Added stereo multi-camera support (#884)

* Integrated OpenGV

* Fixed build without opengv

* Cmake: moved OpenGV dependency status under solvers group

* Added multi-stereocamera models support

* Fixed OpenGV 0 sample error when one of the camera doesn't have features. Fixed g2o BA id offset with multi-camera.

* Fixed multicam 3d points generated from stereo correspondences

* db: Fixed multi stereo models not loaded correctly

* gui: fixed stereo rectification option, RegVis: fixed projection error with old databases (image size not set in calibration)

* OdomF2M: Fixed map.at error when bundle adjustment is not used

* depthai: added imu firmware update option for convenience

* Fixed various refactor errors

* Moved "large number stereo correspondences rejected" warning outside computeCorrespondences function for multicam

* Added error log if ba correspondences are computed with empty signatures

* fixed compilation errors with latest opencv

Co-authored-by: mathieu86 <mathieu@robust.ai>

corelib/src/Stereo.cpp

@@ -148,18 +148,6 @@ std::vector<cv::Point2f> StereoOpticalFlow::computeCorrespondences(
 	}
 	UDEBUG("total=%d countFlowRejected=%d countDisparityRejected=%d", (int)status.size(), countFlowRejected, countDisparityRejected);
 
-	if(countFlowRejected + countDisparityRejected > (int)status.size()/2)
-	{
-		UWARN("A large number (%d/%d) of stereo correspondences are rejected! "
-				"Optical flow may have failed because images are not calibrated, "
-				"the background is too far (no disparity between the images), "
-				"maximum disparity may be too small (%f) or that exposure between "
-				"left and right images is too different.",
-				countFlowRejected+countDisparityRejected,
-				(int)status.size(),
-				this->maxDisparity());
-	}
-
 	return rightCorners;
 }