gtsam/gtsam/geometry/Cal3DS2_Base.cpp

209 lines
7.0 KiB
C++

/* ----------------------------------------------------------------------------
* GTSAM Copyright 2010, Georgia Tech Research Corporation,
* Atlanta, Georgia 30332-0415
* All Rights Reserved
* Authors: Frank Dellaert, et al. (see THANKS for the full author list)
* See LICENSE for the license information
* -------------------------------------------------------------------------- */
/**
* @file Cal3DS2_Base.cpp
* @date Feb 28, 2010
* @author ydjian
*/
#include <gtsam/base/Vector.h>
#include <gtsam/base/Matrix.h>
#include <gtsam/geometry/Point2.h>
#include <gtsam/geometry/Point3.h>
#include <gtsam/geometry/Cal3DS2_Base.h>
namespace gtsam {
/* ************************************************************************* */
Cal3DS2_Base::Cal3DS2_Base(const Vector &v):
fx_(v[0]), fy_(v[1]), s_(v[2]), u0_(v[3]), v0_(v[4]), k1_(v[5]), k2_(v[6]), p1_(v[7]), p2_(v[8]){}
/* ************************************************************************* */
Matrix Cal3DS2_Base::K() const {
return (Matrix(3, 3) << fx_, s_, u0_, 0.0, fy_, v0_, 0.0, 0.0, 1.0);
}
/* ************************************************************************* */
Vector Cal3DS2_Base::vector() const {
return (Vector(9) << fx_, fy_, s_, u0_, v0_, k1_, k2_, p1_, p2_);
}
/* ************************************************************************* */
void Cal3DS2_Base::print(const std::string& s_) const {
gtsam::print(K(), s_ + ".K");
gtsam::print(Vector(k()), s_ + ".k");
}
/* ************************************************************************* */
bool Cal3DS2_Base::equals(const Cal3DS2_Base& K, double tol) const {
if (fabs(fx_ - K.fx_) > tol || fabs(fy_ - K.fy_) > tol || fabs(s_ - K.s_) > tol ||
fabs(u0_ - K.u0_) > tol || fabs(v0_ - K.v0_) > tol || fabs(k1_ - K.k1_) > tol ||
fabs(k2_ - K.k2_) > tol || fabs(p1_ - K.p1_) > tol || fabs(p2_ - K.p2_) > tol)
return false;
return true;
}
/* ************************************************************************* */
static Matrix29 D2dcalibration(double x, double y, double xx,
double yy, double xy, double rr, double r4, double pnx, double pny,
const Matrix2& DK) {
Matrix25 DR1;
DR1 << pnx, 0.0, pny, 1.0, 0.0, 0.0, pny, 0.0, 0.0, 1.0;
Matrix24 DR2;
DR2 << x * rr, x * r4, 2 * xy, rr + 2 * xx, //
y * rr, y * r4, rr + 2 * yy, 2 * xy;
Matrix29 D;
D << DR1, DK * DR2;
return D;
}
/* ************************************************************************* */
static Matrix2 D2dintrinsic(double x, double y, double rr,
double g, double k1, double k2, double p1, double p2,
const Matrix2& DK) {
const double drdx = 2. * x;
const double drdy = 2. * y;
const double dgdx = k1 * drdx + k2 * 2. * rr * drdx;
const double dgdy = k1 * drdy + k2 * 2. * rr * drdy;
// Dx = 2*p1*xy + p2*(rr+2*xx);
// Dy = 2*p2*xy + p1*(rr+2*yy);
const double dDxdx = 2. * p1 * y + p2 * (drdx + 4. * x);
const double dDxdy = 2. * p1 * x + p2 * drdy;
const double dDydx = 2. * p2 * y + p1 * drdx;
const double dDydy = 2. * p2 * x + p1 * (drdy + 4. * y);
Matrix2 DR;
DR << g + x * dgdx + dDxdx, x * dgdy + dDxdy, //
y * dgdx + dDydx, g + y * dgdy + dDydy;
return DK * DR;
}
/* ************************************************************************* */
Point2 Cal3DS2_Base::uncalibrate(const Point2& p,
boost::optional<Matrix29&> H1,
boost::optional<Matrix2&> H2) const {
// rr = x^2 + y^2;
// g = (1 + k(1)*rr + k(2)*rr^2);
