static public void Test()
        {
            // generate x_i, y_i observations on test function

            var random = new Random();

            int n = 200;

            var X = new Matrix(n, 1);
            var Y = new Matrix(n, 1);

            {
                double a = 100; double b = 102;
                for (int i = 0; i < n; i++)
                {
                    double x = random.NextDouble() / (Math.PI / 4.0) - Math.PI / 8.0;
                    double y = a * Math.Cos(b * x) + b * Math.Sin(a * x) + random.NextDouble() * 0.1;
                    X[i] = x;
                    Y[i] = y;
                }
            }


            Function f = delegate(Matrix parameters)
            {
                // return y_i - f(x_i, parameters) as column vector
                var error = new Matrix(n, 1);

                double a = parameters[0];
                double b = parameters[1];

                for (int i = 0; i < n; i++)
                {
                    double y = a * Math.Cos(b * X[i]) + b * Math.Sin(a * X[i]);
                    error[i] = Y[i] - y;
                }

                return(error);
            };


            var levenbergMarquardt = new LevenbergMarquardt(f);

            var parameters0 = new Matrix(2, 1);

            parameters0[0] = 90;
            parameters0[1] = 96;

            var rmsError = levenbergMarquardt.Minimize(parameters0);
        }
        static double CalibrateColorCamera(List<Matrix> worldPoints, List<System.Drawing.PointF> imagePoints, Matrix cameraMatrix, Matrix distCoeffs, Matrix rotation, Matrix translation)
        {
            int nPoints = worldPoints.Count;

            {
                Matrix R, t;
                CameraMath.DLT(cameraMatrix, distCoeffs, worldPoints, imagePoints, out R, out t);
                var r = CameraMath.RotationVectorFromRotationMatrix(R);
                rotation.Copy(r);
                translation.Copy(t);
            }

            // pack parameters into vector
            // parameters: fx, fy, cx, cy, k1, k2, + 3 for rotation, 3 translation = 12
            int nParameters = 12;
            var parameters = new Matrix(nParameters, 1);

            {
                int pi = 0;
                parameters[pi++] = cameraMatrix[0, 0]; // fx
                parameters[pi++] = cameraMatrix[1, 1]; // fy
                parameters[pi++] = cameraMatrix[0, 2]; // cx
                parameters[pi++] = cameraMatrix[1, 2]; // cy
                parameters[pi++] = distCoeffs[0]; // k1
                parameters[pi++] = distCoeffs[1]; // k2
                parameters[pi++] = rotation[0];
                parameters[pi++] = rotation[1];
                parameters[pi++] = rotation[2];
                parameters[pi++] = translation[0];
                parameters[pi++] = translation[1];
                parameters[pi++] = translation[2];

            }

            // size of our error vector
            int nValues = nPoints * 2; // each component (x,y) is a separate entry

            LevenbergMarquardt.Function function = delegate(Matrix p)
            {
                var fvec = new Matrix(nValues, 1);


                // unpack parameters
                int pi = 0;
                double fx = p[pi++];
                double fy = p[pi++];
                double cx = p[pi++];
                double cy = p[pi++];

                double k1 = p[pi++];
                double k2 = p[pi++];

                var K = Matrix.Identity(3, 3);
                K[0, 0] = fx;
                K[1, 1] = fy;
                K[0, 2] = cx;
                K[1, 2] = cy;

                var d = Matrix.Zero(5, 1);
                d[0] = k1;
                d[1] = k2;

                var r = new Matrix(3, 1);
                r[0] = p[pi++];
                r[1] = p[pi++];
                r[2] = p[pi++];

                var t = new Matrix(3, 1);
                t[0] = p[pi++];
                t[1] = p[pi++];
                t[2] = p[pi++];

                var R = CameraMath.RotationMatrixFromRotationVector(r);



                var x = new Matrix(3, 1);

                int fveci = 0;
                for (int i = 0; i < worldPoints.Count; i++)
                {
                    // transform world point to local camera coordinates
                    x.Mult(R, worldPoints[i]);
                    x.Add(t);

                    // fvec_i = y_i - f(x_i)
                    double u, v;
                    CameraMath.Project(K, d, x[0], x[1], x[2], out u, out v);

                    var imagePoint = imagePoints[i];
                    fvec[fveci++] = imagePoint.X - u;
                    fvec[fveci++] = imagePoint.Y - v;
                }
                return fvec;
            };

            // optimize
            var calibrate = new LevenbergMarquardt(function);
            while (calibrate.State == LevenbergMarquardt.States.Running)
            {
                var rmsError = calibrate.MinimizeOneStep(parameters);
                Console.WriteLine("rms error = " + rmsError);
            }
            for (int i = 0; i < nParameters; i++)
                Console.WriteLine(parameters[i] + "\t");
            Console.WriteLine();

