OptimizerG2O::optimizeBA(): should we track edge outliers instead of 3D point outliers?

[matlabbe]

I think here we should track 2D edge outliers instead of 3D points. Only when the 3D points with all 2D references as outliers would be reset to its original position. optimizeBA() would return not a list of 3D points outliers, but a corresponding list of 2D outliers (matching the wordReferences map instead)

rtabmap/corelib/src/optimizer/OptimizerG2O.cpp

Lines 1962 to 2000 in b47c409

	if((*iter)->level() == 0 && (*iter)->chi2() > (*iter)->robustKernel()->delta())
	{
	(*iter)->setLevel(1);
	++outliersCount;
	double d = 0.0;
	#ifdef RTABMAP_ORB_SLAM
	if(dynamic_cast<g2o::EdgeStereoSE3ProjectXYZ*>(*iter) != 0)
	{
	d = ((g2o::EdgeStereoSE3ProjectXYZ*)(*iter))->measurement()[0]-((g2o::EdgeStereoSE3ProjectXYZ*)(*iter))->measurement()[2];
	}
	//UDEBUG("Ignoring edge (%d<->%d) d=%f var=%f kernel=%f chi2=%f", (*iter)->vertex(0)->id()-stepVertexId, (*iter)->vertex(1)->id(), d, 1.0/((g2o::EdgeStereoSE3ProjectXYZ*)(*iter))->information()(0,0), (*iter)->robustKernel()->delta(), (*iter)->chi2());
	#else
	if(dynamic_cast<g2o::EdgeProjectP2SC*>(*iter) != 0)
	{
	d = ((g2o::EdgeProjectP2SC*)(*iter))->measurement()[0]-((g2o::EdgeProjectP2SC*)(*iter))->measurement()[2];
	}
	//UDEBUG("Ignoring edge (%d<->%d) d=%f var=%f kernel=%f chi2=%f", (*iter)->vertex(0)->id()-stepVertexId, (*iter)->vertex(1)->id(), d, 1.0/((g2o::EdgeProjectP2SC*)(*iter))->information()(0,0), (*iter)->robustKernel()->delta(), (*iter)->chi2());
	#endif
	cv::Point3f pt3d;
	if((*iter)->vertex(0)->id() > negVertexOffset)
	{
	pt3d = points3DMap.at(negVertexOffset - (*iter)->vertex(0)->id());
	}
	else
	{
	pt3d = points3DMap.at((*iter)->vertex(0)->id()-stepVertexId);
	}
	((g2o::VertexSBAPointXYZ*)(*iter)->vertex(0))->setEstimate(Eigen::Vector3d(pt3d.x, pt3d.y, pt3d.z));
	if(outliers)
	{
	outliers->insert((*iter)->vertex(0)->id()-stepVertexId);
	}
	if(d < 5.0)
	{
	outliersCountFar++;
	}
	}

Ref: http://official-rtab-map-forum.206.s1.nabble.com/RTAB-Map-and-COLMAP-tp9344p11536.html