/*
Calculates the transfer error between a point and its correspondence for
a given homography, i.e. for a point x, it's correspondence x', and
homography H, computes d(x', Hx)^2.
@param pt a point
@param mpt pt's correspondence
@param H a homography matrix
@return Returns the transfer error between pt and mpt given H
*/
double homog_xfer_err( CvPoint2D64f pt, CvPoint2D64f mpt, CvMat* H )
{
CvPoint2D64f xpt = persp_xform_pt( pt, H );//pt经变换矩阵H变换后的点xpt,即H乘以x对应的向量
return sqrt( dist_sq_2D( xpt, mpt ) );//两点间距离的平方
}
/*
Calculates the transfer error between a point and its correspondence for
a given homography, i.e. for a point x, it's correspondence x', and
homography H, computes d(x', Hx)^2.
@param pt a point
@param mpt pt's correspondence
@param H a homography matrix
@return Returns the transfer error between pt and mpt given H
*/
double homog_xfer_err( CvPoint2D64f pt, CvPoint2D64f mpt, CvMat* H )
{
CvPoint2D64f xpt = persp_xform_pt( pt, H );
return sqrt( dist_sq_2D( xpt, mpt ) );
}
