Install homebrew

Type the following directions to install homebrew

ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Install OpenCV

After installing homebrew, we just need to type the following direction to install OpenCV

brew install opencv

It will not always works well. There may be kind of mistakes and I just encounter the such in the process. I just could not finish the installation of libpng, and I found that it was prevented by the man's trigger. The file man5 has been already allocated by other programs with the permission admin, so I used sudo chown $USER man5 to solve this problem. And then I went on with the instruction of brew link libpng.

Here, OpenCV has already been installed.

Settings and make a demo

Now All the dylibs is in /usr/local/lib, we need add them to our projects.

• First, we new a command line project in Xcode.
• Second, we left tap the Project and choose Add Files to ....

• Thirdly, we type Command + Shift + G to type the directory of our dylibs as above /usr/local/lib.

• Fourthly, choose all the dylibs under this directory and click Add.
• Fifthly, we click the settings and choose Target, select All option on the right side and type Header Search Path in the search. We just add these two lines in this section.

/usr/local/include
/usr/local/include/opencv

• Likewise, we also add /usr/local/lib to the Library Search Path
• Finally, type the following code in your main.cpp, see how it works!

#include <opencv2/opencv.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv/cvaux.hpp>

using namespace cv;

int main(int argc, const char * argv[])
{

    VideoCapture cap(0);
    if(!cap.isOpened()) {
        return -1;
    }

    Mat edges;
    namedWindow("Source", 1);
    for(;;) {
        Mat frame;
        cap >> frame;
        //resize(frame, frame, Size(320, 320));

        pyrDown(frame, frame);
        cvtColor(frame, frame, CV_BGR2GRAY);
        GaussianBlur(frame, frame, Size(7, 7), 1.5, 1.5);
        imshow("Source", frame);
        if(waitKey(30) >= 0)
            break;
    }

    return 0;
}