opencv/modules/contrib/src/ba.cpp

1112 lines
38 KiB
C++

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#include "precomp.hpp"
#include "opencv2/calib3d/calib3d.hpp"
namespace cv {
LevMarqSparse::LevMarqSparse()
{
A = B = W = Vis_index = X = prevP = P = deltaP = err = JtJ_diag = S = hX = NULL;
U = ea = V = inv_V_star = eb = Yj = NULL;
num_points = 0;
num_cams = 0;
}
LevMarqSparse::~LevMarqSparse()
{
clear();
}
LevMarqSparse::LevMarqSparse(int npoints, // number of points
int ncameras, // number of cameras
int nPointParams, // number of params per one point (3 in case of 3D points)
int nCameraParams, // number of parameters per one camera
int nErrParams, // number of parameters in measurement vector
// for 1 point at one camera (2 in case of 2D projections)
Mat& visibility, // visibility matrix. rows correspond to points, columns correspond to cameras
// 1 - point is visible for the camera, 0 - invisible
Mat& P0, // starting vector of parameters, first cameras then points
Mat& X_, // measurements, in order of visibility. non visible cases are skipped
TermCriteria criteria, // termination criteria
// callback for estimation of Jacobian matrices
void (CV_CDECL * fjac)(int i, int j, Mat& point_params,
Mat& cam_params, Mat& A, Mat& B, void* data),
// callback for estimation of backprojection errors
void (CV_CDECL * func)(int i, int j, Mat& point_params,
Mat& cam_params, Mat& estim, void* data),
void* data // user-specific data passed to the callbacks
)
{
A = B = W = Vis_index = X = prevP = P = deltaP = err = JtJ_diag = S = hX = NULL;
U = ea = V = inv_V_star = eb = Yj = NULL;
run(npoints, ncameras, nPointParams, nCameraParams, nErrParams, visibility,
P0, X_, criteria, fjac, func, data);
}
void LevMarqSparse::clear()
{
for( int i = 0; i < num_points; i++ )
{
for(int j = 0; j < num_cams; j++ )
{
CvMat* tmp = ((CvMat**)(A->data.ptr + i * A->step))[j];
if( tmp )
cvReleaseMat( &tmp );
tmp = ((CvMat**)(B->data.ptr + i * B->step))[j];
if( tmp )
cvReleaseMat( &tmp );
tmp = ((CvMat**)(W->data.ptr + j * W->step))[i];
if( tmp )
cvReleaseMat( &tmp );
}
}
cvReleaseMat( &A );
cvReleaseMat( &B );
cvReleaseMat( &W );
cvReleaseMat( &Vis_index);
for( int j = 0; j < num_cams; j++ )
{
cvReleaseMat( &U[j] );
}
delete U;
for( int j = 0; j < num_cams; j++ )
{
cvReleaseMat( &ea[j] );
}
delete ea;
//allocate V and inv_V_star
for( int i = 0; i < num_points; i++ )
{
cvReleaseMat(&V[i]);
cvReleaseMat(&inv_V_star[i]);
}
delete V;
delete inv_V_star;
for( int i = 0; i < num_points; i++ )
{
cvReleaseMat(&eb[i]);
}
delete eb;
for( int i = 0; i < num_points; i++ )
{
cvReleaseMat(&Yj[i]);
}
delete Yj;
cvReleaseMat(&X);
cvReleaseMat(&prevP);
cvReleaseMat(&P);
cvReleaseMat(&deltaP);
cvReleaseMat(&err);
cvReleaseMat(&JtJ_diag);
cvReleaseMat(&S);
cvReleaseMat(&hX);
}
//A params correspond to Cameras
//B params correspont to Points
//num_cameras - total number of cameras
//num_points - total number of points
//num_par_per_camera - number of parameters per camera
//num_par_per_point - number of parameters per point
//num_errors - number of measurements.
