Export the proto description from cartographer

1. Clone cartographer project to <CARTOGRAPHER_PATH>
2. export all proto files to python find $CARTOGRAPHER_PATH -name *.proto -printf "%P\n" -exec protoc -I=$CARTOGRAPHER_PATH --python_out=src/ {} \;
3. run python setup.py install

python main.py info --inputfile=<*.pbstream file> to print a summary about a file.

This is an example output for the b3-2016-04-05-14-14-00.bag used in this demo

Info about: ./b3-2016-04-05-14-14-00.bag.pbstream
Serialization Header-Format Version: 2
Fieldname                            	#Entries
Field: pose_graph                    	     1 entry
Field: all_trajectory_builder_options	     1 entry
Field: submap                        	   136 entries
Field: node                          	 21679 entries
Field: trajectory_data               	     1 entry
Field: imu_data                      	305059 entries

Process finished with exit code 0

python main.py trajectory --inputfile=<*.pbstream file> plots the trajectory using open3d