macOS Sierra上Opencv的安装与使用

安装cmake
brew install cmake
安装OpenCV
 brew install opencv
//opencv升级
# brew upgrade opencv
配置OpenCV环境: vi /etc/profile添加

PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/Cellar/opencv/3.4.1_2/lib/pkgconfig 

export PKG_CONFIG_PATH  

export LD_LIBRARY_PATH=/usr/local/Cellar/opencv/3.4.1_2/bin:SLD_LIBRARY_PATH  

export PATH=${PATH}:/usr/local/Cellar/opencv/3.4.1_2/lib 

执行:source /etc/profile
重启电脑  

4.测试demo
<1>.test.cpp
   #include <opencv2/highgui.hpp>
#include <opencv2/opencv.hpp>  

using namespace cv;  

int main(int argc, char** argv)
{
  //加载图片路径
  Mat img = imread("moon.jpeg", CV_LOAD_IMAGE_UNCHANGED);  

  if(img.empty())
  {
    fprintf(stderr, "请输入正确的图片路径\n");
    return -1;
  }  

  Mat gray;
  cvtColor(img,gray,CV_BGR2GRAY);  

  //jpeg格式转换为png格式图片
  if( ! imwrite("image_copy.png", img) )
  {
    fprintf(stderr, "转换写入图片失败.\n");
  }  

  imshow("显示图片", img);
  waitKey(0);  

  return 0;
}  

<2>.Makefile 注意：第2行和第4行开头是 Tab键，不是空格键。
test:test.cpp
    g++ -o test test.cpp `pkg-config --libs opencv` `pkg-config --cflags opencv`   

clean:
    rm test