void LevMarqSparse::run( int num_points_, //number of points
int num_cams_, //number of cameras
int num_point_param_, //number of params per one point (3 in case of 3D points)
int num_cam_param_, //number of parameters per one camera
int num_err_param_, //number of parameters in measurement vector for 1 point at one camera (2 in case of 2D projections)
Mat& visibility, //visibility matrix . rows correspond to points, columns correspond to cameras
// 0 - point is visible for the camera, 0 - invisible
Mat& P0, //starting vector of parameters, first cameras then points
Mat& X_init, //measurements, in order of visibility. non visible cases are skipped
TermCriteria criteria_init,
void (*fjac_)(int i, int j, Mat& point_params, Mat& cam_params, Mat& A, Mat& B, void* data),
void (*func_)(int i, int j, Mat& point_params, Mat& cam_params, Mat& estim, void* data),
void* data_
) //termination criteria
{
clear();
func = func_; //assign evaluation function
fjac = fjac_; //assign jacobian
data = data_;
num_cams = num_cams_;
num_points = num_points_;
num_err_param = num_err_param_;
num_cam_param = num_cam_param_;
num_point_param = num_point_param_;
//compute all sizes
int Aij_width = num_cam_param;
int Aij_height = num_err_param;
int Bij_width = num_point_param;
int Bij_height = num_err_param;
int U_size = Aij_width;
int V_size = Bij_width;
int Wij_height = Aij_width;
int Wij_width = Bij_width;
//allocate memory for all Aij, Bij, U, V, W
//allocate num_points*num_cams matrices A
//Allocate matrix A whose elements are nointers to Aij
//if Aij is zero (point i is not visible in camera j) then A(i,j) contains NULL
A = cvCreateMat( num_points, num_cams, CV_32S /*pointer is stored here*/ );
B = cvCreateMat( num_points, num_cams, CV_32S /*pointer is stored here*/ );
W = cvCreateMat( num_cams, num_points, CV_32S /*pointer is stored here*/ );
Vis_index = cvCreateMat( num_points, num_cams, CV_32S /*integer index is stored here*/ );
cvSetZero( A );
cvSetZero( B );
cvSetZero( W );
cvSet( Vis_index, cvScalar(-1) );
//fill matrices A and B based on visibility
CvMat _vis = visibility;
int index = 0;
for( int i = 0; i < num_points; i++ )
{
for(int j = 0; j < num_cams; j++ )
{
if( ((int*)(_vis.data.ptr+ i * _vis.step))[j] )
{
((int*)(Vis_index->data.ptr + i * Vis_index->step))[j] = index;
index += num_err_param;
//create matrices Aij, Bij
CvMat* tmp = cvCreateMat( Aij_height, Aij_width, CV_64F );
((CvMat**)(A->data.ptr + i * A->step))[j] = tmp;
tmp = cvCreateMat( Bij_height, Bij_width, CV_64F );
((CvMat**)(B->data.ptr + i * B->step))[j] = tmp;
tmp = cvCreateMat( Wij_height, Wij_width, CV_64F );
((CvMat**)(W->data.ptr + j * W->step))[i] = tmp; //note indices i and j swapped
}
}
}
//allocate U
U = new CvMat* [num_cams];
for( int j = 0; j < num_cams; j++ )
{
U[j] = cvCreateMat( U_size, U_size, CV_64F );
}
//allocate ea
ea = new CvMat* [num_cams];
for( int j = 0; j < num_cams; j++ )
{
ea[j] = cvCreateMat( U_size, 1, CV_64F );
}
//allocate V and inv_V_star
V = new CvMat* [num_points];
inv_V_star = new CvMat* [num_points];
for( int i = 0; i < num_points; i++ )
{
V[i] = cvCreateMat( V_size, V_size, CV_64F );
inv_V_star[i] = cvCreateMat( V_size, V_size, CV_64F );
}
//allocate eb
eb = new CvMat* [num_points];
for( int i = 0; i < num_points; i++ )
{
eb[i] = cvCreateMat( V_size, 1, CV_64F );
}
//allocate Yj
Yj = new CvMat* [num_points];
for( int i = 0; i < num_points; i++ )
{
