www.pudn.com > OpenCV-Intel.zip > cvcamshift.cpp


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#include "_cv.h" 
 
 
/*F/////////////////////////////////////////////////////////////////////////////////////// 
//    Name:    cvMeanShift 
//    Purpose: MeanShift algorithm 
//    Context: 
//    Parameters: 
//      imgProb     - 2D object probability distribution 
//      windowIn    - CvRect of CAMSHIFT Window intial size 
//      numIters    - If CAMSHIFT iterates this many times, stop 
//      windowOut   - Location, height and width of converged CAMSHIFT window 
//      len         - If != NULL, return equivalent len 
//      width       - If != NULL, return equivalent width 
//      itersUsed   - Returns number of iterations CAMSHIFT took to converge 
//    Returns: 
//      The function itself returns the area found 
//    Notes: 
//F*/ 
CV_IMPL int 
cvMeanShift( const void* imgProb, CvRect windowIn, 
             CvTermCriteria criteria, CvConnectedComp* comp ) 
{ 
    CvMoments moments; 
    int    i = 0, eps; 
    CvMat  stub, *mat = (CvMat*)imgProb; 
    CvMat  cur_win; 
    CvRect cur_rect = windowIn; 
 
    CV_FUNCNAME( "cvMeanShift" ); 
 
    if( comp ) 
        comp->rect = windowIn; 
 
    moments.m00 = moments.m10 = moments.m01 = 0; 
 
    __BEGIN__; 
 
    CV_CALL( mat = cvGetMat( mat, &stub )); 
 
    if( CV_MAT_CN( mat->type ) > 1 ) 
        CV_ERROR( CV_BadNumChannels, cvUnsupportedFormat ); 
 
    if( windowIn.height <= 0 || windowIn.width <= 0 ) 
        CV_ERROR( CV_StsBadArg, "Input window has non-positive sizes" ); 
 
    if( windowIn.x < 0 || windowIn.x + windowIn.width > mat->cols || 
        windowIn.y < 0 || windowIn.y + windowIn.height > mat->rows ) 
        CV_ERROR( CV_StsBadArg, "Initial window is not inside the image ROI" ); 
 
    CV_CALL( criteria = cvCheckTermCriteria( criteria, 1., 100 )); 
 
    eps = cvRound( criteria.epsilon * criteria.epsilon ); 
 
    for( i = 0; i < criteria.max_iter; i++ ) 
    { 
        int dx, dy, nx, ny; 
        double inv_m00; 
 
        CV_CALL( cvGetSubRect( mat, &cur_win, cur_rect ));  
        CV_CALL( cvMoments( &cur_win, &moments )); 
 
        /* Calculating center of mass */ 
        if( fabs(moments.m00) < DBL_EPSILON ) 
            break; 
 
        inv_m00 = moments.inv_sqrt_m00*moments.inv_sqrt_m00; 
        dx = cvRound( moments.m10 * inv_m00 - windowIn.width*0.5 ); 
        dy = cvRound( moments.m01 * inv_m00 - windowIn.height*0.5 ); 
 
        nx = cur_rect.x + dx; 
        ny = cur_rect.y + dy; 
 
        if( nx < 0 ) 
            nx = 0; 
        else if( nx + cur_rect.width > mat->cols ) 
            nx = mat->cols - cur_rect.width; 
 
        if( ny < 0 ) 
            ny = 0; 
        else if( ny + cur_rect.height > mat->rows ) 
            ny = mat->rows - cur_rect.height; 
 
        dx = nx - cur_rect.x; 
        dy = ny - cur_rect.y; 
        cur_rect.x = nx; 
        cur_rect.y = ny; 
 
        /* Check for coverage centers mass & window */ 
        if( dx*dx + dy*dy < eps ) 
            break; 
    } 
 
    __END__; 
 
    if( comp ) 
    { 
        comp->rect = cur_rect; 
        comp->area = (float)moments.m00; 
    } 
 
    return i; 
} 
 
 
/*F/////////////////////////////////////////////////////////////////////////////////////// 
//    Name:    cvCamShift 
//    Purpose: CAMSHIFT algorithm 
//    Context: 
//    Parameters: 
//      imgProb     - 2D object probability distribution 
//      windowIn    - CvRect of CAMSHIFT Window intial size 
//      criteria    - criteria of stop finding window 
//      windowOut   - Location, height and width of converged CAMSHIFT window 
//      orientation - If != NULL, return distribution orientation 
//      len         - If != NULL, return equivalent len 
//      width       - If != NULL, return equivalent width 
//      area        - sum of all elements in result window 
//      itersUsed   - Returns number of iterations CAMSHIFT took to converge 
//    Returns: 
//      The function itself returns the area found 
//    Notes: 
//F*/ 
CV_IMPL int 
cvCamShift( const void* imgProb, CvRect windowIn, 
            CvTermCriteria criteria, 
            CvConnectedComp* _comp, 
            CvBox2D* box ) 
{ 
    const int TOLERANCE = 10; 
    CvMoments moments; 
    double m00 = 0, m10, m01, mu20, mu11, mu02, inv_m00; 
    double a, b, c, xc, yc; 
    double rotate_a, rotate_c; 
    double theta = 0, square; 
    double cs, sn; 
    double length = 0, width = 0; 
    int itersUsed = 0; 
    CvConnectedComp comp; 
    CvMat  cur_win, stub, *mat = (CvMat*)imgProb; 
 
