Added cornerDetector_Demo.cpp sample for tutorial of cornerMinEigenVal and cornerEigenValsAndVecs

samples/cpp/tutorial_code/TrackingMotion/cornerDetector_Demo.cpp

+/**
+ * @function cornerDetector_Demo.cpp
+ * @brief Demo code for detecting corners using OpenCV built-in functions
+ * @author OpenCV team
+ */
+#include "opencv2/highgui/highgui.hpp"
+#include "opencv2/imgproc/imgproc.hpp"
+#include <iostream>
+#include <stdio.h>
+#include <stdlib.h>
+
+using namespace cv;
+using namespace std;
+
+/// Global variables
+Mat src, src_gray;
+Mat myHarris_dst; Mat myHarris_copy; Mat Mc;
+Mat myShiTomasi_dst; Mat myShiTomasi_copy; 
+
+int myShiTomasi_qualityLevel = 50;
+int myHarris_qualityLevel = 50;
+int max_qualityLevel = 100;
+
+double myHarris_minVal; double myHarris_maxVal;
+double myShiTomasi_minVal; double myShiTomasi_maxVal;
+
+RNG rng(12345);
+
+char* myHarris_window = "My Harris corner detector";
+char* myShiTomasi_window = "My Shi Tomasi corner detector";
+
+/// Function headers
+void myShiTomasi_function( int, void* );
+void myHarris_function( int, void* );
+
+/**
+ * @function main
+ */
+int main( int argc, char** argv )
+{
+  /// Load source image and convert it to gray
+  src = imread( argv[1], 1 );
+  cvtColor( src, src_gray, CV_BGR2GRAY );
+
+  /// Set some parameters
+  int blockSize = 3; int apertureSize = 3;
+
+  /// My Harris matrix -- Using cornerEigenValsAndVecs
+  myHarris_dst = Mat::zeros( src_gray.size(), CV_32FC(6) );
+  Mc = Mat::zeros( src_gray.size(), CV_32FC1 );
+
+  cornerEigenValsAndVecs( src_gray, myHarris_dst, blockSize, apertureSize, BORDER_DEFAULT );
+
+  /* calculate Mc */ 
+  for( int j = 0; j < src_gray.rows; j++ )
+     { for( int i = 0; i < src_gray.cols; i++ )
+          {
+            float lambda_1 = myHarris_dst.at<float>( j, i, 0 );
+            float lambda_2 = myHarris_dst.at<float>( j, i, 1 );
+            Mc.at<float>(j,i) = lambda_1*lambda_2 - 0.04*pow( ( lambda_1 + lambda_2 ), 2 );
+          }
+     }
+
+  minMaxLoc( Mc, &myHarris_minVal, &myHarris_maxVal, 0, 0, Mat() );
+  
+  /* Create Window and Trackbar */
+  namedWindow( myHarris_window, CV_WINDOW_AUTOSIZE );
+  createTrackbar( " Quality Level:", myHarris_window, &myHarris_qualityLevel, max_qualityLevel, myHarris_function );  
+  myHarris_function( 0, 0 );
+
+  /// My Shi-Tomasi -- Using cornerMinEigenVal
+  myShiTomasi_dst = Mat::zeros( src_gray.size(), CV_32FC1 );  
+  cornerMinEigenVal( src_gray, myShiTomasi_dst, blockSize, apertureSize, BORDER_DEFAULT );
+
+  minMaxLoc( myShiTomasi_dst, &myShiTomasi_minVal, &myShiTomasi_maxVal, 0, 0, Mat() );
+
+  /* Create Window and Trackbar */
+  namedWindow( myShiTomasi_window, CV_WINDOW_AUTOSIZE );   
+  createTrackbar( " Quality Level:", myShiTomasi_window, &myShiTomasi_qualityLevel, max_qualityLevel, myShiTomasi_function );  
+  myShiTomasi_function( 0, 0 );
+  
+  waitKey(0);
+  return(0);
+}
+
+/**
+ * @function myShiTomasi_function
+ */
+void myShiTomasi_function( int, void* )
+{
+  myShiTomasi_copy = src.clone();
+
+  if( myShiTomasi_qualityLevel < 1 ) { myShiTomasi_qualityLevel = 1; }
+
+  for( int j = 0; j < src_gray.rows; j++ )
+     { for( int i = 0; i < src_gray.cols; i++ )
+          {
+            if( myShiTomasi_dst.at<float>(j,i) > myShiTomasi_minVal + ( myShiTomasi_maxVal - myShiTomasi_minVal )*myShiTomasi_qualityLevel/max_qualityLevel )
+              { circle( myShiTomasi_copy, Point(i,j), 4, Scalar( rng.uniform(0,255), rng.uniform(0,255), rng.uniform(0,255) ), -1, 8, 0 ); }
+          }
+     }
+  imshow( myShiTomasi_window, myShiTomasi_copy );
+}
+
+/**
+ * @function myHarris_function
+ */
+void myHarris_function( int, void* )
+{
+  myHarris_copy = src.clone();
+
+  if( myHarris_qualityLevel < 1 ) { myHarris_qualityLevel = 1; }
+
+  for( int j = 0; j < src_gray.rows; j++ )
+     { for( int i = 0; i < src_gray.cols; i++ )
+          {
+            if( Mc.at<float>(j,i) > myHarris_minVal + ( myHarris_maxVal - myHarris_minVal )*myHarris_qualityLevel/max_qualityLevel )
+              { circle( myHarris_copy, Point(i,j), 4, Scalar( rng.uniform(0,255), rng.uniform(0,255), rng.uniform(0,255) ), -1, 8, 0 ); }
+          }
+     }
+  imshow( myHarris_window, myHarris_copy );
+}
+