Yj[i] = cvCreateMat( Wij_height, Wij_width, CV_64F ); //Yij has the same size as Wij
}
//allocate matrix S
S = cvCreateMat( num_cams * num_cam_param, num_cams * num_cam_param, CV_64F);
JtJ_diag = cvCreateMat( num_cams * num_cam_param + num_points * num_point_param, 1, CV_64F );
//set starting parameters
CvMat _tmp_ = CvMat(P0);
prevP = cvCloneMat( &_tmp_ );
P = cvCloneMat( &_tmp_ );
deltaP = cvCloneMat( &_tmp_ );
//set measurements
_tmp_ = CvMat(X_init);
X = cvCloneMat( &_tmp_ );
//create vector for estimated measurements
hX = cvCreateMat( X->rows, X->cols, CV_64F );
//create error vector
err = cvCreateMat( X->rows, X->cols, CV_64F );
ask_for_proj();
//compute initial error
cvSub( X, hX, err );
prevErrNorm = cvNorm( err, 0, CV_L2 );
iters = 0;
criteria = criteria_init;
optimize();
}
void LevMarqSparse::ask_for_proj()
{
//given parameter P, compute measurement hX
int ind = 0;
for( int i = 0; i < num_points; i++ )
{
CvMat point_mat;
cvGetSubRect( P, &point_mat, cvRect( 0, num_cams * num_cam_param + num_point_param * i, 1, num_point_param ));
for( int j = 0; j < num_cams; j++ )
{
CvMat* Aij = ((CvMat**)(A->data.ptr + A->step * i))[j];
if( Aij ) //visible
{
CvMat cam_mat;
cvGetSubRect( P, &cam_mat, cvRect( 0, j * num_cam_param, 1, num_cam_param ));
CvMat measur_mat;
cvGetSubRect( hX, &measur_mat, cvRect( 0, ind * num_err_param, 1, num_err_param ));
Mat _point_mat(&point_mat), _cam_mat(&cam_mat), _measur_mat(&measur_mat);
func( i, j, _point_mat, _cam_mat, _measur_mat, data );
assert( ind*num_err_param == ((int*)(Vis_index->data.ptr + i * Vis_index->step))[j]);
ind+=1;
}
}
}
}
//iteratively asks for Jacobians for every camera_point pair
void LevMarqSparse::ask_for_projac() //should be evaluated at point prevP
{
// compute jacobians Aij and Bij
for( int i = 0; i < A->height; i++ )
{
CvMat point_mat;
cvGetSubRect( prevP, &point_mat, cvRect( 0, num_cams * num_cam_param + num_point_param * i, 1, num_point_param ));
CvMat** A_line = (CvMat**)(A->data.ptr + A->step * i);
CvMat** B_line = (CvMat**)(B->data.ptr + B->step * i);
for( int j = 0; j < A->width; j++ )
{
CvMat* Aij = A_line[j];
if( Aij ) //Aij is not zero
{
CvMat cam_mat;
cvGetSubRect( prevP, &cam_mat, cvRect( 0, j * num_cam_param, 1, num_cam_param ));
CvMat* Bij = B_line[j];
Mat _point_mat(&point_mat), _cam_mat(&cam_mat), _Aij(Aij), _Bij(Bij);
(*fjac)(i, j, _point_mat, _cam_mat, _Aij, _Bij, data);
}
}
}
}
void LevMarqSparse::optimize() //main function that runs minimization
{
bool done = false;
CvMat* YWt = cvCreateMat( num_cam_param, num_cam_param, CV_64F ); //this matrix used to store Yij*Wik'
CvMat* E = cvCreateMat( S->height, 1 , CV_64F ); //this is right part of system with S
while(!done)
{
// compute jacobians Aij and Bij
ask_for_projac();
//compute U_j and ea_j
for( int j = 0; j < num_cams; j++ )
{
cvSetZero(U[j]);
cvSetZero(ea[j]);
//summ by i (number of points)
for( int i = 0; i < num_points; i++ )
{
//get Aij
CvMat* Aij = ((CvMat**)(A->data.ptr + A->step * i))[j];
if( Aij )
{
//Uj+= AijT*Aij
cvGEMM( Aij, Aij, 1, U[j], 1, U[j], CV_GEMM_A_T );
//ea_j += AijT * e_ij
CvMat eij;
int index = ((int*)(Vis_index->data.ptr + i * Vis_index->step))[j];
cvGetSubRect( err, &eij, cvRect( 0, index, 1, Aij->height /*width of transposed Aij*/ ) );
cvGEMM( Aij, &eij, 1, ea[j], 1, ea[j], CV_GEMM_A_T );
}
}
} //U_j and ea_j computed for all j
//compute V_i and eb_i
for( int i = 0; i < num_points; i++ )
{
