Added 02 cpp sample files for tutorials: remap and Geometric Transformations (warpAffine and Rotation2D)

samples/cpp/tutorial_code/ImgTrans/Geometric_Transforms_Demo.cpp

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+/**
+ * @function Geometric_Transforms_Demo.cpp
+ * @brief Demo code for Geometric Transforms
+ * @author OpenCV team
+ */
+
+#include "opencv2/highgui/highgui.hpp"
+#include "opencv2/imgproc/imgproc.hpp"
+#include <iostream>
+#include <stdio.h>
+
+using namespace cv;
+using namespace std;
+
+/// Global variables
+char* source_window = "Source image";
+char* warp_window = "Warp";
+char* warp_rotate_window = "Warp + Rotate";
+
+/**
+ * @function main
+ */
+int main( int argc, char** argv )
+{
+  Point2f srcTri[3];
+  Point2f dstTri[3];
+
+  Mat rot_mat( 2, 3, CV_32FC1 );
+  Mat warp_mat( 2, 3, CV_32FC1 );
+  Mat src, warp_dst, warp_rotate_dst;
+
+  /// Load the image
+  src = imread( argv[1], 1 );
+
+  /// Set the dst image the same type and size as src  
+  warp_dst = Mat::zeros( src.rows, src.cols, src.type() );
+
+  /// Set your 3 points to calculate the  Affine Transform
+  srcTri[0] = Point2f( 0,0 );
+  srcTri[1] = Point2f( src.cols - 1, 0 );
+  srcTri[2] = Point2f( 0, src.rows - 1 );
+  
+  dstTri[0] = Point2f( src.cols*0.0, src.rows*0.33 );
+  dstTri[1] = Point2f( src.cols*0.85, src.rows*0.25 );
+  dstTri[2] = Point2f( src.cols*0.15, src.rows*0.7 );
+
+  /// Get the Affine Transform
+  warp_mat = getAffineTransform( srcTri, dstTri );
+
+  /// Apply the Affine Transform just found to the src image
+  warpAffine( src, warp_dst, warp_mat, warp_dst.size() );
+
+  /** Rotating the image after Warp */
+
+  /// Compute a rotation matrix with respect to the center of the image
+  Point center = Point( warp_dst.cols/2, warp_dst.rows/2 );
+  double angle = -50.0;
+  double scale = 0.6;
+
+  /// Get the rotation matrix with the specifications above
+  rot_mat = getRotationMatrix2D( center, angle, scale );
+
+  /// Rotate the warped image
+  warpAffine( warp_dst, warp_rotate_dst, rot_mat, warp_dst.size() );
+  
+
+  /// Show what you got
+  namedWindow( source_window, CV_WINDOW_AUTOSIZE );
+  imshow( source_window, src );
+
+  namedWindow( warp_window, CV_WINDOW_AUTOSIZE );
+  imshow( warp_window, warp_dst );
+
+  namedWindow( warp_rotate_window, CV_WINDOW_AUTOSIZE );
+  imshow( warp_rotate_window, warp_rotate_dst );
+
+  /// Wait until user exits the program
+  waitKey(0);
+
+  return 0;
+}

samples/cpp/tutorial_code/ImgTrans/Remap_Demo.cpp

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+/**
+ * @function Remap_Demo.cpp
+ * @brief Demo code for Remap
+ * @author Ana Huaman
+ */
+
+#include "opencv2/highgui/highgui.hpp"
+#include "opencv2/imgproc/imgproc.hpp"
+#include <iostream>
+#include <stdio.h>
+
+using namespace cv;
+
+/// Global variables
+Mat src, dst;
+Mat map_x, map_y;
+char* remap_window = "Remap demo";
+int ind = 0;
+
+/// Function Headers
+void update_map( void );
+
+/**
+ * @function main
+ */
+int main( int argc, char** argv )
+{
+  /// Load the image
+  src = imread( argv[1], 1 );
+
+  /// Create dst, map_x and map_y with the same size as src:
+  dst.create( src.size(), src.type() );
+  map_x.create( src.size(), CV_32FC1 );
+  map_y.create( src.size(), CV_32FC1 );
+  
+  /// Create window
+  namedWindow( remap_window, CV_WINDOW_AUTOSIZE );
+
+  /// Loop
+  while( true )
+  {
+    /// Each 1 sec. Press ESC to exit the program
+    int c = waitKey( 1000 );
+
+    if( (char)c == 27 )
+      { break; }
+
+    /// Update map_x & map_y. Then apply remap
+    update_map();
+    remap( src, dst, map_x, map_y, CV_INTER_LINEAR, BORDER_CONSTANT, Scalar(0, 0, 0) ); 
+
+    // Display results
+    imshow( remap_window, dst );
+  }
+  return 0;
+}
+
+/**
+ * @function update_map
+ * @brief Fill the map_x and map_y matrices with 4 types of mappings
+ */
+void update_map( void )
+{
+  ind = ind%4;
+
+  for( int j = 0; j < src.rows; j++ )
+    { for( int i = 0; i < src.cols; i++ )
+ 	 {
+           switch( ind )
+	     {   
+	     case 0:
+	       if( i > src.cols*0.25 && i < src.cols*0.75 && j > src.rows*0.25 && j < src.rows*0.75 )
+                 {
+	           map_x.at<float>(j,i) = 2*( i - src.cols*0.25 ) + 0.5 ;
+	           map_y.at<float>(j,i) = 2*( j - src.rows*0.25 ) + 0.5 ;
+	          }
+	       else
+		 { map_x.at<float>(j,i) = 0 ;
+	           map_y.at<float>(j,i) = 0 ;
+                 }
+                   break;
+	     case 1:
+	           map_x.at<float>(j,i) = i ;
+	           map_y.at<float>(j,i) = src.rows - j ;
+		   break;
+             case 2:
+	           map_x.at<float>(j,i) = src.cols - i ;
+	           map_y.at<float>(j,i) = j ;
+		   break;
+             case 3:
+	           map_x.at<float>(j,i) = src.cols - i ;
+	           map_y.at<float>(j,i) = src.rows - j ;
+		   break;
+             } // end of switch
+	 }
+    }
+  ind++;
+}