcher
     
     tthread::mutex mMutex;
     cv::Mat* frame;
-    vector<Rect> plateRegions;
+    vector<PlateRegion> plateRegions;
     vector<AlprResult> recognitionResults;
 
 };

src/openalpr/regiondetector.cpp

@@ -57,19 +57,19 @@ bool RegionDetector::isLoaded()
   return this->loaded;
 }
 
-vector<Rect> RegionDetector::detect(Mat frame)
+vector<PlateRegion> RegionDetector::detect(Mat frame)
 {
 
   Mat frame_gray;
   cvtColor( frame, frame_gray, CV_BGR2GRAY );
 
-  vector<Rect> regionsOfInterest = doCascade(frame_gray);
+  vector<PlateRegion> regionsOfInterest = doCascade(frame_gray);
 
   return regionsOfInterest;
 }
 
 /** @function detectAndDisplay */
-vector<Rect> RegionDetector::doCascade(Mat frame)
+vector<PlateRegion> RegionDetector::doCascade(Mat frame)
 {
   //float scale_factor = 1;
   int w = frame.size().width;
@@ -116,6 +116,28 @@ vector<Rect> RegionDetector::doCascade(Mat frame)
     plates[i].height = plates[i].height / scale_factor;
   }
 
-  return plates;
+  vector<PlateRegion> orderedRegions = aggregateRegions(plates);
+  
+  return orderedRegions;
 
 }
+
+vector<PlateRegion> RegionDetector::aggregateRegions(vector<Rect> regions)
+{
+  // Combines overlapping regions into a parent->child order.
+  // The largest regions will be parents, and they will have children if they are within them.
+  // This way, when processing regions later, we can process the parents first, and only delve into the children
+  // If there was no plate match.  Otherwise, we would process everything and that would be wasteful.
+  
+  vector<PlateRegion> orderedRegions;
+  
+  // For now, just return a full list with no children, so I can get the plumbing sorted.
+  for (int i = 0; i < regions.size(); i++)
+  {
+    PlateRegion newRegion;
+    newRegion.rect = regions[i];
+    orderedRegions.push_back(newRegion);
+  }
+  
+  return orderedRegions;
+}

src/openalpr/regiondetector.h

@@ -33,6 +33,12 @@
 #include "support/timing.h"
 #include "constants.h"
 
+struct PlateRegion
+{
+  Rect rect;
+  vector<PlateRegion> children;
+};
+
 class RegionDetector
 {
 
@@ -41,7 +47,7 @@ class RegionDetector
     virtual ~RegionDetector();
 
     bool isLoaded();
-    vector<Rect> detect(Mat frame);
+    vector<PlateRegion> detect(Mat frame);
 
   private:
     Config* config;
@@ -51,8 +57,9 @@ class RegionDetector
 
     bool loaded;
 
-    vector<Rect> doCascade(Mat frame);
+    vector<PlateRegion> doCascade(Mat frame);
 
+    vector<PlateRegion> aggregateRegions(vector<Rect> regions);
 };
 
 #endif // REGIONDETECTOR_H