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// Copyright (c) 2009 libmv authors.
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to
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// deal in the Software without restriction, including without limitation the
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// rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
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// sell copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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// Compute the projection matrix from a set of 3D points X and their
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// projections x = PX in 2D. This is useful if a point cloud is reconstructed.
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// Algorithm is the standard DLT as described in Hartley & Zisserman, page 179.
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#ifndef LIBMV_MULTIVIEW_RESECTION_H
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#define LIBMV_MULTIVIEW_RESECTION_H
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#include "libmv/logging/logging.h"
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#include "libmv/numeric/numeric.h"
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// x's are 2D image coordinates, (x,y,1), and X's are homogeneous four vectors.
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void Resection(const Matrix<T, 2, Dynamic> &x,
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const Matrix<T, 4, Dynamic> &X,
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assert(X.cols() == N);
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Matrix<T, Dynamic, 12> design(2*N, 12);
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for (int i = 0; i < N; i++) {
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// See equation (7.2) on page 179 of H&Z.
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design.template block<1,4>(2*i, 4) = -X.col(i).transpose();
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design.template block<1,4>(2*i, 8) = yi*X.col(i).transpose();
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design.template block<1,4>(2*i + 1, 0) = X.col(i).transpose();
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design.template block<1,4>(2*i + 1, 8) = -xi*X.col(i).transpose();
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Nullspace(&design, &p);
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} // namespace resection
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#endif // LIBMV_MULTIVIEW_RESECTION_H