OpenCV  4.1.2
Open Source Computer Vision
samples/cpp/tutorial_code/ImgProc/Smoothing/Smoothing.cpp

Sample code for simple filters

Smoothing_Tutorial_Result_Median_Filter.jpg
Sample screenshot

Check the corresponding tutorial for more details

#include <iostream>
using namespace std;
using namespace cv;
int DELAY_CAPTION = 1500;
int DELAY_BLUR = 100;
int MAX_KERNEL_LENGTH = 31;
Mat src; Mat dst;
char window_name[] = "Smoothing Demo";
int display_caption( const char* caption );
int display_dst( int delay );
int main( int argc, char ** argv )
{
namedWindow( window_name, WINDOW_AUTOSIZE );
const char* filename = argc >=2 ? argv[1] : "lena.jpg";
src = imread( samples::findFile( filename ), IMREAD_COLOR );
if (src.empty())
{
printf(" Error opening image\n");
printf(" Usage:\n %s [image_name-- default lena.jpg] \n", argv[0]);
return EXIT_FAILURE;
}
if( display_caption( "Original Image" ) != 0 )
{
return 0;
}
dst = src.clone();
if( display_dst( DELAY_CAPTION ) != 0 )
{
return 0;
}
if( display_caption( "Homogeneous Blur" ) != 0 )
{
return 0;
}
for ( int i = 1; i < MAX_KERNEL_LENGTH; i = i + 2 )
{
blur( src, dst, Size( i, i ), Point(-1,-1) );
if( display_dst( DELAY_BLUR ) != 0 )
{
return 0;
}
}
if( display_caption( "Gaussian Blur" ) != 0 )
{
return 0;
}
for ( int i = 1; i < MAX_KERNEL_LENGTH; i = i + 2 )
{
GaussianBlur( src, dst, Size( i, i ), 0, 0 );
if( display_dst( DELAY_BLUR ) != 0 )
{
return 0;
}
}
if( display_caption( "Median Blur" ) != 0 )
{
return 0;
}
for ( int i = 1; i < MAX_KERNEL_LENGTH; i = i + 2 )
{
medianBlur ( src, dst, i );
if( display_dst( DELAY_BLUR ) != 0 )
{
return 0;
}
}
if( display_caption( "Bilateral Blur" ) != 0 )
{
return 0;
}
for ( int i = 1; i < MAX_KERNEL_LENGTH; i = i + 2 )
{
bilateralFilter ( src, dst, i, i*2, i/2 );
if( display_dst( DELAY_BLUR ) != 0 )
{
return 0;
}
}
display_caption( "Done!" );
return 0;
}
int display_caption( const char* caption )
{
dst = Mat::zeros( src.size(), src.type() );
putText( dst, caption,
Point( src.cols/4, src.rows/2),
FONT_HERSHEY_COMPLEX, 1, Scalar(255, 255, 255) );
return display_dst(DELAY_CAPTION);
}
int display_dst( int delay )
{
imshow( window_name, dst );
int c = waitKey ( delay );
if( c >= 0 ) { return -1; }
return 0;
}