            // unpack parameters
            {
                int pi = 0;
                double fx = parameters[pi++];
                double fy = parameters[pi++];
                double cx = parameters[pi++];
                double cy = parameters[pi++];
                double k1 = parameters[pi++];
                double k2 = parameters[pi++];
                cameraMatrix[0, 0] = fx;
                cameraMatrix[1, 1] = fy;
                cameraMatrix[0, 2] = cx;
                cameraMatrix[1, 2] = cy;
                distCoeffs[0] = k1;
                distCoeffs[1] = k2;
                rotation[0] = parameters[pi++];
                rotation[1] = parameters[pi++];
                rotation[2] = parameters[pi++];
                translation[0] = parameters[pi++];
                translation[1] = parameters[pi++];
                translation[2] = parameters[pi++];
            }


            return calibrate.RMSError;
        }
        static double CalibrateDepthCamera(List<Matrix> worldPoints, List<System.Drawing.PointF> imagePoints, Matrix cameraMatrix, Matrix distCoeffs)
        {
            int nPoints = worldPoints.Count;

            // pack parameters into vector
            // parameters: fx, fy, cx, cy, k1, k2 = 6 parameters
            int nParameters = 6;
            var parameters = new Matrix(nParameters, 1);

            {
                int pi = 0;
                parameters[pi++] = cameraMatrix[0, 0]; // fx
                parameters[pi++] = cameraMatrix[1, 1]; // fy
                parameters[pi++] = cameraMatrix[0, 2]; // cx
                parameters[pi++] = cameraMatrix[1, 2]; // cy
                parameters[pi++] = distCoeffs[0]; // k1
                parameters[pi++] = distCoeffs[1]; // k2
            }

            // size of our error vector
            int nValues = nPoints * 2; // each component (x,y) is a separate entry

            LevenbergMarquardt.Function function = delegate(Matrix p)
            {
                var fvec = new Matrix(nValues, 1);

                // unpack parameters
                int pi = 0;
                double fx = p[pi++];
                double fy = p[pi++];
                double cx = p[pi++];
                double cy = p[pi++];
                double k1 = p[pi++];
                double k2 = p[pi++];

                var K = Matrix.Identity(3, 3);
                K[0, 0] = fx;
                K[1, 1] = fy;
                K[0, 2] = cx;
                K[1, 2] = cy;

                var d = Matrix.Zero(5, 1);
                d[0] = k1;
                d[1] = k2;

                int fveci = 0;
                for (int i = 0; i < worldPoints.Count; i++)
                {
                    // fvec_i = y_i - f(x_i)
                    double u, v;
                    var x = worldPoints[i];
                    CameraMath.Project(K, d, x[0], x[1], x[2], out u, out v);

                    var imagePoint = imagePoints[i];
                    fvec[fveci++] = imagePoint.X - u;
                    fvec[fveci++] = imagePoint.Y - v;
                }
                return fvec;
            };

            // optimize
            var calibrate = new LevenbergMarquardt(function);
            while (calibrate.State == LevenbergMarquardt.States.Running)
            {
                var rmsError = calibrate.MinimizeOneStep(parameters);
                Console.WriteLine("rms error = " + rmsError);
            }
            for (int i = 0; i < nParameters; i++)
                Console.WriteLine(parameters[i] + "\t");
            Console.WriteLine();

            // unpack parameters
            {
                int pi = 0;
                double fx = parameters[pi++];
                double fy = parameters[pi++];
                double cx = parameters[pi++];
                double cy = parameters[pi++];
                double k1 = parameters[pi++];
                double k2 = parameters[pi++];
                cameraMatrix[0, 0] = fx;
                cameraMatrix[1, 1] = fy;
                cameraMatrix[0, 2] = cx;
                cameraMatrix[1, 2] = cy;
                distCoeffs[0] = k1;
                distCoeffs[1] = k2;
            }


            return calibrate.RMSError;
        }
        static double CalibrateColorCamera(List <Matrix> worldPoints, List <System.Drawing.PointF> imagePoints, Matrix cameraMatrix, Matrix distCoeffs, Matrix rotation, Matrix translation)
        {
            int nPoints = worldPoints.Count;

            {
                Matrix R, t;
                CameraMath.DLT(cameraMatrix, distCoeffs, worldPoints, imagePoints, out R, out t);
                //var r = Orientation.RotationVector(R);
                var r = RoomAliveToolkit.ProjectorCameraEnsemble.RotationVectorFromRotationMatrix(R);
                rotation.Copy(r);
                translation.Copy(t);
            }

