Merge pull request #2892 from savuor:posegraph_no_ceres

Pose Graph rewritten without Ceres

* Works well on g2o dataset, cumulative:
1. Pose3d done w/o Eigen types;
2. PoseGraph nodes vector<Node> -> map<int, Node>
3. Eigen is not used in cost function or parametrization
4. Cost function debugged & fixed (original one was wrong), rewritten from Automatic to Analytic

* g2o dataset reading added to PoseGraph

* sparse solver fixes from DynaFu draft

* Eigen cost function and parametrization removed + g2o reading fixed

* refactored: pose error, pose graph edge, pose graph node

* sparse solve: templated

* MyOptimize(): 1st version

* several fixes and TODOs for future

* sparse block matrix: val functions, template type

* works at Ceres quality (cleanup needed)

* MyOptimize() is set to default optimizer

* Ceres thrown away, PoseGraph class and header/source code reorganized

* pose, node, edge -> nested for PoseGraph

* warnings fixed

* jacobiScaling disabled for better performance + minors

* trailing whitespace fixed

* more warnings fixed

* message added: Eigen is required for build + minors

* trying to fix warning

* try to fix "unreachable code" warning

* trying to fix unreachable code, pt.3

* trying to fix unreachable code, pt. 5

* trying to fix unreachable code, pt. the worst + minors

* try to fix unreachable code, pt. the ugliest

* trying to fix unreachable code, pt. the grumpiest

* cout -> CV_LOG_INFO

* quat matrix functions moved outside cv and kinfu namespaces

* unused function fix

* pose graph made public (but in detail namespace) + test for pose graph

* minor: prints

* Pose Graph interface settled

* Pose graph interface and its use updated

* cos -> std::cos

* cout -> CV_LOG_INFO

* pose graph interface updated: implementation

* Pose Graph Node and Edge: extra fields dropped

* more minor refactor-like fixes

* return and finish condition fixed

* more updates to test

* test disabled for Debug builds because 400 sec is too much

* whitespace

* Disable pose graph test if there's no Eigen

* more unused vars

* fixing unused function warning

* less includes

* "verbose" removed

* write obj to file only when debug level is raised

* License + include guard

* skip test using tags and SkipTestException

* suppress "unused function" warning

* minor

modules/rgbd/include/opencv2/rgbd.hpp

@@ -14,6 +14,7 @@
 #include "opencv2/rgbd/kinfu.hpp"
 #include "opencv2/rgbd/dynafu.hpp"
 #include "opencv2/rgbd/large_kinfu.hpp"
+#include "opencv2/rgbd/detail/pose_graph.hpp"
 
 
 /** @defgroup rgbd RGB-Depth Processing