. Image Pyramid

#include
#include <opencv2/imgproc.hpp>
#include <opencv2/imgcodecs.hpp>
#include <opencv2/highgui.hpp>

using namespace std;
using namespace cv;

const char* window_name = “Pyramids Demo”;

int main( int argc, char** argv )
{
cout << “\n Zoom In-Out demo \n "
“------------------ \n”
" * [i] -> Zoom in \n”
" * [o] -> Zoom out \n"
" * [ESC] -> Close program \n" << endl;

const char* filename = "/home/chang/projects/opencv_GPU_example/test.jpg";
// Loads an image
Mat src = imread( samples::findFile( filename ) );
// Check if image is loaded fine
if(src.empty()){
    printf(" Error opening image\n");
    printf(" Program Arguments: [image_name -- default chicky_512.png] \n");
    return EXIT_FAILURE;
}
for(;;)
{
    imshow( window_name, src );
    char c = (char)waitKey(0);
    if( c == 27 )
    { break; }
    else if( c == 'i' ) // 放大图片
    { pyrUp( src, src, Size( src.cols*2, src.rows*2 ) );
        printf( "** Zoom In: Image x 2 \n" );
    }
    else if( c == 'o' ) // 缩小图片
    { pyrDown( src, src, Size( src.cols/2, src.rows/2 ) );
        printf( "** Zoom Out: Image / 2 \n" );
    }
}
return EXIT_SUCCESS;

}