            // pack parameters into vector
            // parameters: fx, fy, cx, cy, k1, k2, + 3 for rotation, 3 translation = 12
            int nParameters = 12;
            var parameters  = new Matrix(nParameters, 1);

            {
                int pi = 0;
                parameters[pi++] = cameraMatrix[0, 0]; // fx
                parameters[pi++] = cameraMatrix[1, 1]; // fy
                parameters[pi++] = cameraMatrix[0, 2]; // cx
                parameters[pi++] = cameraMatrix[1, 2]; // cy
                parameters[pi++] = distCoeffs[0];      // k1
                parameters[pi++] = distCoeffs[1];      // k2
                parameters[pi++] = rotation[0];
                parameters[pi++] = rotation[1];
                parameters[pi++] = rotation[2];
                parameters[pi++] = translation[0];
                parameters[pi++] = translation[1];
                parameters[pi++] = translation[2];
            }

            // size of our error vector
            int nValues = nPoints * 2; // each component (x,y) is a separate entry

            LevenbergMarquardt.Function function = delegate(Matrix p)
            {
                var fvec = new Matrix(nValues, 1);


                // unpack parameters
                int    pi = 0;
                double fx = p[pi++];
                double fy = p[pi++];
                double cx = p[pi++];
                double cy = p[pi++];

                double k1 = p[pi++];
                double k2 = p[pi++];

                var K = Matrix.Identity(3, 3);
                K[0, 0] = fx;
                K[1, 1] = fy;
                K[0, 2] = cx;
                K[1, 2] = cy;

                var d = Matrix.Zero(5, 1);
                d[0] = k1;
                d[1] = k2;

                var r = new Matrix(3, 1);
                r[0] = p[pi++];
                r[1] = p[pi++];
                r[2] = p[pi++];

                var t = new Matrix(3, 1);
                t[0] = p[pi++];
                t[1] = p[pi++];
                t[2] = p[pi++];

                //var R = Orientation.Rodrigues(r);
                var R = RoomAliveToolkit.ProjectorCameraEnsemble.RotationMatrixFromRotationVector(r);



                var x = new Matrix(3, 1);

                int fveci = 0;
                for (int i = 0; i < worldPoints.Count; i++)
                {
                    // transform world point to local camera coordinates
                    x.Mult(R, worldPoints[i]);
                    x.Add(t);

                    // fvec_i = y_i - f(x_i)
                    double u, v;
                    CameraMath.Project(K, d, x[0], x[1], x[2], out u, out v);

                    var imagePoint = imagePoints[i];
                    fvec[fveci++] = imagePoint.X - u;
                    fvec[fveci++] = imagePoint.Y - v;
                }
                return(fvec);
            };

            // optimize
            var calibrate = new LevenbergMarquardt(function);

            while (calibrate.State == LevenbergMarquardt.States.Running)
            {
                var rmsError = calibrate.MinimizeOneStep(parameters);
                Console.WriteLine("rms error = " + rmsError);
            }
            for (int i = 0; i < nParameters; i++)
            {
                Console.WriteLine(parameters[i] + "\t");
            }
            Console.WriteLine();

            // unpack parameters
            {
                int    pi = 0;
                double fx = parameters[pi++];
                double fy = parameters[pi++];
                double cx = parameters[pi++];
                double cy = parameters[pi++];
                double k1 = parameters[pi++];
                double k2 = parameters[pi++];
                cameraMatrix[0, 0] = fx;
                cameraMatrix[1, 1] = fy;
                cameraMatrix[0, 2] = cx;
                cameraMatrix[1, 2] = cy;
                distCoeffs[0]      = k1;
                distCoeffs[1]      = k2;
                rotation[0]        = parameters[pi++];
                rotation[1]        = parameters[pi++];
                rotation[2]        = parameters[pi++];
                translation[0]     = parameters[pi++];
                translation[1]     = parameters[pi++];
                translation[2]     = parameters[pi++];
            }


            return(calibrate.RMSError);
        }
        static double CalibrateDepthCamera(List <Matrix> worldPoints, List <System.Drawing.PointF> imagePoints, Matrix cameraMatrix, Matrix distCoeffs)
        {
            int nPoints = worldPoints.Count;

            // pack parameters into vector
            // parameters: fx, fy, cx, cy, k1, k2 = 6 parameters
            int nParameters = 6;
            var parameters  = new Matrix(nParameters, 1);

            {
                int pi = 0;
                parameters[pi++] = cameraMatrix[0, 0]; // fx
                parameters[pi++] = cameraMatrix[1, 1]; // fy
                parameters[pi++] = cameraMatrix[0, 2]; // cx
                parameters[pi++] = cameraMatrix[1, 2]; // cy
                parameters[pi++] = distCoeffs[0];      // k1
                parameters[pi++] = distCoeffs[1];      // k2
            }

