目标：
基于OpenCV的函数cv::copyMakeBorder给图像添加边框
函数简介：
copyMakeBorder( src, dst, top, bottom, left, right, borderType, value );
参数:
src: 原图像
dst: 目标图像
top, bottom, left, right: 每一个边界方向上像素的宽度.在这里使用图像原始大小的 5% .
borderType:边框的类型 。当前例子中位纯色或者边界的复制.
value: 如果borderType 设置位 BORDER_CONSTANT, 这个将作为边框的颜色.
边框的类型
1）纯色边框
BORDER_CONSTANT，边框设置位某种单一的颜色，比如黑色
2）图像边界扩展
BORDER_REPLICATE，复制原图的边界进行扩展
代码
/**
* @file copyMakeBorder_demo.cpp
* @brief Sample code that shows the functionality of copyMakeBorder
* @author OpenCV team
*/
#include "opencv2/imgproc.hpp"
#include "opencv2/imgcodecs.hpp"
#include "opencv2/highgui.hpp"
using namespace cv;
//![variables]
Mat src, dst;
int top, bottom, left, right;
int borderType;
const char* window_name = "copyMakeBorder Demo";
RNG rng(12345);
//![variables]
/**
* @function main
*/
int main( int, char** argv )
{
int c;
//![load]
src = imread( argv[1], IMREAD_COLOR ); // Load an image
if( src.empty() )
{
printf(" No data entered, please enter the path to an image file \n");
return -1;
}
//![load]
/// Brief how-to for this program
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");
//![create_window]
namedWindow( window_name, WINDOW_AUTOSIZE );
//![create_window]
//![init_arguments]
/// Initialize arguments for the filter
top = (int) (0.05*src.rows); bottom = (int) (0.05*src.rows);
left = (int) (0.05*src.cols); right = (int) (0.05*src.cols);
//![init_arguments]
dst = src;
imshow( window_name, dst );
for(;;)
{
//![check_keypress]
c = waitKey(500);
if( (char)c == 27 )
{ break; }
else if( (char)c == 'c' )
{ borderType = BORDER_CONSTANT; }
else if( (char)c == 'r' )
{ borderType = BORDER_REPLICATE; }
//![check_keypress]
//![update_value]
Scalar value( rng.uniform(0, 255), rng.uniform(0, 255), rng.uniform(0, 255) );
//![update_value]
//![copymakeborder]
copyMakeBorder( src, dst, top, bottom, left, right, borderType, value );
//![copymakeborder]
//![display]
imshow( window_name, dst );
//![display]
}
return 0;
}
效果
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持找一找教程网。