cvSetZero(V[i]);
cvSetZero(eb[i]);
//summ by i (number of points)
for( int j = 0; j < num_cams; j++ )
{
//get Bij
CvMat* Bij = ((CvMat**)(B->data.ptr + B->step * i))[j];
if( Bij )
{
//Vi+= BijT*Bij
cvGEMM( Bij, Bij, 1, V[i], 1, V[i], CV_GEMM_A_T );
//eb_i += BijT * e_ij
int index = ((int*)(Vis_index->data.ptr + i * Vis_index->step))[j];
CvMat eij;
cvGetSubRect( err, &eij, cvRect( 0, index, 1, Bij->height /*width of transposed Bij*/ ) );
cvGEMM( Bij, &eij, 1, eb[i], 1, eb[i], CV_GEMM_A_T );
}
}
} //V_i and eb_i computed for all i
//compute W_ij
for( int i = 0; i < num_points; i++ )
{
for( int j = 0; j < num_cams; j++ )
{
CvMat* Aij = ((CvMat**)(A->data.ptr + A->step * i))[j];
if( Aij ) //visible
{
CvMat* Bij = ((CvMat**)(B->data.ptr + B->step * i))[j];
CvMat* Wij = ((CvMat**)(W->data.ptr + W->step * j))[i];
//multiply
cvGEMM( Aij, Bij, 1, NULL, 0, Wij, CV_GEMM_A_T );
}
}
} //Wij computed
//backup diagonal of JtJ before we start augmenting it
{
CvMat dia;
CvMat subr;
for( int j = 0; j < num_cams; j++ )
{
cvGetDiag(U[j], &dia);
cvGetSubRect(JtJ_diag, &subr,
cvRect(0, j*num_cam_param, 1, num_cam_param ));
cvCopy( &dia, &subr );
}
for( int i = 0; i < num_points; i++ )
{
cvGetDiag(V[i], &dia);
cvGetSubRect(JtJ_diag, &subr,
cvRect(0, num_cams*num_cam_param + i * num_point_param, 1, num_point_param ));
cvCopy( &dia, &subr );
}
}
if( iters == 0 )
{
//initialize lambda. It is set to 1e-3 * average diagonal element in JtJ
double average_diag = 0;
for( int j = 0; j < num_cams; j++ )
{
average_diag += cvTrace( U[j] ).val[0];
}
for( int i = 0; i < num_points; i++ )
{
average_diag += cvTrace( V[i] ).val[0];
}
average_diag /= (num_cams*num_cam_param + num_points * num_point_param );
lambda = 1e-3 * average_diag;
}
//now we are going to find good step and make it
for(;;)
{
//augmentation of diagonal
for(int j = 0; j < num_cams; j++ )
{
CvMat diag;
cvGetDiag( U[j], &diag );
#if 1
cvAddS( &diag, cvScalar( lambda ), &diag );
#else
cvScale( &diag, &diag, 1 + lambda );
#endif
}
for(int i = 0; i < num_points; i++ )
{
CvMat diag;
cvGetDiag( V[i], &diag );
#if 1
cvAddS( &diag, cvScalar( lambda ), &diag );
#else
cvScale( &diag, &diag, 1 + lambda );
#endif
}
bool error = false;
//compute inv(V*)
bool inverted_ok = true;
for(int i = 0; i < num_points; i++ )
{
double det = cvInvert( V[i], inv_V_star[i] );
if( fabs(det) <= FLT_EPSILON )
{
inverted_ok = false;
break;
} //means we did wrong augmentation, try to choose different lambda
}
if( inverted_ok )
{
cvSetZero( E );
//loop through cameras, compute upper diagonal blocks of matrix S
for( int j = 0; j < num_cams; j++ )
{
//compute Yij = Wij (V*_i)^-1 for all i (if Wij exists/nonzero)
for( int i = 0; i < num_points; i++ )
{
//
CvMat* Wij = ((CvMat**)(W->data.ptr + W->step * j))[i];
if( Wij )
{
cvMatMul( Wij, inv_V_star[i], Yj[i] );
}
}
//compute Sjk for k>=j (because Sjk = Skj)
for( int k = j; k < num_cams; k++ )
{
cvSetZero( YWt );
for( int i = 0; i < num_points; i++ )
{
//check that both Wij and Wik exist
CvMat* Wij = ((CvMat**)(W->data.ptr + W->step * j))[i];
CvMat* Wik = ((CvMat**)(W->data.ptr + W->step * k))[i];
if( Wij && Wik )
{
//multiply YWt += Yj[i]*Wik'
cvGEMM( Yj[i], Wik, 1, YWt, 1, YWt, CV_GEMM_B_T /*transpose Wik*/ );
}
}
//copy result to matrix S
CvMat Sjk;
//extract submat
cvGetSubRect( S, &Sjk, cvRect( k * num_cam_param, j * num_cam_param, num_cam_param, num_cam_param ));
//if j==k, add diagonal
if( j != k )