            // size of our error vector
            int nValues = nPoints * 2; // each component (x,y) is a separate entry

            LevenbergMarquardt.Function function = delegate(Matrix p)
            {
                var fvec = new Matrix(nValues, 1);

                // unpack parameters
                int    pi = 0;
                double fx = p[pi++];
                double fy = p[pi++];
                double cx = p[pi++];
                double cy = p[pi++];
                double k1 = p[pi++];
                double k2 = p[pi++];

                var K = Matrix.Identity(3, 3);
                K[0, 0] = fx;
                K[1, 1] = fy;
                K[0, 2] = cx;
                K[1, 2] = cy;

                var d = Matrix.Zero(5, 1);
                d[0] = k1;
                d[1] = k2;

                int fveci = 0;
                for (int i = 0; i < worldPoints.Count; i++)
                {
                    // fvec_i = y_i - f(x_i)
                    double u, v;
                    var    x = worldPoints[i];
                    CameraMath.Project(K, d, x[0], x[1], x[2], out u, out v);

                    var imagePoint = imagePoints[i];
                    fvec[fveci++] = imagePoint.X - u;
                    fvec[fveci++] = imagePoint.Y - v;
                }
                return(fvec);
            };

            // optimize
            var calibrate = new LevenbergMarquardt(function);

            while (calibrate.State == LevenbergMarquardt.States.Running)
            {
                var rmsError = calibrate.MinimizeOneStep(parameters);
                Console.WriteLine("rms error = " + rmsError);
            }
            for (int i = 0; i < nParameters; i++)
            {
                Console.WriteLine(parameters[i] + "\t");
            }
            Console.WriteLine();

            // unpack parameters
            {
                int    pi = 0;
                double fx = parameters[pi++];
                double fy = parameters[pi++];
                double cx = parameters[pi++];
                double cy = parameters[pi++];
                double k1 = parameters[pi++];
                double k2 = parameters[pi++];
                cameraMatrix[0, 0] = fx;
                cameraMatrix[1, 1] = fy;
                cameraMatrix[0, 2] = cx;
                cameraMatrix[1, 2] = cy;
                distCoeffs[0]      = k1;
                distCoeffs[1]      = k2;
            }


            return(calibrate.RMSError);
        }
        static public void Test()
        {
            // generate x_i, y_i observations on test function

            var random = new Random();

            int n = 200;

            var X = new Matrix(n, 1);
            var Y = new Matrix(n, 1);

            {
                double a = 100; double b = 102;
                for (int i = 0; i < n; i++)
                {
                    double x = random.NextDouble() / (Math.PI / 4.0) - Math.PI / 8.0;
                    double y = a * Math.Cos(b * x) + b * Math.Sin(a * x) + random.NextDouble()*0.1;
                    X[i] = x;
                    Y[i] = y;
                }
            }


            Function f = delegate(Matrix parameters)
            {
                // return y_i - f(x_i, parameters) as column vector
                var error = new Matrix(n, 1);

                double a = parameters[0];
                double b = parameters[1];

                for (int i = 0; i < n; i++)
                {
                    double y = a * Math.Cos(b * X[i]) + b * Math.Sin(a * X[i]);
                    error[i] = Y[i] - y;
                }

                return error;
            };


            var levenbergMarquardt = new LevenbergMarquardt(f);

            var parameters0 = new Matrix(2, 1);
            parameters0[0] = 90;
            parameters0[1] = 96;

            var rmsError = levenbergMarquardt.Minimize(parameters0);


        }
        public static double CalibrateCameraExtrinsicsOnly(List<List<Matrix>> worldPointSets, List<List<System.Drawing.PointF>> imagePointSets,
    Matrix cameraMatrix, ref List<Matrix> rotations, ref List<Matrix> translations)
        {
            int nSets = worldPointSets.Count;
            int nPoints = 0;

            for (int i = 0; i < nSets; i++)
                nPoints += worldPointSets[i].Count; // for later

            var distCoeffs = Matrix.Zero(2, 1);


            //// if necessary run DLT on each point set to get initial rotation and translations
            //if (rotations == null)
            //{
            //    rotations = new List<Matrix>();
            //    translations = new List<Matrix>();

            //    for (int i = 0; i < nSets; i++)
            //    {
            //        Matrix R, t;
            //        CameraMath.DLT(cameraMatrix, distCoeffs, worldPointSets[i], imagePointSets[i], out R, out t);

            //        var r = CameraMath.RotationVectorFromRotationMatrix(R);

            //        rotations.Add(r);
            //        translations.Add(t);
            //    }
            //}

