c - OpenCV:尝试编译时出现 "Undefined symbols for architecture x86_64:"

Question

环境:操作系统:macOS，OpenCV:2.4.12

刚开始学习OpenCV，从书上记下一段代码，就是，

#include <opencv/highgui.h>

int main(int argc, char **argv) {
        int iscolor = -1;
        IplImage* img = cvLoadImage(argv[1], iscolor);
        cvNamedWindow("Example1", CV_WINDOW_AUTOSIZE);
        cvShowImage("Example1", img);
        cvWaitKey(0);

        cvReleaseImage(&img);
        cvDestroyWindow("Example1");
        return 0;
}

当我尝试使用此命令编译此代码时 - gcc opencv1.c -o opencv1，它显示错误并显示以下消息。

Undefined symbols for architecture x86_64:
  "_cvDestroyWindow", referenced from:
      _main in opencv1-78cabd.o
  "_cvLoadImage", referenced from:
      _main in opencv1-78cabd.o
  "_cvNamedWindow", referenced from:
      _main in opencv1-78cabd.o
  "_cvReleaseImage", referenced from:
      _main in opencv1-78cabd.o
  "_cvShowImage", referenced from:
      _main in opencv1-78cabd.o
  "_cvWaitKey", referenced from:
      _main in opencv1-78cabd.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

有人知道解决办法吗？

Answer 1

编译时需要包含OpenCV库，pkg-config可以提供帮助:

gcc `pkg-config --cflags opencv` `pkg-config --libs opencv` opencv1.c -o opencv1