// dp = [2*k(3)*x*y + k(4)*(rr + 2*x^2); 2*k(4)*x*y + k(3)*(rr + 2*y^2)];
// pi(:,i) = g * pn(:,i) + dp;
const double x = p.x(), y = p.y(), xy = x * y, xx = x * x, yy = y * y;
const double rr = xx + yy;
const double r4 = rr * rr;
const double g = 1. + k1_ * rr + k2_ * r4; // scaling factor
// tangential component
const double dx = 2. * p1_ * xy + p2_ * (rr + 2. * xx);
const double dy = 2. * p2_ * xy + p1_ * (rr + 2. * yy);
// Radial and tangential distortion applied
const double pnx = g * x + dx;
const double pny = g * y + dy;
Matrix2 DK;
if (H1 || H2) DK << fx_, s_, 0.0, fy_;
// Derivative for calibration
if (H1)
*H1 = D2dcalibration(x, y, xx, yy, xy, rr, r4, pnx, pny, DK);
// Derivative for points
if (H2)
*H2 = D2dintrinsic(x, y, rr, g, k1_, k2_, p1_, p2_, DK);
// Regular uncalibrate after distortion
return Point2(fx_ * pnx + s_ * pny + u0_, fy_ * pny + v0_);
}
/* ************************************************************************* */
Point2 Cal3DS2_Base::uncalibrate(const Point2& p,
boost::optional<Matrix&> H1,
boost::optional<Matrix&> H2) const {
if (H1 || H2) {
Matrix29 D1;
Matrix2 D2;
Point2 pu = uncalibrate(p, D1, D2);
if (H1)
*H1 = D1;
if (H2)
*H2 = D2;
return pu;
} else {
return uncalibrate(p);
}
}
/* ************************************************************************* */
Point2 Cal3DS2_Base::calibrate(const Point2& pi, const double tol) const {
// Use the following fixed point iteration to invert the radial distortion.
// pn_{t+1} = (inv(K)*pi - dp(pn_{t})) / g(pn_{t})
const Point2 invKPi ((1 / fx_) * (pi.x() - u0_ - (s_ / fy_) * (pi.y() - v0_)),
(1 / fy_) * (pi.y() - v0_));
// initialize by ignoring the distortion at all, might be problematic for pixels around boundary
Point2 pn = invKPi;
// iterate until the uncalibrate is close to the actual pixel coordinate
const int maxIterations = 10;
int iteration;
for (iteration = 0; iteration < maxIterations; ++iteration) {
if (uncalibrate(pn).distance(pi) <= tol) break;
const double x = pn.x(), y = pn.y(), xy = x * y, xx = x * x, yy = y * y;
const double rr = xx + yy;
const double g = (1 + k1_ * rr + k2_ * rr * rr);
const double dx = 2 * p1_ * xy + p2_ * (rr + 2 * xx);
const double dy = 2 * p2_ * xy + p1_ * (rr + 2 * yy);
pn = (invKPi - Point2(dx, dy)) / g;
}
if ( iteration >= maxIterations )
throw std::runtime_error("Cal3DS2::calibrate fails to converge. need a better initialization");
return pn;
}
/* ************************************************************************* */
Matrix Cal3DS2_Base::D2d_intrinsic(const Point2& p) const {
const double x = p.x(), y = p.y(), xx = x * x, yy = y * y;
const double rr = xx + yy;
const double r4 = rr * rr;
const double g = (1 + k1_ * rr + k2_ * r4);
Matrix2 DK;
DK << fx_, s_, 0.0, fy_;
return D2dintrinsic(x, y, rr, g, k1_, k2_, p1_, p2_, DK);
}
/* ************************************************************************* */
Matrix Cal3DS2_Base::D2d_calibration(const Point2& p) const {
const double x = p.x(), y = p.y(), xx = x * x, yy = y * y, xy = x * y;
const double rr = xx + yy;
const double r4 = rr * rr;
const double g = (1 + k1_ * rr + k2_ * r4);
const double dx = 2 * p1_ * xy + p2_ * (rr + 2 * xx);
const double dy = 2 * p2_ * xy + p1_ * (rr + 2 * yy);
const double pnx = g * x + dx;
const double pny = g * y + dy;
Matrix2 DK;
DK << fx_, s_, 0.0, fy_;
return D2dcalibration(x, y, xx, yy, xy, rr, r4, pnx, pny, DK);
}
}
/* ************************************************************************* */