            // Levenberg-Marquardt for camera matrix (ignore lens distortion for now)

            // pack parameters into vector
            // parameters: camera has f, cx, cy; each point set has rotation + translation (6)
            //int nParameters = 3 + 6 * nSets;
            int nParameters = 6 * nSets;
            var parameters = new Matrix(nParameters, 1);

            {
                int pi = 0;
                //parameters[pi++] = cameraMatrix[0, 0]; // f
                //parameters[pi++] = cameraMatrix[0, 2]; // cx
                //parameters[pi++] = cameraMatrix[1, 2]; // cy
                for (int i = 0; i < nSets; i++)
                {
                    parameters[pi++] = rotations[i][0];
                    parameters[pi++] = rotations[i][1];
                    parameters[pi++] = rotations[i][2];
                    parameters[pi++] = translations[i][0];
                    parameters[pi++] = translations[i][1];
                    parameters[pi++] = translations[i][2];
                }
            }

            // size of our error vector
            int nValues = nPoints * 2; // each component (x,y) is a separate entry



            LevenbergMarquardt.Function function = delegate (Matrix p)
            {
                var fvec = new Matrix(nValues, 1);

                // unpack parameters
                int pi = 0;
                //double f = p[pi++];
                //double cx = p[pi++];
                //double cy = p[pi++];

                var K = Matrix.Identity(3, 3);
                //K[0, 0] = f;
                //K[1, 1] = f;
                //K[0, 2] = cx;
                //K[1, 2] = cy;

                K[0, 0] = cameraMatrix[0, 0];
                K[1, 1] = cameraMatrix[1, 1];
                K[0, 2] = cameraMatrix[0, 2];
                K[1, 2] = cameraMatrix[1, 2];


                var d = Matrix.Zero(2, 1);

                int fveci = 0;

                for (int i = 0; i < nSets; i++)
                {
                    var rotation = new Matrix(3, 1);
                    rotation[0] = p[pi++];
                    rotation[1] = p[pi++];
                    rotation[2] = p[pi++];
                    var R = RotationMatrixFromRotationVector(rotation);

                    var t = new Matrix(3, 1);
                    t[0] = p[pi++];
                    t[1] = p[pi++];
                    t[2] = p[pi++];

                    var worldPoints = worldPointSets[i];
                    var imagePoints = imagePointSets[i];
                    var x = new Matrix(3, 1);

                    for (int j = 0; j < worldPoints.Count; j++)
                    {
                        // transform world point to local camera coordinates
                        x.Mult(R, worldPoints[j]);
                        x.Add(t);

                        // fvec_i = y_i - f(x_i)
                        double u, v;
                        CameraMath.Project(K, d, x[0], x[1], x[2], out u, out v);

                        var imagePoint = imagePoints[j];
                        fvec[fveci++] = imagePoint.X - u;
                        fvec[fveci++] = imagePoint.Y - v;
                    }
                }
                return fvec;
            };

            // optimize
            var calibrate = new LevenbergMarquardt(function);
            calibrate.minimumReduction = 1.0e-4;
            calibrate.Minimize(parameters);

            //while (calibrate.State == LevenbergMarquardt.States.Running)
            //{
            //    var rmsError = calibrate.MinimizeOneStep(parameters);
            //    Console.WriteLine("rms error = " + rmsError);
            //}
            //for (int i = 0; i < nParameters; i++)
            //    Console.WriteLine(parameters[i] + "\t");
            //Console.WriteLine();

            // unpack parameters
            {
                int pi = 0;
                //double f = parameters[pi++];
                //double cx = parameters[pi++];
                //double cy = parameters[pi++];
                //cameraMatrix[0, 0] = f;
                //cameraMatrix[1, 1] = f;
                //cameraMatrix[0, 2] = cx;
                //cameraMatrix[1, 2] = cy;

                for (int i = 0; i < nSets; i++)
                {
                    rotations[i][0] = parameters[pi++];
                    rotations[i][1] = parameters[pi++];
                    rotations[i][2] = parameters[pi++];

                    translations[i][0] = parameters[pi++];
                    translations[i][1] = parameters[pi++];
                    translations[i][2] = parameters[pi++];
                }
            }

            return calibrate.RMSError;
        }
        public void OptimizePose()
        {
            UnifyPose();

            // joint estimate of projector and camera pose

            // minimize wrt T_CjW, T_WPk:  Sum_ijk  v_ijk [ p_k( T_WPk T_CjW x_i ) - y_ik ]^2

            // cameras observe points x_i (in camera coords)
            // point x_i is observed to project to point y_ik in projector k
            // v_ijk === 1 if point i is observed by camera j and imaged by projector k
            // p_k(x) projects point x in projector k; x in projector coordinates
            // T_CjW camera j local coordinates to world coordinates
            // T_WPk world to projector k coorindates