{
//just copy with minus
cvScale( YWt, &Sjk, -1 ); //if we set initial S to zero then we can use cvSub( Sjk, YWt, Sjk);
}
else
{
//add diagonal value
//subtract YWt from augmented Uj
cvSub( U[j], YWt, &Sjk );
}
}
//compute right part of equation involving matrix S
// e_j=ea_j - \sum_i Y_ij eb_i
{
CvMat e_j;
//select submat
cvGetSubRect( E, &e_j, cvRect( 0, j * num_cam_param, 1, num_cam_param ) );
for( int i = 0; i < num_points; i++ )
{
CvMat* Wij = ((CvMat**)(W->data.ptr + W->step * j))[i];
if( Wij )
cvMatMulAdd( Yj[i], eb[i], &e_j, &e_j );
}
cvSub( ea[j], &e_j, &e_j );
}
}
//fill below diagonal elements of matrix S
cvCompleteSymm( S, 0 /*from upper to low*/ ); //operation may be done by nonzero blocks or during upper diagonal computation
//Solve linear system S * deltaP_a = E
CvMat dpa;
cvGetSubRect( deltaP, &dpa, cvRect(0, 0, 1, S->width ) );
int res = cvSolve( S, E, &dpa );
if( res ) //system solved ok
{
//compute db_i
for( int i = 0; i < num_points; i++ )
{
CvMat dbi;
cvGetSubRect( deltaP, &dbi, cvRect( 0, dpa.height + i * num_point_param, 1, num_point_param ) );
/* compute \sum_j W_ij^T da_j */
for( int j = 0; j < num_cams; j++ )
{
//get Wij
CvMat* Wij = ((CvMat**)(W->data.ptr + W->step * j))[i];
if( Wij )
{
//get da_j
CvMat daj;
cvGetSubRect( &dpa, &daj, cvRect( 0, j * num_cam_param, 1, num_cam_param ));
cvGEMM( Wij, &daj, 1, &dbi, 1, &dbi, CV_GEMM_A_T /* transpose Wij */ );
}
}
//finalize dbi
cvSub( eb[i], &dbi, &dbi );
cvMatMul(inv_V_star[i], &dbi, &dbi ); //here we get final dbi
} //now we computed whole deltaP
//add deltaP to delta
cvAdd( prevP, deltaP, P );
//evaluate function with new parameters
ask_for_proj(); // func( P, hX );
//compute error
errNorm = cvNorm( X, hX, CV_L2 );
}
else
{
error = true;
}
}
else
{
error = true;
}
//check solution
if( error || /* singularities somewhere */
errNorm > prevErrNorm ) //step was not accepted
{
//increase lambda and reject change
lambda *= 10;
//restore diagonal from backup
{
CvMat dia;
CvMat subr;
for( int j = 0; j < num_cams; j++ )
{
cvGetDiag(U[j], &dia);
cvGetSubRect(JtJ_diag, &subr,
cvRect(0, j*num_cam_param, 1, num_cam_param ));
cvCopy( &subr, &dia );
}
for( int i = 0; i < num_points; i++ )
{
cvGetDiag(V[i], &dia);
cvGetSubRect(JtJ_diag, &subr,
cvRect(0, num_cams*num_cam_param + i * num_point_param, 1, num_point_param ));
cvCopy( &subr, &dia );
}
}
}
else //all is ok
{
//accept change and decrease lambda
lambda /= 10;
lambda = MAX(lambda, 1e-16);
prevErrNorm = errNorm;
//compute new projection error vector
cvSub( X, hX, err );
break;
}
}
iters++;
double param_change_norm = cvNorm(P, prevP, CV_RELATIVE_L2);
//check termination criteria
if( (criteria.type&CV_TERMCRIT_ITER && iters > criteria.max_iter ) ||
(criteria.type&CV_TERMCRIT_EPS && param_change_norm < criteria.epsilon) )
{
done = true;
break;
}
else
{
//copy new params and continue iterations
cvCopy( P, prevP );
}
}
cvReleaseMat(&YWt);
cvReleaseMat(&E);
}
//Utilities
void fjac(int /*i*/, int /*j*/, CvMat *point_params, CvMat* cam_params, CvMat* A, CvMat* B, void* /*data*/)
{
//compute jacobian per camera parameters (i.e. Aij)
//take i-th point 3D current coordinates
CvMat _Mi;
cvReshape(point_params, &_Mi, 3, 1 );
CvMat* _mp = cvCreateMat(1, 2, CV_64F ); //projection of the point
//split camera params into different matrices
CvMat _ri, _ti, _k;
cvGetRows( cam_params, &_ri, 0, 3 );
cvGetRows( cam_params, &_ti, 3, 6 );
