[Bf-blender-cvs] SVN commit: /data/svn/bf-blender [50781] trunk/blender/extern/libmv/libmv: Make Euclidean resection "always" succeed.
Keir Mierle
mierle at gmail.com
Thu Sep 20 20:55:44 CEST 2012
Revision: 50781
http://projects.blender.org/scm/viewvc.php?view=rev&root=bf-blender&revision=50781
Author: keir
Date: 2012-09-20 18:55:44 +0000 (Thu, 20 Sep 2012)
Log Message:
-----------
Make Euclidean resection "always" succeed.
The Euclidean resection code had a magical constant, 1e-3, used to
compare the results of solving an equation. This failure detection
was well-intended, trying to prevent poor solutions from getting
made without notifying the caller. Unfortunately in practice, this
threshold is too conservative. Furthermore, it is not clear the
threshold should exist at all; the purpose of the Euclidean
resection is to come up with the best solution it can; other
methods (e.g. reprojection error) should be used to compare
whether the method succeeded.
This commit changes the Euclidean EPnP code to always succeed,
causing the previous fallback to projective resection to never
run. In most cases, this will result in better reconstructions.
This should, in most cases, fix the dreaded "flipping" problem.
Modified Paths:
--------------
trunk/blender/extern/libmv/libmv/multiview/euclidean_resection.cc
trunk/blender/extern/libmv/libmv/multiview/euclidean_resection.h
trunk/blender/extern/libmv/libmv/numeric/levenberg_marquardt.h
trunk/blender/extern/libmv/libmv/simple_pipeline/pipeline.cc
trunk/blender/extern/libmv/libmv/simple_pipeline/resect.cc
Modified: trunk/blender/extern/libmv/libmv/multiview/euclidean_resection.cc
===================================================================
--- trunk/blender/extern/libmv/libmv/multiview/euclidean_resection.cc 2012-09-20 12:59:16 UTC (rev 50780)
+++ trunk/blender/extern/libmv/libmv/multiview/euclidean_resection.cc 2012-09-20 18:55:44 UTC (rev 50781)
@@ -535,7 +535,16 @@
vector<Vec3> ts(3);
Vec rmse(3);
- // TODO(julien): Document where the "1e-3" magical constant comes from below.
+ // At one point this threshold was 1e-3, and caused no end of problems in
+ // Blender by causing frames to not resect when they would have worked fine.
+ // When the resect failed, the projective followup is run leading to worse
+ // results, and often the dreaded "flipping" where objects get flipped
+ // between frames. Instead, disable the check for now, always succeeding. The
+ // ultimate check is always reprojection error anyway.
+ //
+ // TODO(keir): Decide if setting this to infinity, effectively disabling the
+ // check, is the right approach. So far this seems the case.
+ double kSuccessThreshold = std::numeric_limits<double>::max();
// Find the first possible solution for R, t corresponding to:
// Betas = [b00 b01 b11 b02 b12 b22 b03 b13 b23 b33]
@@ -548,7 +557,7 @@
Eigen::JacobiSVD<Mat> svd_of_l4(l_6x4,
Eigen::ComputeFullU | Eigen::ComputeFullV);
Vec4 b4 = svd_of_l4.solve(rho);
- if ((l_6x4 * b4).isApprox(rho, 1e-3)) {
+ if ((l_6x4 * b4).isApprox(rho, kSuccessThreshold)) {
if (b4(0) < 0) {
b4 = -b4;
}
@@ -574,7 +583,7 @@
Vec3 b3 = svdOfL3.solve(rho);
VLOG(2) << " rho = " << rho;
VLOG(2) << " l_6x3 * b3 = " << l_6x3 * b3;
- if ((l_6x3 * b3).isApprox(rho, 1e-3)) {
+ if ((l_6x3 * b3).isApprox(rho, kSuccessThreshold)) {
if (b3(0) < 0) {
betas(0) = std::sqrt(-b3(0));
betas(1) = (b3(2) < 0) ? std::sqrt(-b3(2)) : 0;
@@ -605,7 +614,7 @@
Eigen::JacobiSVD<Mat> svdOfL5(l_6x5,
Eigen::ComputeFullU | Eigen::ComputeFullV);
Vec5 b5 = svdOfL5.solve(rho);
- if ((l_6x5 * b5).isApprox(rho, 1e-3)) {
+ if ((l_6x5 * b5).isApprox(rho, kSuccessThreshold)) {
if (b5(0) < 0) {
betas(0) = std::sqrt(-b5(0));
if (b5(2) < 0) {
Modified: trunk/blender/extern/libmv/libmv/multiview/euclidean_resection.h
===================================================================
--- trunk/blender/extern/libmv/libmv/multiview/euclidean_resection.h 2012-09-20 12:59:16 UTC (rev 50780)
+++ trunk/blender/extern/libmv/libmv/multiview/euclidean_resection.h 2012-09-20 18:55:44 UTC (rev 50781)
@@ -29,6 +29,9 @@
enum ResectionMethod {
RESECTION_ANSAR_DANIILIDIS,
+
+ // The "EPnP" algorithm by Lepetit et al.