            // efficient implementation: list of points x_ijk for which v_ijk != 0; store j, k with each point x_i
            // solve for C_j, P_k; C_0 is not in the set of parameters

            // parameters: for each projector and camera: 1 rotation + 1 translation = 6 parameters
            //    We leave T_C0W fixed, so have 6 * (numProjectors + numCameras - 1) parameters
            int nParameters = 6 * (projectors.Count + cameras.Count - 1);
            //double[] parameters = new double[nParameters];
            var parameters = new Matrix(nParameters, 1);

            // loop over room.cameras, room.projectors to form up parameters array
            {
                int pi = 0; // index into our parameter array
                for (int i = 1; i < cameras.Count; i++) // skip first one, which is our root
                {
                    var T = cameras[i].pose;
                    var R = new Matrix(3, 3);
                    var t = new Matrix(3, 1);
                    for (int ii = 0; ii < 3; ii++)
                    {
                        t[ii] = T[ii, 3];
                        for (int jj = 0; jj < 3; jj++)
                            R[ii, jj] = T[ii, jj];
                    }

                    var r = CameraMath.RotationVectorFromRotationMatrix(R);

                    for (int ii = 0; ii < 3; ii++)
                        parameters[pi++] = r[ii];
                    for (int ii = 0; ii < 3; ii++)
                        parameters[pi++] = t[ii];
                }

                for (int i = 0; i < projectors.Count; i++)
                {
                    var T = projectors[i].pose;
                    var R = new Matrix(3, 3);
                    var t = new Matrix(3, 1);
                    for (int ii = 0; ii < 3; ii++)
                    {
                        t[ii] = T[ii, 3];
                        for (int jj = 0; jj < 3; jj++)
                            R[ii, jj] = T[ii, jj];
                    }

                    var r = CameraMath.RotationVectorFromRotationMatrix(R);

                    for (int ii = 0; ii < 3; ii++)
                        parameters[pi++] = r[ii];
                    for (int ii = 0; ii < 3; ii++)
                        parameters[pi++] = t[ii];
                }
            }

            // count the number of values
            // use only inliers from previous step
            int nValues = 0;
            foreach (var projector in projectors)
                foreach (var camera in projector.calibrationPointSets.Keys)
                    nValues += projector.calibrationPointSets[camera].worldPointInliers.Count * 2; // count components

            LevenbergMarquardt.Function optimize = delegate(Matrix p)
            {
                var fvec = new Matrix(nValues, 1);

                // convert p to transforms etc.
                // convert back to transforms and put back in our structures
                int pi = 0; // index into our parameter array
                for (int i = 1; i < cameras.Count; i++) // skip first one, which is our root
                {
                    var r = new Matrix(3, 1);
                    r[0] = p[pi++];
                    r[1] = p[pi++];
                    r[2] = p[pi++];
                    var R = CameraMath.RotationMatrixFromRotationVector(r);

                    var t = new Matrix(3, 1);
                    t[0] = p[pi++];
                    t[1] = p[pi++];
                    t[2] = p[pi++];

                    var T = new Matrix(4, 4);
                    T.Identity();
                    for (int ii = 0; ii < 3; ii++)
                    {
                        for (int jj = 0; jj < 3; jj++)
                            T[ii, jj] = R[ii, jj];
                        T[ii, 3] = t[ii];
                    }
                    cameras[i].pose = T;
                }

                for (int i = 0; i < projectors.Count; i++)
                {
                    var r = new Matrix(3, 1);
                    r[0] = p[pi++];
                    r[1] = p[pi++];
                    r[2] = p[pi++];
                    var R = CameraMath.RotationMatrixFromRotationVector(r);

                    var t = new Matrix(3, 1);
                    t[0] = p[pi++];
                    t[1] = p[pi++];
                    t[2] = p[pi++];

                    var T = new Matrix(4, 4);
                    T.Identity();
                    for (int ii = 0; ii < 3; ii++)
                    {
                        for (int jj = 0; jj < 3; jj++)
                            T[ii, jj] = R[ii, jj];
                        T[ii, 3] = t[ii];
                    }
                    projectors[i].pose = T;
                }

                int fveci = 0; // index into our fvec array

                foreach (var projector in projectors)
                {
                    // T_WPk is inverse of T_PkW, projector pose
                    var T_WPk = new Matrix(4, 4);
                    T_WPk.Inverse(projector.pose);

                    foreach (var camera in projector.calibrationPointSets.Keys)
                    {
                        var cameraPoints = projector.calibrationPointSets[camera].worldPointInliers;
                        var projectorPoints = projector.calibrationPointSets[camera].imagePointInliers;

