C++ Point2f::ddot方法代码示例

static Mat endpointError( const Mat_<Point2f>& flow1, const Mat_<Point2f>& flow2 )
{
    Mat result(flow1.size(), CV_32FC1);
    for ( int i = 0; i < flow1.rows; ++i )
    {
        for ( int j = 0; j < flow1.cols; ++j )
        {
            const Point2f u1 = flow1(i, j);
            const Point2f u2 = flow2(i, j);

            if ( isFlowCorrect(u1) && isFlowCorrect(u2) )
            {
                const Point2f diff = u1 - u2;
                result.at<float>(i, j) = sqrt((float)diff.ddot(diff)); //distance
            } else
                result.at<float>(i, j) = std::numeric_limits<float>::quiet_NaN();
        }
    }
    return result;
}

static int intersectConvexConvex_( const Point2f* P, int n, const Point2f* Q, int m,
                                   Point2f* result, float* _area )
{
    Point2f* result0 = result;
    // P has n vertices, Q has m vertices.
    int     a=0, b=0;       // indices on P and Q (resp.)
    Point2f Origin(0,0);
    tInFlag inflag=Unknown; // {Pin, Qin, Unknown}: which inside
    int     aa=0, ba=0;     // # advances on a & b indices (after 1st inter.)
    bool    FirstPoint=true;// Is this the first point? (used to initialize).
    Point2f p0;             // The first point.
    *result++ = Point2f(FLT_MAX, FLT_MAX);

    do
    {
        // Computations of key variables.
        int a1 = (a + n - 1) % n; // a-1, b-1 (resp.)
        int b1 = (b + m - 1) % m;

        Point2f A = P[a] - P[a1], B = Q[b] - Q[b1]; // directed edges on P and Q (resp.)

        int cross = areaSign( Origin, A, B );    // sign of z-component of A x B
        int aHB = areaSign( Q[b1], Q[b], P[a] ); // a in H(b).
        int bHA = areaSign( P[a1], P[a], Q[b] ); // b in H(A);

        // If A & B intersect, update inflag.
        Point2f p, q;
        int code = segSegInt( P[a1], P[a], Q[b1], Q[b], p, q );
        if( code == '1' || code == 'v' )
        {
            if( inflag == Unknown && FirstPoint )
            {
                aa = ba = 0;
                FirstPoint = false;
                p0 = p;
                *result++ = p;
            }
            inflag = inOut( p, inflag, aHB, bHA, result );
        }

        //-----Advance rules-----

        // Special case: A & B overlap and oppositely oriented.
        if( code == 'e' && A.ddot(B) < 0 )
        {
            addSharedSeg( p, q, result );
            return (int)(result - result0);
        }

        // Special case: A & B parallel and separated.
        if( cross == 0 && aHB < 0 && bHA < 0 )
            return (int)(result - result0);

        // Special case: A & B collinear.
        else if ( cross == 0 && aHB == 0 && bHA == 0 ) {
            // Advance but do not output point.
            if ( inflag == Pin )
                b = advance( b, &ba, m, inflag == Qin, Q[b], result );
            else
                a = advance( a, &aa, n, inflag == Pin, P[a], result );
        }

        // Generic cases.
        else if( cross >= 0 )
        {
            if( bHA > 0)
                a = advance( a, &aa, n, inflag == Pin, P[a], result );
            else
                b = advance( b, &ba, m, inflag == Qin, Q[b], result );
        }
        else
        {
            if( aHB > 0)
                b = advance( b, &ba, m, inflag == Qin, Q[b], result );
            else
                a = advance( a, &aa, n, inflag == Pin, P[a], result );
        }
        // Quit when both adv. indices have cycled, or one has cycled twice.
    }
    while ( ((aa < n) || (ba < m)) && (aa < 2*n) && (ba < 2*m) );

    // Deal with special cases: not implemented.
    if( inflag == Unknown )
    {
        // The boundaries of P and Q do not cross.
        // ...
    }

    int i, nr = (int)(result - result0);
    double area = 0;
    Point2f prev = result0[nr-1];
    for( i = 1; i < nr; i++ )
    {
        result0[i-1] = result0[i];
        area += (double)prev.x*result0[i].y - (double)prev.y*result0[i].x;
        prev = result0[i];
    }

    *_area = (float)(area*0.5);

//.........这里部分代码省略.........

bool CV_OptFlowTest::runSparse()
{    
    Mat prev = imread(string(ts->get_data_path()) + "optflow/rock_1.bmp", 0);
    Mat next = imread(string(ts->get_data_path()) + "optflow/rock_2.bmp", 0);

    if (prev.empty() || next.empty())
    {
        ts->set_failed_test_info( cvtest::TS::FAIL_INVALID_TEST_DATA );  
        return false;
    }

    Mat cprev, cnext;
    cvtColor(prev, cprev, CV_GRAY2BGR);
    cvtColor(next, cnext, CV_GRAY2BGR);

    vector<Point2f> prev_pts;
    vector<Point2f> next_ptsOpt;
    vector<Point2f> next_ptsAff;
    vector<uchar> status_Opt;
    vector<uchar> status_Aff;
    vector<float> error;
    vector<float> matrices;

    Size netSize(10, 10);
    Point2f center = Point(prev.cols/2, prev.rows/2);

    for(int i = 0 ; i < netSize.width; ++i)
        for(int j = 0 ; j < netSize.width; ++j)
        {
            Point2f p(i * float(prev.cols)/netSize.width, j * float(prev.rows)/netSize.height);
            prev_pts.push_back((p - center) * 0.5f + center);            
        }

    calcOpticalFlowPyrLK( prev, next, prev_pts, next_ptsOpt, status_Opt, error );
    calcAffineFlowPyrLK ( prev, next, prev_pts, next_ptsAff, status_Aff, error, matrices);

    const double expected_shift = 25;
    const double thres = 1;    
    for(size_t i = 0; i < prev_pts.size(); ++i)        
    {
        circle(cprev, prev_pts[i], 2, CV_RGB(255, 0, 0));               

        if (status_Opt[i])
        {            
            circle(cnext, next_ptsOpt[i], 2, CV_RGB(0, 0, 255));
            Point2f shift = prev_pts[i] - next_ptsOpt[i];
            
            double n = sqrt(shift.ddot(shift));
            if (fabs(n - expected_shift) > thres)
            {
                ts->set_failed_test_info(cvtest::TS::FAIL_MISMATCH);
                return false;
            }
        }

        if (status_Aff[i])
        {            
            circle(cnext, next_ptsAff[i], 4, CV_RGB(0, 255, 0));
            Point2f shift = prev_pts[i] - next_ptsAff[i];

            double n = sqrt(shift.ddot(shift));
            if (fabs(n - expected_shift) > thres)
            {
                ts->set_failed_test_info(cvtest::TS::FAIL_MISMATCH);
                return false;
            }
        }
        
    }
    
    /*namedWindow("P");  imshow("P", cprev);
    namedWindow("N"); imshow("N", cnext); 
    waitKey();*/
    
    return true;
}