double intr_data[9] = {0, 0, 0, 0, 0, 0, 0, 0, 1};
intr_data[0] = cam_params->data.db[6];
intr_data[4] = cam_params->data.db[7];
intr_data[2] = cam_params->data.db[8];
intr_data[5] = cam_params->data.db[9];
CvMat matA = cvMat(3,3, CV_64F, intr_data );
CvMat _dpdr, _dpdt, _dpdf, _dpdc, _dpdk;
bool have_dk = cam_params->height - 10 ? true : false;
cvGetCols( A, &_dpdr, 0, 3 );
cvGetCols( A, &_dpdt, 3, 6 );
cvGetCols( A, &_dpdf, 6, 8 );
cvGetCols( A, &_dpdc, 8, 10 );
if( have_dk )
{
cvGetRows( cam_params, &_k, 10, cam_params->height );
cvGetCols( A, &_dpdk, 10, A->width );
}
cvProjectPoints2( &_Mi, &_ri, &_ti, &matA, have_dk ? &_k : NULL, _mp, &_dpdr, &_dpdt,
&_dpdf, &_dpdc, have_dk ? &_dpdk : NULL, 0);
cvReleaseMat( &_mp );
//compute jacobian for point params
//compute dMeasure/dPoint3D
// x = (r11 * X + r12 * Y + r13 * Z + t1)
// y = (r21 * X + r22 * Y + r23 * Z + t2)
// z = (r31 * X + r32 * Y + r33 * Z + t3)
// x' = x/z
// y' = y/z
//d(x') = ( dx*z - x*dz)/(z*z)
//d(y') = ( dy*z - y*dz)/(z*z)
//g = 1 + k1*r_2 + k2*r_4 + k3*r_6
//r_2 = x'*x' + y'*y'
//d(r_2) = 2*x'*dx' + 2*y'*dy'
//dg = k1* d(r_2) + k2*2*r_2*d(r_2) + k3*3*r_2*r_2*d(r_2)
//x" = x'*g + 2*p1*x'*y' + p2(r_2+2*x'_2)
//y" = y'*g + p1(r_2+2*y'_2) + 2*p2*x'*y'
//d(x") = d(x') * g + x' * d(g) + 2*p1*( d(x')*y' + x'*dy) + p2*(d(r_2) + 2*2*x'* dx')
//d(y") = d(y') * g + y' * d(g) + 2*p2*( d(x')*y' + x'*dy) + p1*(d(r_2) + 2*2*y'* dy')
// u = fx*( x") + cx
// v = fy*( y") + cy
// du = fx * d(x") = fx * ( dx*z - x*dz)/ (z*z)
// dv = fy * d(y") = fy * ( dy*z - y*dz)/ (z*z)
// dx/dX = r11, dx/dY = r12, dx/dZ = r13
// dy/dX = r21, dy/dY = r22, dy/dZ = r23
// dz/dX = r31, dz/dY = r32, dz/dZ = r33
// du/dX = fx*(r11*z-x*r31)/(z*z)
// du/dY = fx*(r12*z-x*r32)/(z*z)
// du/dZ = fx*(r13*z-x*r33)/(z*z)
// dv/dX = fy*(r21*z-y*r31)/(z*z)
// dv/dY = fy*(r22*z-y*r32)/(z*z)
// dv/dZ = fy*(r23*z-y*r33)/(z*z)
//get rotation matrix
double R[9], t[3], fx = intr_data[0], fy = intr_data[4];
CvMat matR = cvMat( 3, 3, CV_64F, R );
cvRodrigues2(&_ri, &matR);
double X,Y,Z;
X = point_params->data.db[0];
Y = point_params->data.db[1];
Z = point_params->data.db[2];
t[0] = _ti.data.db[0];
t[1] = _ti.data.db[1];
t[2] = _ti.data.db[2];
//compute x,y,z
double x = R[0] * X + R[1] * Y + R[2] * Z + t[0];
double y = R[3] * X + R[4] * Y + R[5] * Z + t[1];
double z = R[6] * X + R[7] * Y + R[8] * Z + t[2];
#if 1
//compute x',y'
double x_strike = x/z;
double y_strike = y/z;
//compute dx',dy' matrix
//
// dx'/dX dx'/dY dx'/dZ =
// dy'/dX dy'/dY dy'/dZ
double coeff[6] = { z, 0, -x,
0, z, -y };
CvMat coeffmat = cvMat( 2, 3, CV_64F, coeff );
CvMat* dstrike_dbig = cvCreateMat(2,3,CV_64F);
cvMatMul(&coeffmat, &matR, dstrike_dbig);
cvScale(dstrike_dbig, dstrike_dbig, 1/(z*z) );
if( have_dk )
{
double strike_[2] = {x_strike, y_strike};
CvMat strike = cvMat(1, 2, CV_64F, strike_);
//compute r_2
double r_2 = x_strike*x_strike + y_strike*y_strike;
double r_4 = r_2*r_2;
double r_6 = r_4*r_2;
//compute d(r_2)/dbig
CvMat* dr2_dbig = cvCreateMat(1,3,CV_64F);
cvMatMul( &strike, dstrike_dbig, dr2_dbig);
cvScale( dr2_dbig, dr2_dbig, 2 );
double& k1 = _k.data.db[0];
double& k2 = _k.data.db[1];
double& p1 = _k.data.db[2];
double& p2 = _k.data.db[3];
double k3 = 0;
if( _k.cols*_k.rows == 5 )
{
k3 = _k.data.db[4];
}
//compute dg/dbig
double dg_dr2 = k1 + k2*2*r_2 + k3*3*r_4;
double g = 1+k1*r_2+k2*r_4+k3*r_6;
CvMat* dg_dbig = cvCreateMat(1,3,CV_64F);
