Enhance cv::TickMeter to be able to get the last ellapsed time

modules/core/include/opencv2/core/utility.hpp

@@ -309,11 +309,12 @@ public:
     //! stops counting ticks.
     CV_WRAP void stop()
     {
-        int64 time = cv::getTickCount();
+        const int64 time = cv::getTickCount();
         if (startTime == 0)
             return;
         ++counter;
-        sumTime += (time - startTime);
+        lastTime = time - startTime;
+        sumTime += lastTime;
         startTime = 0;
     }
 
@@ -336,11 +337,35 @@ public:
     }
 
     //! returns passed time in seconds.
-    CV_WRAP double getTimeSec()   const
+    CV_WRAP double getTimeSec() const
     {
         return (double)getTimeTicks() / getTickFrequency();
     }
 
+    //! returns counted ticks of the last iteration.
+    CV_WRAP int64 getLastTimeTicks() const
+    {
+        return lastTime;
+    }
+
+    //! returns passed time of the last iteration in microseconds.
+    CV_WRAP double getLastTimeMicro() const
+    {
+        return getLastTimeMilli()*1e3;
+    }
+
+    //! returns passed time of the last iteration in milliseconds.
+    CV_WRAP double getLastTimeMilli() const
+    {
+        return getLastTimeSec()*1e3;
+    }
+
+    //! returns passed time of the last iteration in seconds.
+    CV_WRAP double getLastTimeSec() const
+    {
+        return (double)getLastTimeTicks() / getTickFrequency();
+    }
+
     //! returns internal counter value.
     CV_WRAP int64 getCounter() const
     {
@@ -373,15 +398,17 @@ public:
     //! resets internal values.
     CV_WRAP void reset()
     {
-        startTime = 0;
-        sumTime = 0;
         counter = 0;
+        sumTime = 0;
+        startTime = 0;
+        lastTime = 0;
     }
 
 private:
     int64 counter;
     int64 sumTime;
     int64 startTime;
+    int64 lastTime;
 };
 
 /** @brief output operator

samples/cpp/tutorial_code/snippets/core_various.cpp

@@ -78,6 +78,7 @@ int main()
             tm.start();
             // do something ...
             tm.stop();
+            cout << "Last iteration: " << tm.getLastTimeSec() << endl;
         }
         cout << "Average time per iteration in seconds: " << tm.getAvgTimeSec() << endl;
         cout << "Average FPS: " << tm.getFPS() << endl;