fix build errors with opencv2, added Transform::getClosestTransform() function for convenience.

corelib/include/rtabmap/core/IMU.h

@@ -65,7 +65,6 @@ public:
 		return localTransform_.isNull();
 	}
 
-
 private:
 	cv::Vec4d orientation_;
 	cv::Mat orientationCovariance_; // 3x3 double Row major about x, y, z axes, empty if orientation is not set

corelib/include/rtabmap/core/Transform.h

@@ -31,6 +31,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <rtabmap/core/RtabmapExp.h>
 #include <vector>
 #include <string>
+#include <map>
 #include <Eigen/Core>
 #include <Eigen/Geometry>
 #include <opencv2/core/core.hpp>
@@ -149,6 +150,11 @@ public:
 	static Transform fromString(const std::string & string);
 	static bool canParseString(const std::string & string);
 
+	static Transform getClosestTransform(
+				const std::map<double, Transform> & tfBuffer,
+				const double & stamp,
+				double * stampDiff = 0);
+
 private:
 	cv::Mat data_;
 };

corelib/include/rtabmap/core/odometry/OdometryF2M.h

@@ -56,7 +56,6 @@ public:
 
 private:
 	virtual Transform computeTransform(SensorData & data, const Transform & guess = Transform(), OdometryInfo * info = 0);
-	Transform getClosestIMU(const double & stamp, double & stampDiff) const;
 
 private:
 	//Parameters