cvScale( dr2_dbig, dg_dbig, dg_dr2 );
CvMat* tmp = cvCreateMat( 2, 3, CV_64F );
CvMat* dstrike2_dbig = cvCreateMat( 2, 3, CV_64F );
double c[4] = { g+2*p1*y_strike+4*p2*x_strike, 2*p1*x_strike,
2*p2*y_strike, g+2*p2*x_strike + 4*p1*y_strike };
CvMat coeffmat = cvMat(2,2,CV_64F, c );
cvMatMul(&coeffmat, dstrike_dbig, dstrike2_dbig );
cvGEMM( &strike, dg_dbig, 1, NULL, 0, tmp, CV_GEMM_A_T );
cvAdd( dstrike2_dbig, tmp, dstrike2_dbig );
double p[2] = { p2, p1 };
CvMat pmat = cvMat(2, 1, CV_64F, p );
cvMatMul( &pmat, dr2_dbig ,tmp);
cvAdd( dstrike2_dbig, tmp, dstrike2_dbig );
cvCopy( dstrike2_dbig, B );
cvReleaseMat(&dr2_dbig);
cvReleaseMat(&dg_dbig);
cvReleaseMat(&tmp);
cvReleaseMat(&dstrike2_dbig);
cvReleaseMat(&tmp);
}
else
{
cvCopy(dstrike_dbig, B);
}
//multiply by fx, fy
CvMat row;
cvGetRows( B, &row, 0, 1 );
cvScale( &row, &row, fx );
cvGetRows( B, &row, 1, 2 );
cvScale( &row, &row, fy );
#else
double k = fx/(z*z);
cvmSet( B, 0, 0, k*(R[0]*z-x*R[6]));
cvmSet( B, 0, 1, k*(R[1]*z-x*R[7]));
cvmSet( B, 0, 2, k*(R[2]*z-x*R[8]));
k = fy/(z*z);
cvmSet( B, 1, 0, k*(R[3]*z-y*R[6]));
cvmSet( B, 1, 1, k*(R[4]*z-y*R[7]));
cvmSet( B, 1, 2, k*(R[5]*z-y*R[8]));
#endif
};
void func(int /*i*/, int /*j*/, CvMat *point_params, CvMat* cam_params, CvMat* estim, void* /*data*/)
{
//just do projections
CvMat _Mi;
cvReshape( point_params, &_Mi, 3, 1 );
CvMat* _mp = cvCreateMat(1, 2, CV_64F ); //projection of the point
//split camera params into different matrices
CvMat _ri, _ti, _k;
cvGetRows( cam_params, &_ri, 0, 3 );
cvGetRows( cam_params, &_ti, 3, 6 );
double intr_data[9] = {0, 0, 0, 0, 0, 0, 0, 0, 1};
intr_data[0] = cam_params->data.db[6];
intr_data[4] = cam_params->data.db[7];
intr_data[2] = cam_params->data.db[8];
intr_data[5] = cam_params->data.db[9];
CvMat matA = cvMat(3,3, CV_64F, intr_data );
//int cn = CV_MAT_CN(_Mi.type);
bool have_dk = cam_params->height - 10 ? true : false;
if( have_dk )
{
cvGetRows( cam_params, &_k, 10, cam_params->height );
}
cvProjectPoints2( &_Mi, &_ri, &_ti, &matA, have_dk ? &_k : NULL, _mp, NULL, NULL,
NULL, NULL, NULL, 0);
cvTranspose( _mp, estim );
cvReleaseMat( &_mp );
};
void fjac_new(int i, int j, Mat& point_params, Mat& cam_params, Mat& A, Mat& B, void* data)
{
CvMat _point_params = point_params, _cam_params = cam_params, matA = A, matB = B;
fjac(i,j, &_point_params, &_cam_params, &matA, &matB, data);
};
void func_new(int i, int j, Mat& point_params, Mat& cam_params, Mat& estim, void* data)
{
CvMat _point_params = point_params, _cam_params = cam_params, _estim = estim;
func(i,j,&_point_params,&_cam_params,&_estim,data);
};
void LevMarqSparse::bundleAdjust( vector<Point3d>& points, //positions of points in global coordinate system (input and output)
const vector<vector<Point2d> >& imagePoints, //projections of 3d points for every camera
const vector<vector<int> >& visibility, //visibility of 3d points for every camera
vector<Mat>& cameraMatrix, //intrinsic matrices of all cameras (input and output)
vector<Mat>& R, //rotation matrices of all cameras (input and output)
vector<Mat>& T, //translation vector of all cameras (input and output)
vector<Mat>& distCoeffs, //distortion coefficients of all cameras (input and output)
const TermCriteria& criteria)
//,enum{MOTION_AND_STRUCTURE,MOTION,STRUCTURE})
{
int num_points = (int)points.size();
int num_cameras = (int)cameraMatrix.size();
CV_Assert( imagePoints.size() == (size_t)num_cameras &&