+ // http://cvlab.epfl.ch/~lepetit/papers/lepetit_ijcv08.pdf
RESECTION_EPNP,
};
Modified: trunk/blender/extern/libmv/libmv/numeric/levenberg_marquardt.h
===================================================================
--- trunk/blender/extern/libmv/libmv/numeric/levenberg_marquardt.h 2012-09-20 12:59:16 UTC (rev 50780)
+++ trunk/blender/extern/libmv/libmv/numeric/levenberg_marquardt.h 2012-09-20 18:55:44 UTC (rev 50781)
@@ -124,11 +124,11 @@
Parameters dx, x_new;
int i;
for (i = 0; results.status == RUNNING && i < params.max_iterations; ++i) {
- VLOG(1) << "iteration: " << i;
- VLOG(1) << "||f(x)||: " << f_(x).norm();
- VLOG(1) << "max(g): " << g.array().abs().maxCoeff();
- VLOG(1) << "u: " << u;
- VLOG(1) << "v: " << v;
+ VLOG(3) << "iteration: " << i;
+ VLOG(3) << "||f(x)||: " << f_(x).norm();
+ VLOG(3) << "max(g): " << g.array().abs().maxCoeff();
+ VLOG(3) << "u: " << u;
+ VLOG(3) << "v: " << v;
AMatrixType A_augmented = A + u*AMatrixType::Identity(J.cols(), J.cols());
Solver solver(A_augmented);
Modified: trunk/blender/extern/libmv/libmv/simple_pipeline/pipeline.cc
===================================================================
--- trunk/blender/extern/libmv/libmv/simple_pipeline/pipeline.cc 2012-09-20 12:59:16 UTC (rev 50780)
+++ trunk/blender/extern/libmv/libmv/simple_pipeline/pipeline.cc 2012-09-20 18:55:44 UTC (rev 50781)
@@ -242,9 +242,9 @@
(double)tot_resects/(max_image));
if (PipelineRoutines::Resect(reconstructed_markers, reconstruction, true)) {
num_resects++;
- LG << "Ran Resect() for image " << image;
+ LG << "Ran final Resect() for image " << image;
} else {
- LG << "Failed Resect() for image " << image;
+ LG << "Failed final Resect() for image " << image;
}
}
}
Modified: trunk/blender/extern/libmv/libmv/simple_pipeline/resect.cc
===================================================================
--- trunk/blender/extern/libmv/libmv/simple_pipeline/resect.cc 2012-09-20 12:59:16 UTC (rev 50780)
+++ trunk/blender/extern/libmv/libmv/simple_pipeline/resect.cc 2012-09-20 18:55:44 UTC (rev 50781)
@@ -108,6 +108,10 @@
// printf("Resection for image %d failed\n", markers[0].image);
LG << "Resection for image " << markers[0].image << " failed;"
<< " trying fallback projective resection.";
+
+ LG << "No fallback; failing resection for " << markers[0].image;
+ return false;
+
if (!final_pass) return false;
// Euclidean resection failed. Fall back to projective resection, which is
// less reliable but better conditioned when there are many points.
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