在Xcode中使用squares.cpp文件时遇到问题

Question

我使用了我从OpenCV网站下载的square.cpp文件，在Xcode中。它给出了错误参考点是雄心勃勃的。

请告诉我如何解决这个问题。如果我的问题不清楚，请告诉我。提前谢谢

    using namespace cv;

    using namespace std;

int thresh = 50, N = 11;
const char* wndname = "Square Detection Demo";

static void help()
{
    cout <<
    "\nA program using pyramid scaling, Canny, contours, contour simpification and\n"
    "memory storage (it's got it all folks) to find\n"
    "squares in a list of images pic1-6.png\n"
    "Returns sequence of squares detected on the image.\n"
    "the sequence is stored in the specified memory storage\n"
    "Call:\n"
    "./squares\n"
    "Using OpenCV version %s\n" << CV_VERSION << "\n" << endl;
}



// helper function:
// finds a cosine of angle between vectors
// from pt0->pt1 and from pt0->pt2
static double angle( Point pt1, Point pt2, Point pt0 )
{
    double dx1 = pt1.x - pt0.x;
    double dy1 = pt1.y - pt0.y;
    double dx2 = pt2.x - pt0.x;
    double dy2 = pt2.y - pt0.y;
    return (dx1*dx2 + dy1*dy2)/sqrt((dx1*dx1 + dy1*dy1)*(dx2*dx2 + dy2*dy2) + 1e-10);
}

// returns sequence of squares detected on the image.
// the sequence is stored in the specified memory storage
static void findSquares( const Mat& image, vector<vector<Point> >& squares )
{

        squares.clear();

        Mat pyr, timg, gray0(image.size(), CV_8U), gray;

        // down-scale and upscale the image to filter out the noise
        pyrDown(image, pyr, Size(image.cols/2, image.rows/2));
        pyrUp(pyr, timg, image.size());
        vector<vector<Point> > contours;

        // find squares in every color plane of the image
        for( int c = 0; c < 3; c++ )
        {
            int ch[] = {c, 0};
            mixChannels(&timg, 1, &gray0, 1, ch, 1);

            // try several threshold levels
            for( int l = 0; l < N; l++ )
            {
                // hack: use Canny instead of zero threshold level.
                // Canny helps to catch squares with gradient shading
                if( l == 0 )
                {
                    // apply Canny. Take the upper threshold from slider
                    // and set the lower to 0 (which forces edges merging)
                    Canny(gray0, gray, 0, thresh, 5);
                    // dilate canny output to remove potential
                    // holes between edge segments
                    dilate(gray, gray, Mat(), Point(-1,-1));
                }
                else
                {
                    // apply threshold if l!=0:
                    //     tgray(x,y) = gray(x,y) < (l+1)*255/N ? 255 : 0
                    gray = gray0 >= (l+1)*255/N;
                }

                // find contours and store them all as a list
                findContours(gray, contours, CV_RETR_LIST, CV_CHAIN_APPROX_SIMPLE);

                vector<Point> approx;

                // test each contour
                for( size_t i = 0; i < contours.size(); i++ )
                {
                    // approximate contour with accuracy proportional
                    // to the contour perimeter
                    approxPolyDP(Mat(contours[i]), approx, arcLength(Mat(contours[i]), true)*0.02, true);

                    // square contours should have 4 vertices after approximation
                    // relatively large area (to filter out noisy contours)
                    // and be convex.
                    // Note: absolute value of an area is used because
                    // area may be positive or negative - in accordance with the
                    // contour orientation
                    if( approx.size() == 4 &&
                       fabs(contourArea(Mat(approx))) > 1000 &&
                       isContourConvex(Mat(approx)) )
                    {
                        double maxCosine = 0;

                        for( int j = 2; j < 5; j++ )
                        {
                            // find the maximum cosine of the angle between joint edges
                            double cosine = fabs(angle(approx[j%4], approx[j-2], approx[j-1]));
                            maxCosine = MAX(maxCosine, cosine);
                        }

                        // if cosines of all angles are small
                        // (all angles are ~90 degree) then write quandrange
                        // vertices to resultant sequence
                        if( maxCosine < 0.3 )
                            squares.push_back(approx);
                    }
                }
            }
        }
    }


    // the function draws all the squares in the image
    static void drawSquares( Mat& image, const vector<vector<Point> >& squares )
    {
        for( size_t i = 0; i < squares.size(); i++ )
        {
            const Point* p = &squares[i][0];
            int n = (int)squares[i].size();
            polylines(image, &p, &n, 1, true, Scalar(0,255,0), 3, CV_AA);
        }

        imshow(wndname, image);
    }


    int main(int argc, char** argv)
    {
        static const char* names[] = { "pic1.png", "pic2.png", "pic3.png",
            "pic4.png", "pic5.png", "pic6.png", 0 };
        help();
        namedWindow( wndname, 1 );
        vector<vector<Point> > squares;

        for( int i = 0; names[i] != 0; i++ )
        {
            Mat image = imread(names[i], 1);
            if( image.empty() )
            {
                cout << "Couldn't load " << names[i] << endl;
                continue;
            }

            findSquares(image, squares);
            drawSquares(image, squares);

            int c = waitKey();
            if( (char)c == 27 )
                break;
        }

        return 0;
    }