Opencv图像处理之图像增加边框

 #include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/imgcodecs.hpp"
#include "opencv2/highgui/highgui.hpp"
#include <stdlib.h>
#include <stdio.h>
using namespace cv;
Mat src, dst;
int top, bottom, left, right;
int borderType;
const char* window_name = "copyMakeBorder Demo";
RNG rng(12345);
int main( int, char** argv )
{
 int c;
 src = imread( argv[1] );
 if( src.empty() )
  {
   printf(" No data entered, please enter the path to an image file \n");
   return -1;
  }
 printf( "\n \t copyMakeBorder Demo: \n" );
 printf( "\t -------------------- \n" );
 printf( " ** Press 'c' to set the border to a random constant value \n");
 printf( " ** Press 'r' to set the border to be replicated \n");
 printf( " ** Press 'ESC' to exit the program \n");
 namedWindow( window_name, WINDOW_AUTOSIZE );
 top = (int) (0.05*src.rows); bottom = (int) (0.05*src.rows);
 left = (int) (0.05*src.cols); right = (int) (0.05*src.cols);
 dst = src;
 imshow( window_name, dst );
 for(;;)
    {
     c = waitKey(500);
     if( (char)c == 27 )
      { break; }
     else if( (char)c == 'c' )
      { borderType = BORDER_CONSTANT; }
     else if( (char)c == 'r' )
      { borderType = BORDER_REPLICATE; }
     Scalar value( rng.uniform(0, 255), rng.uniform(0, 255), rng.uniform(0, 255) );
     copyMakeBorder( src, dst, top, bottom, left, right, borderType, value );
     imshow( window_name, dst );
    }
 return 0;
}