OpenCV实现给图片添加边框功能

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脚本之家。

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