OpenCV  3.3.0
Open Source Computer Vision
Pyramids.cpp

An example using pyrDown and pyrUp functions

using namespace cv;
Mat src, dst, tmp;
const char* window_name = "Pyramids Demo";
int main( void )
{
printf( "\n Zoom In-Out demo \n " );
printf( "------------------ \n" );
printf( " * [u] -> Zoom in \n" );
printf( " * [d] -> Zoom out \n" );
printf( " * [ESC] -> Close program \n \n" );
src = imread( "../data/chicky_512.png" ); // Loads the test image
if( src.empty() )
{ printf(" No data! -- Exiting the program \n");
return -1; }
tmp = src;
dst = tmp;
imshow( window_name, dst );
for(;;)
{
char c = (char)waitKey(0);
if( c == 27 )
{ break; }
if( c == 'u' )
{ pyrUp( tmp, dst, Size( tmp.cols*2, tmp.rows*2 ) );
printf( "** Zoom In: Image x 2 \n" );
}
else if( c == 'd' )
{ pyrDown( tmp, dst, Size( tmp.cols/2, tmp.rows/2 ) );
printf( "** Zoom Out: Image / 2 \n" );
}
imshow( window_name, dst );
tmp = dst;
}
return 0;
}