    CV_FUNCNAME( "cvCamShift" ); 
 
    comp.rect = windowIn; 
 
    __BEGIN__; 
 
    CV_CALL( mat = cvGetMat( mat, &stub )); 
 
    CV_CALL( itersUsed = cvMeanShift( mat, windowIn, criteria, &comp )); 
    windowIn = comp.rect; 
 
    windowIn.x -= TOLERANCE; 
    if( windowIn.x < 0 ) 
        windowIn.x = 0; 
 
    windowIn.y -= TOLERANCE; 
    if( windowIn.y < 0 ) 
        windowIn.y = 0; 
 
    windowIn.width += 2 * TOLERANCE; 
    if( windowIn.x + windowIn.width > mat->width ) 
        windowIn.width = mat->width - windowIn.x; 
 
    windowIn.height += 2 * TOLERANCE; 
    if( windowIn.y + windowIn.height > mat->height ) 
        windowIn.height = mat->height - windowIn.y; 
 
    CV_CALL( cvGetSubRect( mat, &cur_win, windowIn )); 
 
    /* Calculating moments in new center mass */ 
    CV_CALL( cvMoments( &cur_win, &moments )); 
 
    m00 = moments.m00; 
    m10 = moments.m10; 
    m01 = moments.m01; 
    mu11 = moments.mu11; 
    mu20 = moments.mu20; 
    mu02 = moments.mu02; 
 
    if( fabs(m00) < DBL_EPSILON ) 
        EXIT; 
 
    inv_m00 = 1. / m00; 
    xc = cvRound( m10 * inv_m00 + windowIn.x ); 
    yc = cvRound( m01 * inv_m00 + windowIn.y ); 
    a = mu20 * inv_m00; 
    b = mu11 * inv_m00; 
    c = mu02 * inv_m00; 
 
    /* Calculating width & height */ 
    square = sqrt( 4 * b * b + (a - c) * (a - c) ); 
 
    /* Calculating orientation */ 
    theta = atan2( 2 * b, a - c + square ); 
 
    /* Calculating width & length of figure */ 
    cs = cos( theta ); 
    sn = sin( theta ); 
 
    rotate_a = cs * cs * mu20 + 2 * cs * sn * mu11 + sn * sn * mu02; 
    rotate_c = sn * sn * mu20 - 2 * cs * sn * mu11 + cs * cs * mu02; 
    length = sqrt( rotate_a * inv_m00 ) * 4; 
    width = sqrt( rotate_c * inv_m00 ) * 4; 
 
    /* In case, when tetta is 0 or 1.57... the Length & Width may be exchanged */ 
    if( length < width ) 
    { 
        double t; 
         
        CV_SWAP( length, width, t ); 
        CV_SWAP( cs, sn, t ); 
        theta = CV_PI*0.5 - theta; 
    } 
 
    /* Saving results */ 
    if( _comp || box ) 
    { 
        int t0, t1; 
        int _xc = cvRound( xc ); 
        int _yc = cvRound( yc ); 
 
        t0 = cvRound( fabs( length * cs )); 
        t1 = cvRound( fabs( width * sn )); 
 
        t0 = MAX( t0, t1 ) + 2; 
        comp.rect.width = MIN( t0, (mat->width - _xc) * 2 ); 
 
        t0 = cvRound( fabs( length * sn )); 
        t1 = cvRound( fabs( width * cs )); 
 
        t0 = MAX( t0, t1 ) + 2; 
        comp.rect.height = MIN( t0, (mat->height - _yc) * 2 ); 
 
        comp.rect.x = MAX( 0, _xc - comp.rect.width / 2 ); 
        comp.rect.y = MAX( 0, _yc - comp.rect.height / 2 ); 
 
        comp.rect.width = MIN( mat->width - comp.rect.x, comp.rect.width ); 
        comp.rect.height = MIN( mat->height - comp.rect.y, comp.rect.height ); 
        comp.area = (float) m00; 
    } 
 
    __END__; 
 
    if( _comp ) 
        *_comp = comp; 
     
    if( box ) 
    { 
        box->size.height = (float)length; 
        box->size.width = (float)width; 
        box->angle = (float) theta; 
        box->center = cvPoint2D32f( comp.rect.x + comp.rect.width*0.5f, 
                                    comp.rect.y + comp.rect.height*0.5f); 
    } 
 
    return itersUsed; 
} 
 
/* End of file. */