                        // transforms camera to projector coordinates
                        var T_CjW = camera.pose;
                        var T_CjPk = new Matrix(4, 4);
                        T_CjPk.Mult(T_WPk, T_CjW);

                        var cameraInProjector4 = new Matrix(4, 1);
                        cameraInProjector4[3] = 1;

                        var cameraPoint4 = new Matrix(4, 1);
                        cameraPoint4[3] = 1;

                        for (int i = 0; i < cameraPoints.Count; i++)
                        {
                            var cameraPoint = cameraPoints[i];

                            cameraPoint4[0] = cameraPoint[0];
                            cameraPoint4[1] = cameraPoint[1];
                            cameraPoint4[2] = cameraPoint[2];

                            cameraInProjector4.Mult(T_CjPk, cameraPoint4);

                            cameraInProjector4.Scale(1.0 / cameraInProjector4[3]);

                            // fvec_i = y_i - p_k( T_CjPk x_i );
                            double u, v;
                            CameraMath.Project(projector.cameraMatrix, projector.lensDistortion, cameraInProjector4[0], cameraInProjector4[1], cameraInProjector4[2], out u, out v);

                            var projectorPoint = projectorPoints[i];
                            fvec[fveci++] = projectorPoint.X - u;
                            fvec[fveci++] = projectorPoint.Y - v;
                        }
                    }
                }

                //double sum = 0;
                //for (int i = 0; i < nValues; i++)
                //    sum += fvec[i] * fvec[i];

                //double rms = Math.Sqrt(sum / (double)nValues);
                //Console.WriteLine("in functor, rms == " + rms);

                return fvec;

            };

            // TODO: maybe compute error before final optimization

            var calibrate = new LevenbergMarquardt(optimize);
            calibrate.minimumReduction = 1.0e-4;
            while (calibrate.State == LevenbergMarquardt.States.Running)
            {
                double rmsError = calibrate.MinimizeOneStep(parameters);
                Console.WriteLine("rms error = " + rmsError);
            }

            //for (int i = 0; i < nParameters; i++)
            //    Console.WriteLine(parameters[i] + "\t");
            //Console.WriteLine();

            // convert back to transforms and put back in our structures
            {
                int pi = 0; // index into our parameter array
                for (int i = 1; i < cameras.Count; i++) // skip first one, which is our root
                {
                    var r = new Matrix(3, 1);
                    r[0] = parameters[pi++];
                    r[1] = parameters[pi++];
                    r[2] = parameters[pi++];
                    var R = CameraMath.RotationMatrixFromRotationVector(r);

                    var t = new Matrix(3, 1);
                    t[0] = parameters[pi++];
                    t[1] = parameters[pi++];
                    t[2] = parameters[pi++];

                    var T = new Matrix(4, 4);
                    T.Identity();
                    for (int ii = 0; ii < 3; ii++)
                    {
                        for (int jj = 0; jj < 3; jj++)
                            T[ii, jj] = R[ii, jj];
                        T[ii, 3] = t[ii];
                    }
                    cameras[i].pose = T;
                }

                for (int i = 0; i < projectors.Count; i++)
                {
                    var r = new Matrix(3, 1);
                    r[0] = parameters[pi++];
                    r[1] = parameters[pi++];
                    r[2] = parameters[pi++];
                    var R = CameraMath.RotationMatrixFromRotationVector(r);

                    var t = new Matrix(3, 1);
                    t[0] = parameters[pi++];
                    t[1] = parameters[pi++];
                    t[2] = parameters[pi++];

                    var T = new Matrix(4, 4);
                    T.Identity();
                    for (int ii = 0; ii < 3; ii++)
                    {
                        for (int jj = 0; jj < 3; jj++)
                            T[ii, jj] = R[ii, jj];
                        T[ii, 3] = t[ii];
                    }
                    projectors[i].pose = T;
                }
            }

            Console.WriteLine("elapsed time " + stopWatch.ElapsedMilliseconds);
        }
Beispiel #9
0
        public static double CalibrateCameraExtrinsicsOnly(List <List <Matrix> > worldPointSets, List <List <System.Drawing.PointF> > imagePointSets,
                                                           Matrix cameraMatrix, ref List <Matrix> rotations, ref List <Matrix> translations)
        {
            int nSets   = worldPointSets.Count;
            int nPoints = 0;

            for (int i = 0; i < nSets; i++)
            {
                nPoints += worldPointSets[i].Count; // for later
            }
            var distCoeffs = Matrix.Zero(2, 1);


            //// if necessary run DLT on each point set to get initial rotation and translations
            //if (rotations == null)
            //{
            //    rotations = new List<Matrix>();
            //    translations = new List<Matrix>();