visibility.size() == (size_t)num_cameras &&
R.size() == (size_t)num_cameras &&
T.size() == (size_t)num_cameras &&
(distCoeffs.size() == (size_t)num_cameras || distCoeffs.size() == 0) );
int numdist = distCoeffs.size() ? (distCoeffs[0].rows * distCoeffs[0].cols) : 0;
int num_cam_param = 3 /* rotation vector */ + 3 /* translation vector */
+ 2 /* fx, fy */ + 2 /* cx, cy */ + numdist;
int num_point_param = 3;
//collect camera parameters into vector
Mat params( num_cameras * num_cam_param + num_points * num_point_param, 1, CV_64F );
//fill camera params
for( int i = 0; i < num_cameras; i++ )
{
//rotation
Mat rot_vec; Rodrigues( R[i], rot_vec );
Mat dst = params.rowRange(i*num_cam_param, i*num_cam_param+3);
rot_vec.copyTo(dst);
//translation
dst = params.rowRange(i*num_cam_param + 3, i*num_cam_param+6);
T[i].copyTo(dst);
//intrinsic camera matrix
double* intr_data = (double*)cameraMatrix[i].data;
double* intr = (double*)(params.data + params.step * (i*num_cam_param+6));
//focals
intr[0] = intr_data[0]; //fx
intr[1] = intr_data[4]; //fy
//center of projection
intr[2] = intr_data[2]; //cx
intr[3] = intr_data[5]; //cy
//add distortion if exists
if( distCoeffs.size() )
{
dst = params.rowRange(i*num_cam_param + 10, i*num_cam_param+10+numdist);
distCoeffs[i].copyTo(dst);
}
}
//fill point params
Mat ptparams(num_points, 1, CV_64FC3, params.data + num_cameras*num_cam_param*params.step);
Mat _points(points);
CV_Assert(_points.size() == ptparams.size() && _points.type() == ptparams.type());
_points.copyTo(ptparams);
//convert visibility vectors to visibility matrix
Mat vismat(num_points, num_cameras, CV_32S);
for( int i = 0; i < num_cameras; i++ )
{
//get row
Mat col = vismat.col(i);
Mat((int)visibility[i].size(), 1, vismat.type(), (void*)&visibility[i][0]).copyTo( col );
}
int num_proj = countNonZero(vismat); //total number of points projections
//collect measurements
Mat X(num_proj*2,1,CV_64F); //measurement vector
int counter = 0;
for(int i = 0; i < num_points; i++ )
{
for(int j = 0; j < num_cameras; j++ )
{
//check visibility
if( visibility[j][i] )
{
//extract point and put tu vector
Point2d p = imagePoints[j][i];
((double*)(X.data))[counter] = p.x;
((double*)(X.data))[counter+1] = p.y;
counter+=2;
}
}
}
LevMarqSparse levmar( num_points, num_cameras, num_point_param, num_cam_param, 2, vismat, params, X,
TermCriteria(criteria), fjac_new, func_new, NULL );
//extract results
//fill point params
Mat final_points(num_points, 1, CV_64FC3,
levmar.P->data.db + num_cameras*num_cam_param *levmar.P->step);
CV_Assert(_points.size() == final_points.size() && _points.type() == final_points.type());
final_points.copyTo(_points);
//fill camera params
for( int i = 0; i < num_cameras; i++ )
{
//rotation
Mat rot_vec = Mat(levmar.P).rowRange(i*num_cam_param, i*num_cam_param+3);
Rodrigues( rot_vec, R[i] );
//translation
T[i] = Mat(levmar.P).rowRange(i*num_cam_param + 3, i*num_cam_param+6);
//intrinsic camera matrix
double* intr_data = (double*)cameraMatrix[i].data;
double* intr = (double*)(Mat(levmar.P).data + Mat(levmar.P).step * (i*num_cam_param+6));
//focals
intr_data[0] = intr[0]; //fx
intr_data[4] = intr[1]; //fy
//center of projection
intr_data[2] = intr[2]; //cx
intr_data[5] = intr[3]; //cy
//add distortion if exists
if( distCoeffs.size() )
{
params.rowRange(i*num_cam_param + 10, i*num_cam_param+10+numdist).copyTo(distCoeffs[i]);
}
}
}
}// end of namespace cv