            //    for (int i = 0; i < nSets; i++)
            //    {
            //        Matrix R, t;
            //        CameraMath.DLT(cameraMatrix, distCoeffs, worldPointSets[i], imagePointSets[i], out R, out t);

            //        var r = CameraMath.RotationVectorFromRotationMatrix(R);

            //        rotations.Add(r);
            //        translations.Add(t);
            //    }
            //}

            // Levenberg-Marquardt for camera matrix (ignore lens distortion for now)

            // pack parameters into vector
            // parameters: camera has f, cx, cy; each point set has rotation + translation (6)
            //int nParameters = 3 + 6 * nSets;
            int nParameters = 6 * nSets;
            var parameters  = new Matrix(nParameters, 1);

            {
                int pi = 0;
                //parameters[pi++] = cameraMatrix[0, 0]; // f
                //parameters[pi++] = cameraMatrix[0, 2]; // cx
                //parameters[pi++] = cameraMatrix[1, 2]; // cy
                for (int i = 0; i < nSets; i++)
                {
                    parameters[pi++] = rotations[i][0];
                    parameters[pi++] = rotations[i][1];
                    parameters[pi++] = rotations[i][2];
                    parameters[pi++] = translations[i][0];
                    parameters[pi++] = translations[i][1];
                    parameters[pi++] = translations[i][2];
                }
            }

            // size of our error vector
            int nValues = nPoints * 2; // each component (x,y) is a separate entry



            LevenbergMarquardt.Function function = delegate(Matrix p)
            {
                var fvec = new Matrix(nValues, 1);

                // unpack parameters
                int pi = 0;
                //double f = p[pi++];
                //double cx = p[pi++];
                //double cy = p[pi++];

                var K = Matrix.Identity(3, 3);
                //K[0, 0] = f;
                //K[1, 1] = f;
                //K[0, 2] = cx;
                //K[1, 2] = cy;

                K[0, 0] = cameraMatrix[0, 0];
                K[1, 1] = cameraMatrix[1, 1];
                K[0, 2] = cameraMatrix[0, 2];
                K[1, 2] = cameraMatrix[1, 2];


                var d = Matrix.Zero(2, 1);

                int fveci = 0;

                for (int i = 0; i < nSets; i++)
                {
                    var rotation = new Matrix(3, 1);
                    rotation[0] = p[pi++];
                    rotation[1] = p[pi++];
                    rotation[2] = p[pi++];
                    var R = RotationMatrixFromRotationVector(rotation);

                    var t = new Matrix(3, 1);
                    t[0] = p[pi++];
                    t[1] = p[pi++];
                    t[2] = p[pi++];

                    var worldPoints = worldPointSets[i];
                    var imagePoints = imagePointSets[i];
                    var x           = new Matrix(3, 1);

                    for (int j = 0; j < worldPoints.Count; j++)
                    {
                        // transform world point to local camera coordinates
                        x.Mult(R, worldPoints[j]);
                        x.Add(t);

                        // fvec_i = y_i - f(x_i)
                        double u, v;
                        CameraMath.Project(K, d, x[0], x[1], x[2], out u, out v);

                        var imagePoint = imagePoints[j];
                        fvec[fveci++] = imagePoint.X - u;
                        fvec[fveci++] = imagePoint.Y - v;
                    }
                }
                return(fvec);
            };

            // optimize
            var calibrate = new LevenbergMarquardt(function);

            calibrate.minimumReduction = 1.0e-4;
            calibrate.Minimize(parameters);

            //while (calibrate.State == LevenbergMarquardt.States.Running)
            //{
            //    var rmsError = calibrate.MinimizeOneStep(parameters);
            //    Console.WriteLine("rms error = " + rmsError);
            //}
            //for (int i = 0; i < nParameters; i++)
            //    Console.WriteLine(parameters[i] + "\t");
            //Console.WriteLine();

            // unpack parameters
            {
                int pi = 0;
                //double f = parameters[pi++];
                //double cx = parameters[pi++];
                //double cy = parameters[pi++];
                //cameraMatrix[0, 0] = f;
                //cameraMatrix[1, 1] = f;
                //cameraMatrix[0, 2] = cx;
                //cameraMatrix[1, 2] = cy;

                for (int i = 0; i < nSets; i++)
                {
                    rotations[i][0] = parameters[pi++];
                    rotations[i][1] = parameters[pi++];
                    rotations[i][2] = parameters[pi++];

                    translations[i][0] = parameters[pi++];
                    translations[i][1] = parameters[pi++];
                    translations[i][2] = parameters[pi++];
                }
            }

            return(calibrate.RMSError);
        }